PHIL 315: MODERN PHILOSOPHY

James Fieser

#CHAPTER 2

DESCARTES’ MEDITATIONS

            Descartes’ philosophy developed in the context of all of the features of Renaissance and early modern philosophy discussed in the previous chapter. Like the humanists, he rejected religious authority in the quest for scientific and philosophical knowledge. For Descartes, reason was both the foundation and guide for pursuing truth. Although Descartes was a devout Catholic, he was also influenced by the Reformation’s challenge to Church authority, particularly the challenge against medieval Aristotelianism. As noted in the previous chapter, he was an active participant in the scientific revolution in both scientific method and in particular discoveries. Finally, and perhaps most importantly, Descartes reacted strongly against the Renaissance resurgence of ancient Greek skepticism. Thus, we find in Descartes’ writings a relentless pursuit of absolute certainty. Descartes’ most famous and influential philosophical writing is his Meditations, the complete text of which is presented here. The full title of the work is Meditations on the First Philosophy: In Which the Existence of God and the Distinction Between Mind and Body are Demonstrated. The work was first published in 1641 in Latin and was translated into French in the following year by the Duc de Luynes. Descartes was so pleased with the French translation that he made some additions and endorsed it for later publication. The following text of the Meditations is based on the Latin version with additions from the French version contained in brackets.

A. DEDICATION

            Descartes dedicates the Meditations to the faculty of the Sorbonne, which was the divinity school of the University of Paris. For centuries, the Sorbonne was center of Catholic theology. By dedicating his work to the Sorbonne faculty, Descartes’ was announcing that his philosophy was consistent with traditional Catholic theology. Descartes was a devout Catholic and had no desire to offend the Church. Nevertheless, he believed that Aristotelianism had no place in the new scientific age. Cautioned by the fate of Galileo, Descartes proposed his new theories diplomatically. In his Principles of Philosophy, for example, he cautiously suggests a theory of the solar system similar to Galileo’s. he expresses his hope that his theory could “be used in Christian teaching without contradicting the text of Aristotle.”

TWO KEY ISSUES OF THE MEDITATIONS. Descartes announces at the opening that there are two driving issues behind the Meditations: proving the existence of God and the immortality of the soul through natural reason. One would expect divinity school faculty to approve of this plan. However, it is not entirely that these issues are his chief concern in the Meditations.

To the Most Wise and Illustrious the Dean and Doctors of the Sacred Faculty of Theology in Paris.

            The motive which induces me to present to you this Treatise is so excellent, and, when you become acquainted with its design, I am convinced that you will also have so excellent a motive for taking it under your protection, that I feel that I cannot do better, in order to render it in some sort acceptable to you, than in a few words to state what I have set myself to do.

            I have always considered that the two questions respecting God and the Soul were the chief of those that ought to be demonstrated by philosophical rather than theological argument. For although it is quite enough for us faithful ones to accept by means of faith the fact that the human soul does not perish with the body, and that God exists, it certainly does not seem possible ever to persuade infidels of any religion, indeed, we may almost say, of any moral virtue, unless, to begin with, we prove these two facts by means of the natural reason. And inasmuch as often in this life greater rewards are offered for vice than for virtue, few people would prefer the right to the useful, were they restrained neither by the fear of God nor the expectation of another life.

(1) How must infidels be persuaded of the existence of God and the immortality of the soul?

The Existence of God. Descartes discusses the importance that the Sorbonne faculty themselves place on rational proofs.

And although it is absolutely true that we must believe that there is a God, because we are so taught in the Holy Scriptures, and, on the other hand, that we must believe the Holy Scriptures because they come from God (the reason of this is, that, faith being a gift of God, he who gives the grace to cause us to believe other things can likewise give it to cause us to believe that he exists), we nevertheless could not place this argument before infidels, who might accuse us of reasoning in a circle. And, in truth, I have noticed that you, along with all the theologians, did not only affirm that the existence of God may be proved by the natural reason, but also that it may be inferred from the Holy Scriptures, that knowledge about Him is much clearer than that which we have of many created things, and, as a matter of fact, is so easy to acquire, that those who have it not are culpable in their ignorance. This indeed appears from the Wisdom of Solomon, chapter 8., where it is said “Nonetheless they are not to be excused; for if their understanding was so great that they could discern the world and the creatures, why did they not rather find out the Lord thereof?” and in Romans, chapter 1, it is said that they are “without excuse;” and again in the same place, by these words “that which may be known of God is evident in them,” it seems as though we were shown that all that which can be known of God may be made evident by means which are not derived from anywhere but from ourselves, and from the simple consideration of the nature of our minds. Hence I thought it not beside my purpose to inquire how this is so, and how God may be more easily and certainly known than the things of the world.

(2) What did the faculty of the Sorbonne maintain about the knowledge we may have of God?

The Immortality of the Soul. Descartes continues by noting how skeptics view the immortality of the soul and the Catholic church’s official reaction to such skepticism.

            And as regards the soul, many have considered that it is not easy to know its nature, and some have even dared to say that human reasons have convinced us that it would perish with the body, and that faith alone could believe the contrary. Nevertheless, inasmuch as the Lateran Council held under Leo X (in the eighth session) condemns these tenets, and as Leo expressly ordains Christian philosophers to refute their arguments and to employ all their powers in making known the truth, I have ventured in this treatise to undertake the same task.

(3) According to some skeptics, what is the only basis of belief in the immortality of the soul?

Rational Proofs and Method. Descartes stresses the importance of rationally demonstrating the existence of God and the immortality of the soul. He also notes that he intends to follow the method of investigation proposed in his Discourse on the Method.

            More than that, I am aware that the principal reason which causes many impious persons not to desire to believe that there is a God, and that the human soul is distinct from the body, is that they declare that until now no one has been able to demonstrate these two facts. And although I am not of their opinion but, on the contrary, hold that the greater part of the reasons which have been brought forward concerning these two questions by so many great men are, when they are rightly understood, equal to so many demonstrations, and that it is almost impossible to invent new ones, it is yet in my opinion the case that nothing more useful can be accomplished in philosophy than once for all to seek with care for the best of these reasons, and to set them forth in so clear and exact a manner, that it will henceforth be evident to everybody that they are veritable demonstrations. And, finally, inasmuch as it was desired that I should undertake this task by many who were aware that I had cultivated a certain Method for the resolution of difficulties of every kind in the Sciences -- a method which it is true is not novel, since there is nothing more ancient than the truth, but of which they were aware that I had made use successfully enough in other matters of difficulty -- I have thought that it was my duty also to make trial of it in the present matter.

(4) What kind of difficulties does Descartes believe his method of investigation can resolve?

            Now all that I could accomplish in the matter is contained in this Treatise. Not that I have here drawn together all the different reasons which might be brought forward to serve as proofs of this subject: for that never seemed to be necessary except when there was no one single proof that was certain. But I have treated the first and principal ones in such a manner that I can venture to bring them forward as very evident and very certain demonstrations. And more than that, I will say that these proofs are such that I do not think that there is any way open to the human mind by which it can ever succeed in discovering better. For the importance of the subject, and the glory of God to which all this relates, constrain me to speak here somewhat more freely of myself than is my habit. Nevertheless, whatever certainty and evidence I find in my reasons, I cannot persuade myself that all the world is capable of understanding them. Still, just as in Geometry there are many demonstrations that have been left to us by Archimedes, by Apollonius, by Pappus, and others, which are accepted by everyone as perfectly certain and evident (because they clearly contain nothing which, considered by itself, is not very easy to understand, and as all through that which follows has an exact connection with, and dependence on that which precedes), nevertheless, because they are somewhat lengthy, and demand a mind wholly devoted to their consideration, they are only taken in and understood by a very limited number of persons.

(5) What is the down side to the demonstrations given by Archimedes, Apollonius, Pappus and others?

Similarly, although I judge that those of which I here make use are equal to, or even surpass in certainty and evidence, the demonstrations of Geometry, I yet see that they cannot be adequately understood by many, both because they are also a little lengthy and dependent the one on the other, and principally because they demand a mind wholly free of prejudices, and one which can be easily detached from the affairs of the senses. And, truth to say, there are not so many in the world who are fitted for metaphysical speculations as there are for those of Geometry. And more than that. There is still this difference, that in Geometry, since each one is persuaded that nothing must be advanced of which there is not a certain demonstration, those who are not entirely adept more frequently err in approving what is false, in order to give the impression that they understand it, than in refuting the true. But the case is different in philosophy where everyone believes that all is problematical, and few give themselves to the search after truth; and the greater number, in their desire to acquire a reputation for boldness of thought, arrogantly combat the most important of truths.

(6) According to Descartes, geometricians rarely show the falsehood of accepted truths and demonstrations. By contrast, how do philosophers approach the pursuit of truth?

PLEA TO THE SORBONNE FACULTY. Descartes closes the dedication pleading with the faculty of the Sorbonne that their support and influence is necessary for the Meditations to be seen as a successful refutation of skepticism.

 That is why, whatever force there may be in my reasonings, seeing they belong to philosophy, I cannot hope that they will have much effect on the minds of men, unless you extend to them your protection. But the estimation in which you company is universally held is so great, and the name of Sorbonne carries with it so much authority, that, next to the Sacred Councils, never has such deference been paid to the judgment of any body, not only in what concerns the faith, but also in what regards human philosophy as well. Everyone indeed believes that it is not possible to discover elsewhere more perspicacity and solidity, or more integrity and wisdom in pronouncing judgment. For this reason I request that you stoop to take the trouble in the first place of correcting this work (for being conscious not only of my infirmity, but also of my ignorance, I should not dare to state that it was free from errors). And then you may add to it these things that are lacking to it, complete those which are imperfect, and yourselves take the trouble to give a more ample explanation of those things which have need of it, or at least make me aware of the defects so that I may apply myself to remedy them. When finally the reasonings by which I prove that there is a God, and that the human soul differs from the body, will be carried to that point of perspicuity to which I am sure they can be carried in order that they may be distinguished as perfectly exact demonstrations, I hope you choose to authorize your approval and to make public testimony to their truth and certainty. When this is done, I do not doubt, I say, that henceforward all the errors and false opinions which have ever existed regarding these two questions will soon be effaced from the minds of men. For the truth itself will easily cause all men of mind and learning to subscribe to your judgment. And your authority will cause the atheists, who are usually more arrogant than learned or judicious, to rid themselves of their spirit of contradiction or lead them possibly themselves to defend the reasonings which they find being received as demonstrations by all persons of consideration, lest they appear not to understand them. And, finally, all others will easily yield to such a mass of evidence, and there will be none who dares to doubt the existence of God and the real and true distinction between the human soul and the body. It is for you now in your singular wisdom to judge of the importance of the establishment of such beliefs [you who see the disorders produced by the doubt of them]. But it would not become me to say more in consideration of the cause of God and religion to those who have always been the most worthy supports of the Catholic Church.

(7) What help does Descartes request of the Sorbonne faculty?

In addition to his Dedication, Descartes opened his meditations with a “Preface to the Reader” and a “Synopsis of the Six Following Meditations.” However, to fully follow Descartes’ comments in these, the reader must first be familiar with the Meditations. Thus, in this chapter, the “Preface” to the Meditations has been placed after Meditation Six, and the “Synopsis” has been broken into six parts and placed at the close of each of the six Meditations respectively.

B. MEDITATION I:

CONCERNING THOSE THINGS THAT CAN BE CALLED INTO DOUBT

DOUBTING THE FOUNDATIONS OF OUR KNOWLEDGE. Descartes opens his meditations indicating his desire to have only true beliefs. One way to accomplish this is to doubt everything he has learned that might be suspect of error.

            It is now some years since I detected how many were the false beliefs that I had from my earliest youth admitted as true, and how doubtful was everything I had since constructed on this basis. And from that time I was convinced that I must once for all seriously undertake to rid myself of all the opinions which I had formerly accepted, and commence to build anew from the foundation, if I wanted to establish any firm and permanent structure in the sciences. But as this enterprise appeared to be a very great one, I waited until I had attained an age so mature that I could not hope that at any later date I should be better fitted to execute my design. This reason caused me to delay so long that I should feel that I was doing wrong were I to occupy in deliberation the time that yet remains to me for action. Today, then, since very opportunely for the plan I have in view I have delivered my mind from every care [and am happily agitated by no passions] and since I have procured for myself an assured leisure in a peaceable retirement, I will at last seriously and freely address myself to the general upheaval of all my former opinions.

(1) What reason does Descartes give in the First Meditation for seriously undertaking to rid himself of his former opinions?

            Now for this object it is not necessary that I should show that all of these are false I will perhaps never arrive at this end. But inasmuch as reason already persuades me that I ought no less carefully to withhold my assent from matters which are not entirely certain and indubitable than from those which appear to me evidently to be false, if I am able to find in each one some reason to doubt, this will suffice to justify my rejecting the whole. And for that end it will not be requisite that I should examine each in particular, which would be an endless undertaking; for owing to the fact that the destruction of the foundations of necessity brings with it the downfall of the rest of the edifice, I will only in the first place attack those principles upon which all my former opinions rested.

            All that up to the present time I have accepted as most true and certain I have learned either from the senses or through the senses; but it is sometimes proved to me that these senses are deceptive, and it is wiser not to trust entirely to anything by which we have once been deceived.

(2) Descartes does not intend to doubt the truth of every specific idea that comes into his head. Rather, what does he plan to undermine?

(3) What is the main assumption which he brings under suspicion?

REASONS FOR DOUBT. In the above, Descartes proposes to systematically follow a process of doubt. The doubt is not a simply common sense one, though, as when I doubt whether black cats are harbingers of bad luck. Instead, his doubting process is philosophical one, and sometimes called “hyperbolic” (or exaggerated) doubt where he proposes to doubt anything which he has some reason to doubt. The goal of this doubting process is to arrive at a list of beliefs which are certain and indubitably true. It thus may be viewed as a systematic doubting experiment which consists in articulating reasons for doubting sensory information. When he presents the last of these reasons, there are virtually no items of knowledge he can have confidence in.

Primary and Secondary Qualities. Before turning to Descartes’ reasons for doubt, some terminological background is needed. Descartes recognizes that some perceptions seem more genuine than others. For instance, we look at an apple and perceive qualities of redness, sweet smell, roundness, and singularity. Descartes recognized that the qualities of redness and sweet smell do not really belong to the apple. Instead these qualities exist only in the mind of an observer, and are then imposed onto the apple. These have been traditionally called secondary qualities. By contrast, the qualities of roundness and singularity belong to the apple itself, and are not products of the observer’s mind. These have been termed primary qualities. For Descartes, secondary qualities arise from what he calls “objects of the senses,” and primary qualities from “objects of mathematics.” The following illustrates the connection:

                        | Objects          Qualities

_______________________________________

Secondary       |  objects          hardness, heat,

                        |  of                  light, odor, color,

                        | senses            taste, sound

                        |

Primary           | objects           quantity, shape

                        | of                   time, magnitude,

                        | mathematics

An apple would be a secondary object, or object of the senses, when we consider only its secondary qualities of redness and sweet smell. On the other hand an apple is a primary object, or object of mathematics, when we consider only its primary qualities of shape and singularity (quantity). The root of the primary/secondary distinction is the attribute of extension (or existence in space). Primary qualities are features which necessarily belong to extended objects. All secondary qualities, by contrast, do not necessarily belong to extended objects and, thus, are spectator dependent. In view of this primary/secondary distinction, when Descartes doubts the reliability of his senses, he must find reason to doubt both his primary and secondary perceptions.

Optical Illusions. Descartes begins his systematic doubting experiment by pointing out an obvious credibility problem with our senses: optical illusions.

            But it may be that although the senses sometimes deceive us concerning things which are hardly perceptible, or very far away, there are yet many others to be met with as to which we cannot reasonably have any doubt, although we recognize them by their means. For example, there is the fact that I am here, seated by the fire, attired in a dressing gown, having this paper in my hands and other similar matters. And how could I deny that these hands and this body are mine, were it not perhaps that I compare myself to certain persons, devoid of sense, whose cerebella are so troubled and clouded by the violent vapors of black bile, that they constantly assure us that they think they are kings when they are really quite poor, or that they are clothed in purple when they are really without covering, or who imagine that they have an earthenware head or are nothing but pumpkins or are made of glass. But they are mad, and I should not be any the less insane were I to follow examples so extravagant.

(4) Descartes begins doubting the reliability of his senses by noting that we perceive distant objects to be much smaller than they really are. This, though, does not undermine the general reliability of the senses. Why not?

Dream Hypothesis. Continuing his doubting experiment, Descartes suggests the possibility that he his dreaming.

            At the same time I must remember that I am a man, and that consequently I am in the habit of sleeping, and in my dreams representing to myself the same things or sometimes even less probable things, than do those who are insane in their waking moments. How often has it happened to me that in the night I dreamt that I found myself in this particular place, that I was dressed and seated near the fire, whilst in reality I was lying undressed in bed! At this moment it does indeed seem to me that it is with eyes awake that I am looking at this paper; that this head which I move is not asleep, that it is deliberately and of set purpose that I extend my hand and perceive it; what happens in sleep does not appear so clear nor so distinct as does all this. But in thinking over this I remind myself that on many occasions I have in sleep been deceived by similar illusions, and in dwelling carefully on this reflection I see so evidently that there are no certain indications by which we may clearly distinguish wakefulness from sleep that I am lost in astonishment. And my astonishment is such that it is almost capable of persuading me that I now dream.

(5) Why is Descartes almost convinced that he is sleeping?

            Now let us assume that we are asleep and that all these particulars, for example, that we open our eyes, shake our head, extend our hands, and so on, are but false delusions; and let us reflect that possibly neither our hands nor our whole body are such as they appear to us to be. At the same time we must at least confess that the things which are represented to us in sleep are like painted representations which can only have been formed as the counterparts of something real and true, and that in this way those general things at least, that is, eyes, a head, hands, and a whole body, are not imaginary things, but things really existent. For, as a matter of fact, painters, even when they study with the greatest skill to represent sirens and satyrs by forms the most strange and extraordinary, cannot give them natures which are entirely new, but merely make a certain medley of the members of different animals; or if their imagination is extravagant enough to invent something so novel that nothing similar has ever before been seen, and that then their work represents a thing purely fictitious and absolutely false, it is certain all the same that the colors of which this is composed are necessarily real. And for the same reason, although these general things, to with, [a body], eyes, a head, hands, and such like, may be imaginary, we are bound at the same time to confess that there are at least some other objects yet more simple and more universal, which are real and true; and of these just in the same way as with certain real colors, all these images of things which dwell in our thoughts, whether true and real or false and fantastic, are formed.

            To such a class of things pertains corporeal nature in general, and its extension, the figure of extended things, their quantity or magnitude and number, as also the place in which they are, the time which measures their duration, and so on.

(6) What type of information (that is, primary or secondary) comes under doubt when he considers that he may be dreaming?

            That is possibly why our reasoning is not unjust when we conclude from this that Physics, Astronomy, Medicine and all other sciences which have as their end the consideration of composite things, are very dubious and uncertain; but that Arithmetic, Geometry and other sciences of that kind which only treat of things that are very simple and very general, without taking great trouble to ascertain whether they are actually existent or not, contain some measure of certainty and an element of the indubitable. For whether I am awake or asleep, two and three together always form five, and the square can never have more than four sides, and it does not seem possible that truths so clear and apparent can be suspected of any falsity [or uncertainty].

(7) What type of knowledge remains incontestable (that is, primary or secondary), and what are the fields of study which examine this information?

The Evil Genius Hypothesis. Taking his doubts further, Descartes initially speculates that God is deceiving him about all of the things which he believes or perceives, including primary objects.

            Nevertheless I have long had fixed in my mind the belief that an all-powerful God existed by whom I have been created such as I am. But how do I know that he has not brought it to pass that there is no earth, no heaven, no extended body, no magnitude, no place, and that nevertheless [I possess the perceptions of all these things and that] they seem to me to exist just exactly as I now see them? And, besides, as I sometimes imagine that others deceive themselves in the things which they think they know best, how do I know that I am not deceived every time that I add two and three, or count the sides of a square, or judge of things yet simpler, if anything simpler can be imagined?

(8) What examples does he give to show that God could deceive him with mathematics?

This causes him problems, though, because according to traditional Christian theology, infinite goodness is one of God’s necessary attributes. If backed into a corner, some might deny God’s existence rather than admit that he is the cause of deception. With God out of the picture, though, Descartes argues that he would be even more vulnerable to deception.

But possibly God has not desired that I should be thus deceived, for he is said to be supremely good. If, however, it is contrary to his goodness to have made me such that I constantly deceive myself, it would also appear to be contrary to his goodness to permit me to be sometimes deceived, and nevertheless I cannot doubt that he does permit this.

            There may indeed be those who would prefer to deny the existence of a God so powerful, rather than believe that all other things are uncertain. But let us not oppose them for the present, and grant that all that is here said of a God is a fable. They may suppose that I have arrived at the state of being that I have reached, attributing it to fate or to accident, or making out that it is by a continual succession of antecedents, or by some other method since to err and deceive oneself is a defect. Nevertheless, as the Author to whom they assign my origin is said to be less powerful, it is clear that the probability increases that I deceive myself even more because of my imperfection. To these reasons I have certainly nothing to reply, but at the end I feel constrained to confess that there is nothing in all that I formerly believed to be true, of which I cannot in some measure doubt. This is so not merely through lack of thought or through frivolity, but for reasons which are very powerful and maturely considered. Thus, if I desire to arrive at any certainty [in the sciences], I should continue to refrain from giving credence to these opinions just as though they were evidently false.

(9) What is Descartes response to those who would deny God’s existence rather than admit that God is the cause of deception?

Descartes reflects on how far astray his doubts may take him, and to what extent they are justified.

            But it is not sufficient to have made these remarks, we must also be careful to keep them in mind. For these ancient and commonly held opinions still revert frequently to my mind, long and familiar custom having given them the right to occupy my mind against my inclination and rendered them almost masters of my belief. Nor will I ever lose the habit of deferring to them or of placing my confidence in them, so long as I consider them as they really are, that is, opinions in some measure doubtful, as I have just shown, and at the same time highly probable, so that there is much more reason to believe in than to deny them. That is why I consider that I will not be acting amiss, if, taking of set purpose a contrary belief, I allow myself to be deceived, and for a certain time pretend that all these opinions are entirely false and imaginary, until at last, having thus balanced my former prejudices with my latter [so that they cannot divert my opinions more to one side than to the other], my judgment will no longer be dominated by bad usage or turned away from the right knowledge of the truth. For I am assured that there can be neither peril nor error in this course, and that I cannot at present yield too much to distrust, since I am not considering the question of action, but only of knowledge.

(10) Discussions of skepticism during the modern period often drew a distinction between speculative and actional skepticism. A speculative skeptic merely uncovers theoretical problems, and an actional skeptic continues by recommending a course of action. With religious beliefs in particular, actional skepticism was viewed as more dangerous as it might recommend that we act as though there were no God. What kind of doubt does Descartes propose here?

            I will then suppose, not that God who is supremely good and the fountain of truth, but some evil genius not less powerful than deceitful, has employed his whole energies in deceiving me. I will consider that the heavens, the earth, colors, figures, sound, and all other external things are nothing but the illusions and dreams of which this genius has availed himself in order to lay traps for my credulity. I will consider myself as having no hands, no eyes, no flesh, no blood, nor any senses, yet falsely believing myself to possess all these things. I will remain obstinately attached to this idea, and if by this means it is not in my power to arrive at the knowledge of any truth, I may at least do what is in my power [that is, suspend my judgment], and with firm purpose avoid giving credence to any false thing, or being imposed upon by this arch deceiver, however powerful and deceptive he may be. But this task is a laborious one, and insensibly a certain lethargy leads me into the course of my ordinary life. And just as a captive who in sleep enjoys an imaginary liberty, when he begins to suspect that his liberty is but a dream, fears to awaken, and conspires with these agreeable illusions that the deception may be prolonged, so insensibly of my own accord I fall back into my former opinions, and I dread awakening from this slumber, lest the laborious wakefulness which would follow the tranquillity of this calmness should have to be spent not in daylight, but in the excessive darkness of the difficulties which have just been discussed.

(11) How does Descartes revise his doubt so not to run counter to traditional Christian belief?

(12) What external things does Descartes take to be deceptive traps of the evil genius?

SYNOPSIS. As noted, Descartes opened the Meditations with a synopsis of each of the six meditations. His synopsis of the first is as follows.

            In the first Meditation I set forth the reasons for which we may, generally speaking, doubt about all things and especially about material things, at least so long as we have no other foundations for the sciences than those which we have until now possessed. But although the utility of a doubt which is so general does not at first appear, it is at the same time very great, inasmuch as it delivers us from every kind of prejudice, and sets out for us a very simple way by which the mind may detach itself from the senses; and finally it makes it impossible for us ever to doubt those things which we have once discovered to be true.

C. MEDITATION II

 CONCERNING THE NATURE OF THE HUMAN MIND: THAT THE MIND IS MORE KNOWN THAN THE BODY

EXTENT OF HIS DOUBT. Descartes opens Meditation Two by describing the extent of his doubt. Virtually every item of knowledge he previously believed is subject to some kind of doubt.

            The Meditation of yesterday filled my mind with so many doubts that it is no longer in my power to forget them. And yet I do not see in what manner I can resolve them. And, just as if I had all of a sudden fallen into very deep water, I am so baffled that I can neither make certain of setting my feet on the bottom, nor can I swim and so support myself on the surface. I will nevertheless make an effort and follow anew the same path as that on which I yesterday entered, that is, I will proceed by setting aside all that in which the least doubt could be supposed to exist, just as if I had discovered that it was absolutely false. And I will ever follow in this road until I have met with something which is certain, or at least, if I can do nothing else, until I have learned for certain that there is nothing in the world that is certain. Archimedes, in order that he might draw the terrestrial globe out of its place, and transport it elsewhere, demanded only that one point should be fixed and immovable. In the same way I will have the right to conceive high hopes if I am happy enough to discover one thing only which is certain and indubitable.

(1) Archimedes was an ancient Greek engineer who said “give me a fulcrum and a firm point, and I alone can move the earth.” Finish this analogy: Archimedes’ ability to move the world is to a firm and immovable point just as a true philosophical system (that is, “high hopes”) is to what?

            I suppose, then, that all the things that I see are false; I persuade myself that nothing has ever existed of all that my fallacious memory represents to me. I consider that I possess no senses; I imagine that body, figure, extension, movement and place are but the fictions of my mind. What, then, can be distinguished as true? Perhaps nothing at all, unless that there is nothing in the world that is certain.

(2) What are the various things which Descartes doubts at this point in his quest?

            But how can I know there is not something different from those things that I have just considered, of which one cannot have the slightest doubt? Is there not some God, or some other being by whatever name we call it, who puts these reflections into my mind? That is not necessary, for is it not possible that I am capable of producing them myself? I myself, am I not at least something? But I have already denied that I had senses and body. Yet I hesitate, for what follows from that? Am I so dependent on body and senses that I cannot exist without these? But I was persuaded that there was nothing in all the world, that there was no heaven, no earth, that there were no minds, nor any bodies: was I not then likewise persuaded that I did not exist? Not at all; of a surety I myself did exist since I persuaded myself of something [or merely because I thought of something]. But there is some deceiver or other, very powerful and very cunning, who ever employs his ingenuity in deceiving me. Then without doubt I exist also if he deceives me, and let him deceive me as much as he will, he can never cause me to be nothing so long as I think that I am something. So that after having reflected well and carefully examined all things, we must come to the definite conclusion that this proposition: I am, I exist, is necessarily true each time that I pronounce it, or that I mentally conceive it.

(3) The one thing Descartes recognizes that he can never doubt is the fact that he exists. Why is this?

In his Discourse on the Method, Descartes summarizes the above line of reasoning in the famous phrase, “I think, therefore I am” (or in Latin, “cogito ergo sum”). Descartes borrowed this strategy from Augustine’s attempt to refute skepticism in his own day. Augustine writes, “On none of these points do I fear the arguments of the skeptics of the Academy who say: what if you are deceived? For if I am deceived, I am. For he who does not exist cannot be deceived. And if I am deceived, by this same token I am” (City of God, 11:26).

WHAT I AM. Once Descartes recognizes the indubitable truth that he exists, he then attempts to further his knowledge by discovering the type of thing he is.

            But I do not yet know clearly enough what I am, I who am certain that I am; and hence I must be careful to see that I do not imprudently take some other object in place of myself, and thus that I do not go astray in respect of this knowledge that I hold to be the most certain and most evident of all that I have formerly learned. That is why I will now consider anew what I believed myself to be before I started upon these last reflections. And of my former opinions I will withdraw all that might even in a small degree be invalidated by the reasons which I have just brought forward, in order that there may be nothing at all left beyond what is absolutely certain and indubitable.

Rational Animal. Trying to understand what he is, Descartes recalls Aristotle’s definition of a human as a rational animal.

            What then did I formerly believe myself to be? Undoubtedly I believed myself to be a human. But what is a human? Should I say a rational animal? Certainly not. For then I should have to inquire what an animal is, and what is rational. And thus from a single question I should insensibly fall into an infinitude of others more difficult; and I should not wish to waste the little time and leisure remaining to me in trying to unravel subtleties like these.

(4) Why is he dissatisfied with the answer that he is a human or rational animal?

Body and Soul. Continuing his quest for identity, he recalls a more general view he previously had of his identity, which is that he is composed of both body and soul.

But I will rather stop here to consider the thoughts which of themselves spring up in my mind, and which were not inspired by anything beyond my own nature alone when I applied myself to the consideration of my being. In the first place, then, I considered myself as having a face, hands, arms, and all that system of members composed on bones and flesh as seen in a corpse which I designated by the name of body. In addition to this I considered that I was nourished, that I walked, that I felt, and that I thought, and I referred all these actions to the soul. But I did not stop to consider what the soul was, or if I did stop, I imagined that it was something extremely rare and subtle like a wind, a flame, or an ether, which was spread throughout my grosser parts. As to body I had no manner of doubt about its nature, but thought I had a very clear knowledge of it. And if I had desired to explain it according to the notions that I had then formed of it, I should have described it as follows. By the body I understand all that which can be defined by a certain figure. It is something which can be confined in a certain place, and which can fill a given space in such a way that every other body will be excluded from it. It can be perceived either by touch, or by sight, or by hearing, or by taste, or by smell. It can be moved in many ways, not, in truth, by itself, but by something which is foreign to it, by which it is touched [and from which it receives impressions]. For to have the power of self-movement, as also of feeling or of thinking, I did not consider to belonged to the nature of body. On the contrary, I was rather astonished to find that faculties similar to them existed in some bodies.

            But what am I, now that I suppose that there is a certain genius which is extremely powerful, and, if I may say so, malicious, who employs all his powers in deceiving me? Can I affirm that I possess the least of all those things which I have just said pertain to the nature of body? I pause to consider, I revolve all these things in my mind, and I find none of which I can say that it pertains to me. It would be tedious to stop to enumerate them.

(5) Why can’t he refer to himself as a thing which has a body?

Let us pass to the attributes of soul and see if there is any one which is in me? What of nutrition or walking [the first mentioned]? But if it is so that I have no body it is also true that I can neither walk nor take nourishment. Another attribute is sensation. But one cannot feel without body, and besides I have thought I perceived many things during sleep that I recognized in my waking moments as not having been experienced at all. What of thinking? I find here that thought is an attribute that belongs to me; it alone cannot be separated from me. I am, I exist, that is certain. But how often? Just when I think; for it might possibly be the case if I ceased entirely to think, that I should likewise cease altogether to exist. I do not now admit anything which is not necessarily true: to speak accurately I am not more than a thing which thinks, that is to say a mind or a soul, or an understanding, or a reason, which are terms whose significance was formerly unknown to me. I am, however, a real thing and really exist; but what thing? I have answered: a thing which thinks.

(6) According to classical philosophers such as Plato and Aristotle, the key attributes of the soul involve eating, movement, and sensation. Why can’t he claim to have these attributes of the soul?

Other Possible Attributes. Descartes continues examining other theories of human existence and lists of human attributes.

            And what more? I will exercise my imagination [in order to see if I am not something more]. I am not a collection of members which we call the human body: I am not a subtle air distributed through these members, I am not a wind, a fire, a vapor, a breath, nor anything at all which I can imagine or conceive; because I have assumed that all these were nothing. Without changing that supposition I find that I only leave myself certain of the fact that I am somewhat. But perhaps it is true that these same things which I supposed were non-existent because they are unknown to me, are really not different from the self which I know. I am not sure about this, I will not dispute about it now. I can only give judgment on things that are known to me.

(7) What are some of the theories of human existence which Descartes rejects?

I know that I exist, and I inquire what I am, I whom I know to exist. But it is very certain that the knowledge of my existence taken in its precise significance does not depend on things whose existence is not yet known to me. Consequently it does not depend on those which I can feign in imagination. And indeed the very term feign in imagination proves to me my error, for I really do this if I imagine myself a something, since to imagine is nothing else than to contemplate the figure or image of a corporeal thing. But I already know for certain that I am, and that it may be that all these images, and, speaking generally, all things that relate to the nature of body are nothing but dreams [and chimeras]. For this reason I see clearly that I have as little reason to say, “I will stimulate my imagination in order to know more distinctly what I am,” than if I were to say, “I am now awake, and I perceive somewhat that is real and true: but because I do not yet perceive it distinctly enough, I will go to sleep of express purpose, so that my dreams may represent the perception with greatest truth and evidence.” And, thus, I know for certain that nothing of all that I can understand by means of my imagination belongs to this knowledge which I have of myself. It is necessary to withdraw the mind from this mode of thought with the utmost diligence in order that it may be able to know its own nature with perfect distinctness.

(8) Descartes can imagine various attributes he might have. What does he do with such imaginary considerations?

I am a Thinking Thing. Descartes concludes that the attribute of thinking is the only quality which he can justifiably claim at this point. But he is quick to point out that thinking is the only attribute about which he is sure -- not that thinking is the only attribute which he has. Nevertheless, this is the starting point of a radical ontological distinction which carries Descartes through his Meditations. That distinction is between thinking substance (res cogitans) and extended substance (res extensa). The two substances are mutually exclusive. A thinking substance is nonphysical or spiritual in nature, and an extended substance is physical, but not capable of consciousness or thought.

            But what then am I? A thing which thinks. What is a thing which thinks? It is a thing which doubts, understands, [conceives], affirms, denies, wills, refuses, which also imagines and feels.

(9) What, for Descartes, does thinking entail?

Descartes next justifies his claim to each of these attributes.

            Certainly it is no small matter if all these things pertain to my nature. But why should they not so pertain? Am I not that being who now doubts nearly everything, who nevertheless understands certain things, who affirms that one only is true, who denies all the others, who desires to know more, is averse from being deceived, who imagines many things, sometimes indeed despite his will, and who perceives many likewise, as by the intervention of the bodily organs? Is there nothing in all this which is as true as it is certain that I exist, even though I should always sleep and though he who has given me being employed all his ingenuity in deceiving me? Is there likewise any one of these attributes which can be distinguished from my thought, or which might be said to be separated from myself? For it is so evident of itself that it is I who doubts, who understands, and who desires, that there is no reason here to add anything to explain it. And I have certainly the power of imagining likewise; for although it may happen (as I formerly supposed) that none of the things which I imagine are true, nevertheless this power of imagining does not cease to be really in use, and it forms part of my thought. Finally, I am the same who feels, that is to say, who perceives certain things, as by the organs of sense, since in truth I see light, I hear noise, I feel heat. But it will be said that these phenomena are false and that I am dreaming. Let it be so; still it is at least quite certain that it seems to me that I see light, that I hear noise and that I feel heat. That cannot be false; properly speaking it is what is in me called feeling; and used in this precise sense that is no other thing than thinking.

(10) What justifies Descartes in claiming that he is a thing which doubts?

THE ORDER OF KNOWLEDGE: THE WAX EXAMPLE. Note Descartes’ general strategy for adding to his knowledge. He is first concerned with the issue of personal identity, and will only much later address the issue of external objects (in Meditation Six). He then anticipates the criticism that he is going about his investigation backwards. For, it seems that knowledge of external objects is more obvious and distinct than knowledge of personal identity. Everyone knows what an apple is (an external object), but few people can properly answer the question “who am I” (an issue of personal identity). Thus, it seems that Descartes should tackle the easier problem of external objects first.

            From this time I begin to know what I am with a little more clearness and distinction than before; but nevertheless it still seems to me, and I cannot prevent myself from thinking, that corporeal things, whose images are framed by thought, which are tested by the senses, are much more distinctly known than that obscure part of me which does not come under the imagination. Although really it is very strange to say that I know and understand more distinctly these things whose existence seems to me dubious, which are unknown to me, and which do not belong to me, than others of the truth of which I am convinced, which are known to me and which pertain to my real nature, in a word, than myself. But I see clearly how the case stands: my mind loves to wander, and cannot yet suffer itself to be retained within the just limits of truth. Very good, let us once more give it the freest rein, so that, when afterwards we seize the proper occasion for pulling up, it may the more easily be regulated and controlled.

Descartes does not agree that he proceeds  in a backwards fashion, and argues that our personal identity is actually more clear and fundamental than perception of external objects. He makes his case by comparing our perceptions of a piece of wax at two times: once while the wax is in a solid state, and later after the wax has been melted by a fire.

The Senses. In arguing that knowledge of the mental realm precedes knowledge of the material realm, Descartes argues that our senses alone cannot inform us of the identity of the two states of the wax.

            Let us begin by considering the most common matters, those which we believe to be the most distinctly comprehended, namely, the bodies which we touch and see; not indeed bodies in general, for these general ideas are usually a little more confused, but let us consider one body in particular. Let us take, for example, this piece of wax: it has been taken quite freshly from the hive, and it has not yet lost the sweetness of the honey which it contains; it still retains somewhat of the odor of the flowers from which it has been culled; its color, its figure, its size are apparent; it is hard, cold, easily handled, and if you strike it with the finger, it will emit a sound. Finally all the things which are requisite to cause us distinctly to recognize a body, are met with in it. But notice that while I speak and approach the fire what remained of the taste is exhaled, the smell evaporates, the color alters, the figure is destroyed, the size increases, it becomes liquid, it heats, scarcely can one handle it, and when one strikes it, now sound is emitted. Does the same wax remain after this change? We must confess that it remains; none would judge otherwise. What then did I know so distinctly in this piece of wax? It could certainly be nothing of all that the senses brought to my notice, since all these things which fall under taste, smell, sight, touch, and hearing, are found to be changed, and yet the same wax remains.

(11) Why isn’t the identity of the two states of wax established through the senses?

The Imagination. For Descartes, the continuity of the wax cannot be established though the faculty of the imagination either.

            Perhaps it was what I now think, namely, that this wax was not that sweetness of honey, nor that agreeable scent of flowers, nor that particular whiteness, nor that figure, nor that sound, but simply a body which a little while before appeared to me as perceptible under these forms, and which is now perceptible under others. But what, precisely, is it that I imagine when I form such conceptions? Let us attentively consider this, and, abstracting from all that does not belong to the wax, let us see what remains. Certainly nothing remains except a certain extended thing which is flexible and movable. But what is the meaning of flexible and movable? Is it not that I imagine that this piece of wax being round is capable of becoming square and of passing from a square to a triangular figure? No, certainly it is not that, since I imagine it admits of an infinitude of similar changes, and I nevertheless do not know how to compass the infinitude by my imagination, and consequently this conception which I have of the wax is not brought about by the faculty of imagination. What now is this extension? Is it not also unknown? For it becomes greater when the wax is melted, greater when it is boiled, and greater still when the heat increases; and I should not conceive [clearly] according to truth what wax is, if I did not think that even this piece that we are considering is capable of receiving more variations in extension than I have ever imagined.

(12) Why isn’t the identity of the two states of the wax established through the imagination?

The Mind Alone. Descartes concludes that the identity of the two states of wax is established neither by sight, nor touch, nor imagination, but by an act of the mind alone.

We must then grant that I could not even understand through the imagination what this piece of wax is, and that it is my mind alone which perceives it. I say this piece of wax in particular, for as to wax in general it is yet clearer. But what is this piece of wax which cannot be understood except by the [understanding or] mind? It is certainly the same that I see, touch, imagine, and finally it is the same which I have always believed it to be from the beginning. But what must particularly be observed is that its perception is neither an act of vision, nor of touch, nor of imagination, and has never been such although it may have appeared formerly to be so, but only an intuition of the mind, which may be imperfect and confused as it was formerly, or clear and distinct as it is at present, according as my attention is more or less directed to the elements which are found in it, and of which it is composed.

Possible Criticisms. Descartes considers possible criticisms to his conclusion that we understand the physical world through an act of the mind. In common language we claim that we “see” the same wax in its two states (as opposed to “mentally intuit” the same wax in its two states). Thus, common language seems to suggest that the continuity of the wax is a function of “seeing” (i.e., the senses).

            Yet in the meantime I am greatly astonished when I consider [the great feebleness of mind] and its proneness to fall [insensibly] into error. For although without giving expression to my thought I consider all this in my own mind, words often impede me and I am almost deceived by the terms of ordinary language. For we say that we see the same wax, if it is present, and not that we simply judge that it is the same from its having the same color and figure. From this I should conclude that I knew the wax by means of vision and not simply by the intuition of the mind; unless by chance I remember that, when looking from a window and saying I see men who pass in the street, I really do not see them, but infer that what I see is men, just as I say that I see wax. And yet what do I see from the window but hats and coats which may cover automatic machines? Yet I judge these to be men. And similarly solely by the faculty of judgment which rests in my mind, I comprehend that which I believed I saw with my eyes.

(13) When I look out the window, I conclude that we see people crossing the road. What, though, is all that appears to my senses?

Descartes considers again whether we understand the physical world through the senses and imagination together.

            A man who makes it his aim to raise his knowledge above the common should be ashamed to derive the occasion for doubting from the forms of speech invented by the vulgar. I prefer to pass on and consider whether I had a more evident and perfect conception of what the wax was when I first perceived it, and when I believed I knew it by means of the external senses or at least by the common sense as it is called (that is to say by the imaginative faculty) or whether my present conception is clearer now that I have most carefully examined what it is, and in what way it can be known. It would certainly be absurd to doubt as to this. For what was there in this first perception which was distinct? What was there which might not as well have been perceived by any of the animals? But when I distinguish the wax from its external forms, and when, just as if I had taken from it its vestments, I consider it quite naked, it is certain that although some error may still be found in my judgment, I can nevertheless not perceive it thus without a human mind.

(14) How does the wax appear to us when we inspect it with our minds (as opposed to our senses or imagination?)

Even if Descartes is wrong and we understand the wax through our senses or our imagination, he argues that the mind is still prior to sensations. For, even if he erroneously judges that the wax exists through sight or imagination, this presupposes that he himself exists.

            But finally what will I say of this mind, that is, of myself, for up to this point I do not admit in myself anything but mind? What, then, I who seem to perceive this piece of wax so distinctly, do I not know myself, not only with much more truth and certainty, but also with much more distinctness and clearness? For if I judge that the wax is or exists from the fact that I see it, it certainly follows much more clearly that I am or that I exist myself from the fact that I see it. For it may be that what I see is not really wax, it may also be that I do not possess eyes with which to see anything; but it cannot be that when I see, or (for I no longer take account of the distinction) when I think I see, that I myself who think am nothing. So if I judge that the wax exists from the fact that I touch it, the same thing will follow, namely, that I am. And if I judge that my imagination, or some other cause, whatever it is, persuades me that the wax exists, I will still conclude the same. And what I have here remarked of wax may be applied to all other things which are external to me [and which are met with outside of me]. And further, if the [notion or] perception of wax has seemed to me clearer and more distinct, not only after the sight or the touch, but also after many other causes have rendered it quite evident to me, with how much more [evidence] and distinctness must it be said that I now know myself, since all the reasons which contribute to the knowledge of wax, or any other body whatever, are yet better proofs of the nature of my mind. And there are so many other things in the mind itself which may contribute to the elucidation of its nature, that those which depend on body such as these just mentioned, hardly merit being taken into account.

(15) For Descartes, sensation and imagination are mental attributes which depend on the body. How important are they in defining the nature of the mind?

            But finally here I am, having insensibly reverted to the point I desired, for, since it is now evident to me that even bodies are not properly speaking known by the senses or by the faculty of imagination, but by the understanding only, and since they are not known from the fact that they are seen or touched, but only because they are understood, I see clearly that there is nothing which is easier for me to know than my mind. But because it is difficult to rid oneself so promptly of an opinion to which one was accustomed for so long, it will be well that I should halt a little at this point, so that by the length of my meditation I may more deeply imprint on my memory this new knowledge.

SYNOPSIS. Descartes’ synopsis of the Second Meditation (initially presented at the opening of his Meditations) is as follows.

            In the second Meditation, mind (which making use of the liberty which pertains to it) takes for granted that all those things are non-existent of whose existence it has the least doubt. Further, however, it recognizes that it is absolutely impossible that it does not itself exist. This point is likewise of the greatest moment, inasmuch as by this means a distinction is easily drawn between the things which pertain to mind -- that is to say to the intellectual nature -- and those which pertain to body.

Immortality of the Soul. In the Dedication, Descartes argues that one of the two main objectives of the Meditations is to prove the immortality of the soul. Interestingly, Descartes scarcely addresses this issue in the Meditations. His most complete discussion of the subject appears here in the Synopsis to Meditation Two. He begins his discussion by describing when the issue of immortality should be addressed in the order of his investigation.

            But because it may be that some expect from me in this place a statement of the reasons establishing the immortality of the soul, I feel that I should here make known to them that having aimed at writing nothing in all this Treatise of which I do not possess very exact demonstrations, I am obliged to follow a similar order to that made use of by the geometers, which is to begin by putting forward as premises all those things upon which the proposition that we seek depends, before coming to any conclusion regarding it. Now the first and principal matter which is requisite for thoroughly understanding the immortality of the soul is to form the clearest possible conception of it, and one which will be entirely distinct from all the conceptions which we may have of body; and in this Meditation this has been done. In addition to this it is requisite that we may be assured that all the things which we conceive clearly and distinctly are true in the very way in which we think them; and this could not be proved previously to the Fourth Mediation. Further we must have a distinct conception of corporeal nature, which is given partly in this Second, and partly in the Fifth and Sixth Meditations. And finally we should conclude from all this, that those things which we conceive clearly and distinctly as being diverse substances, as we regard mind and body to be, are really substances essentially distinct one from the other; and this is the conclusion of the Sixth Meditation.

(16) What issues must first be addressed before considering the issue of the immortality of the soul?

This is further confirmed in this same Meditation by the fact that we cannot conceive of body except in so far as it is divisible, while the mind cannot be conceived of except as indivisible. For we are not able to conceive of the half of a mind as we can do of the smallest of all bodies; so that we see that not only are their natures different but even in some respects contrary to one another. I have not however dealt further with this matter in this treatise because what I have said is sufficient to show clearly enough that the extinction of the mind does not follow from the corruption of the body, and also to give men the hope of another life after death.

One factor in establishing the immortality of the soul is showing that the soul is composed of an indestructible and unalterable substance.

I have also not dealt with this issue because the premises from which the immortality of the soul may be deduced depend on an elucidation of a complete system of Physics. This would mean to establish in the first place that all substances generally (that is to say all things which cannot exist without being created by God) are in their nature incorruptible, and that they can never cease to exist unless God, in denying to them his approval, reduce them to nothing. And secondly this means that body, regarded generally, is a substance, which is the reason why it also cannot perish, but that the human body, inasmuch as it differs from other bodies, is composed only of a certain configuration of members and of other similar accidents, while the human mind is not similarly composed of any accidents, but is a pure substance. For although all the accidents of mind be changed, although, for instance, it think certain things, will others, perceive others, etc., despite all this it does not emerge from these changes another mind. The human body on the other hand becomes a different thing from the sole fact that the figure or form of any of its portions is found to be changed. From this it follows that the human body may indeed easily enough perish, but the mind [or soul of man (I make no distinction between them)] is owing to its nature immortal.

(17) Although the material substance of the human body is in general indestructible, the composition of the body is alterable. Thus, it is not eternal. The spiritual substance of the human mind in general is also indestructible. Our minds also change when we have different perceptions. Using Aristotle’s terminology, are these substantial or accidental changes?

D. MEDITATION III:

OF GOD: THAT HE EXISTS.

            In the first paragraph of Meditation III, Descartes summarizes his progress to date. He is ready to further his knowledge.

            I will now close my eyes, I will stop my ears, I will call away all my senses, I will efface even from my thoughts all the images of corporeal things, or at least (for that is hardly possible) I will consider them as vain and false; and thus holding converse only with myself and considering my own nature, I will try little by little to reach a better knowledge of and a more familiar acquaintanceship with myself. I am a thing that thinks, that is to say, that doubts, affirms, denies, that knows a few things, that is ignorant of many [that loves, that hates], that wills, that desires, that also imagines and perceives; for as I remarked before, although the things which I perceive and imagine are perhaps nothing at all apart from me and in themselves, I am nevertheless assured that these modes of thought that I call perceptions and imaginations, inasmuch only as they are modes of thought, certainly reside [and are met with] in me.

CLARITY AND DISTINCTNESS. Descartes notes that when he contemplates the certainty of his existence, he knows the truth of his existence clearly and distinctly.

            And in the little that I have just said, I think I have summed up all that I really know, or at least all that until now I was aware that I knew. In order to try to extend my knowledge further, I will now look around more carefully and see whether I cannot still discover in myself some other things which I have not until now perceived. I am certain that I am a thing which thinks. But do I not then likewise know what is requisite to render me certain of a truth? Certainly in this first knowledge there is nothing that assures me of its truth, except the clear and distinct perception of that which I state, which would not indeed suffice to assure me that what I say is true, if it could ever happen that a thing which I conceived so clearly and distinctly could be false; and accordingly it seems to me that already I can establish as a general rule that all things which I perceive very clearly and very distinctly are true.

(1) What is the general rule which Descartes posits regarding clarity and distinctness?

Certainty of the World and Mathematics. Descartes would like to use this general rule and show both the existence of external objects and the truth of mathematics. For, to differing degrees, both of these are vivid concepts. Unfortunately, knowledge of external objects does not rise to the level of clarity and distinctness.

            At the same time I have before received and admitted many things to be very certain and evident, which yet I afterwards recognized as being dubious. What then were these things? They were the earth, sky, stars and all other objects which I grasped by means of the senses. But what did I clearly [and distinctly] perceive in them? Nothing more than that the ideas or thoughts of these things were presented to my mind. And not even now do I deny that these ideas are met with in me. But there was yet another thing which I affirmed, and which, owing to the habit which I had formed of believing it, I thought I perceived very clearly, although in truth I did not perceive it at all, namely, that there were objects outside of me from which these ideas proceeded, and to which they were entirely similar. And it was in this that I erred, or, if perchance my judgment was correct, this was not due to any knowledge arising from my perception.

(2) What judgments about the external world at first seemed vivid, but later proved to be questionable?

By contrast, mathematical judgments are perceived clearly and distinctly.

            But when I took anything very simple and easy in the sphere of arithmetic or geometry into consideration, for example, that two and three together made five, and other things of the sort, were not these present to my mind so clearly as to enable me to affirm that they were true? Certainly if I judged that since such matters could be doubted, this would not have been so for any other reason than that it came into my mind that perhaps a God might have endowed me with such a nature that I may have been deceived even concerning things which seemed to me most evident. But every time that this preconceived opinion of the sovereign power of a God presents itself to my thought, I am constrained to confess that it is easy to Him, if he wishes it, to cause me to err, even in matters in which I believe myself to have the best evidence. And, on the other hand, always when I direct my attention to things which I believe myself to perceive very clearly, I am so persuaded of their truth that I let myself break out into words such as these: Let who will deceive me, he can never cause me to be nothing while I think that I am, or some day cause it to be true to say that I have never been, it being true now to say that I am, or that two and three make more or less than five, or any such thing in which I see a evident contradiction.

However, an obstacle remains: God may be deceiving him irrespective of how clearly and distinctly he perceives mathematical truths. To put the general rule of clarity and distinctness on sound footing, Descartes must (a) prove God’s existence, and then (b) show that God is not a deceiver.

And, certainly, since I have no reason to believe that there is a God who is a deceiver, and as I have not yet satisfied myself that there is a God at all, the reason for doubt which depends on this opinion alone is very slight, and so to speak metaphysical. But in order to be able altogether to remove it, I must inquire whether there is a God as soon as the occasion presents itself; and if I find that there is a God, I must also inquire whether he may be a deceiver. For without a knowledge of these two truths I do not see that I can ever be certain of anything.

            THOUGHTS AND IDEAS. In constructing his argument for God’s existence, Descartes makes several prefatory comments about the nature and content of human thought.

Classification of Thoughts. He begins outlining the various types of thoughts we have.

            And in order that I may have an opportunity of inquiring into this in an orderly way [without interrupting the order of meditation which I have proposed to myself, and which is little by little to pass from the notions which I find first of all in my mind to those which I will later on discover in it] it is requisite that I should here divide my thoughts into certain kinds, and that I should consider in which of these kinds there is, properly speaking, truth or error to be found. Of my thoughts some are, so to speak, images of the things, and to these alone is the title “idea” properly applied; examples are my thought of a man or of a chimera, of heaven, of an angel, or [even] of God. But other thoughts possess other forms as well. For example in willing, fearing, approving, denying, though I always perceive something as the subject of the action of my mind, yet by this action I always add something else to the idea which I have of that thing; and of the thoughts of this kind some are called volitions or affections, and others judgments.

(3) Name and give examples of the three classifications of thought.

            Now as to what concerns ideas, if we consider them only in themselves and do not relate them to anything else beyond themselves, they cannot properly speaking be false; for whether I imagine a goat or a chimera, it is not less true that I imagine the one that the other. We must not fear likewise that falsity can enter into will and into affections, for although I may desire evil things, or even things that never existed, it is not the less true that I desire them. Thus there remains no more than the judgments which we make, in which I must take the greatest care not to deceive myself. But the principal error and the most common which we may meet with in them, consists in my judging that the ideas which are in me are similar or conformable to the things which are outside me. For without doubt if I considered the ideas only as certain modes of my thoughts, without trying to relate them to anything beyond, they could scarcely give me material for error.

(4) Which of the three types of thought is responsible for decisions about truth and falsehood?

(5) What is the most frequent error found in judgments?

            But among these ideas, some appear to me to be innate, some adventitious, and others to be formed [or invented] by myself; for, as I have the power of understanding what is called a thing, or a truth, or a thought, it appears to me that I hold this power from no other source than my own nature. But if I now hear some sound, if I see the sun, or feel heat, I have until now judged that these sensations proceeded from certain things that exist outside of me; and finally it appears to me that sirens, hippogryphs, and the like, are formed out of my own mind. But again I may possibly persuade myself that all these ideas are of the nature of those which I term adventitious, or else that they are all innate, or all fictitious: for I have not yet clearly discovered their true origin.

(6) Name and describe the three kinds of ideas.

            Belief Concerning Adventitious Ideas. A final prefatory issue concerns the Adventitious ideas (that is, ideas of external objects). Are they really produced by external objects as they seem to be?

            And my principal task in this place is to consider, in respect to those ideas which appear to me to proceed from certain objects that are outside me, what are the reasons which cause me to think them similar to these objects. It seems indeed in the first place that I am taught this lesson by nature; and, secondly, I experience in myself that these ideas do not depend on my will nor therefore on myself for they often present themselves to my mind in spite of my will. Just now, for instance, whether I will or whether I do not will, I feel heat, and thus I persuade myself that this feeling, or at least this idea of heat, is produced in me by something which is different from me, that is, by the heat of the fire near which I sit. And nothing seems to me more obvious than to judge that this object imprints its likeness rather than anything else upon me.

One reason why we believe adventitious ideas have their origin in physical objects (as opposed to being mere fictions of the mind) is because we are taught this by nature.

            Now I must discover whether these proofs are sufficiently strong and convincing. When I say that I am so instructed by nature, I merely mean a certain spontaneous inclination which impels me to believe in this connection, and not a natural light which makes me recognize that it is true. But these two things are very different. For I cannot doubt that which the natural light causes me to believe to be true, as, for example, it has shown me that I am from the fact that I doubt, or other facts of the same kind. And I possess no other faculty whereby to distinguish truth from falsehood, which can teach me that what this light shows me to be true is not really true, and no other faculty that is equally trustworthy. But as far as [apparently] natural impulses are concerned, I have frequently remarked, when I had to make active choice between virtue and vice, that they often enough led me to the part that was worse. And this is why I do not see any reason for following them in what regards truth and error.

(7) What are the two senses in which we may be taught something by nature?

(8) Descartes believes that nature teaches us in an unabsolute sense (that is, by a spontaneous impulse) that adventitious ideas are caused by external objects. Why, though, can’t we trust natural impulses?

            And as to the other reason, which is that these ideas must proceed from objects outside me, since they do not depend on my will, I do not find it any the more convincing. For just as these impulses of which I have spoken are found in me, notwithstanding that they do not always agree with my will, so perhaps there is in me some faculty fitted to produce these ideas without the assistance of any external things, even though it is not yet known by me; just as, apparently, they have until now always been found in me during sleep without the aid of any external objects.

(9) Another reason why we believe adventitious ideas have their origin in external objects is that these ideas are independent of our will or volitions. Why may we not rely on this reason?

            And finally, though they did proceed from objects different from myself, it is not a necessary consequence that they should resemble these. On the contrary, I have noticed that in many cases there was a great difference between the object and its idea. I find, for example, two completely diverse ideas of the sun in my mind; the one derives its origin from the senses, and should be placed in the category of adventitious ideas; according to this idea the sun seems to be extremely small; but the other is derived from astronomical reasonings, that is, is elicited from certain notions that are innate in me, or else it is formed by me in some other manner; in accordance with it the sun appears to be several times greater than the earth. These two ideas cannot, indeed, both resemble the same sun, and reason makes me believe that the one which seems to have originated directly from the sun itself, is the one which is most dissimilar to it.

(10) Descartes next argues that even if adventitious ideas were caused by external objects, an idea may in no way resemble the object causing it. How does he illustrate this problem with our two ideas of the sun?

            All this causes me to believe that until the present time it has not been by a judgment that was certain [or premeditated], but only by a sort of blind impulse that I believed that things existed outside of, and different from me, which, by the organs of my senses, or by some other method whatever it might be, conveyed these ideas or images to me [and imprinted on me their likenesses].

Descartes concludes that only a “blind impulse” makes us believe that adventitious ideas correspond to real physical objects.

PROOF OF GOD’S EXISTENCE. Since adventitious ideas have no clear basis in external objects, then Descartes cannot attempt to prove God’s existence through a posteriori arguments (that is, arguments based on our perception of external objects). For example, he cannot argue for God’s existence based on apparent design in the world, since he cannot trust his adventitious ideas of design. However, there is another path open to him. He may simply examine the content of his ideas, ignoring their connection with external objects. In his words, he will consider his ideas as merely “modes of thought.”

            But there is yet another method of inquiring whether any of the objects of which I have ideas within me exist outside of me. If ideas are only taken as certain modes of thought, I recognize amongst them no difference or inequality, and all appear to proceed from me in the same manner; but when we consider them as images, one representing one thing and the other another, it is clear that they are very different one from the other. There is no doubt that those which represent to me substances are something more, and contain so to speak more objective reality within them [that is to say, by representation participate in a higher degree of being or perfection] than those that simply represent modes or accidents; and that idea again by which I understand a supreme God, eternal, infinite, [immutable], omniscient, omnipotent, and Creator of all things which are outside of Himself, has certainly more objective reality in itself than those ideas by which finite substances are represented.

When we view ideas merely as modes of thought, some seem more perfect or complex than others. In Descartes’ terminology, a more perfect or complex idea has greater objective reality than a less perfect or complex idea. For example, ideas of eternal substance, such as God, have more perfection than ideas of finite substance, such as trees or dogs.

Principle of Sufficient Reason. Descartes next discusses a principle of causality: “there must be as much in the total efficient cause as there is in the effect of that same cause.” In short, there must be as much in any cause as there is in its effect. This principle has been traditionally called the principle of sufficient reason.

            Now it is evident by the natural light that there must at least be as much reality in the efficient and total cause as in its effect. For, I ask, from where can the effect derive its reality, if not from its cause? And in what way can this cause communicate this reality to it, unless it possessed it in itself? And from this it follows, not only that something cannot proceed from nothing, but likewise that what is more perfect that is to say, which has more reality within itself cannot proceed from the less perfect.

(11) How does Descartes know the truth of his principle of sufficient reason?

(12) What are two consequences which follow from the principle of sufficient reason?

Descartes argues that the principle of sufficient reason applies to ideas as well as to physical objects. That is, an idea with a moderate amount of objective reality (let’s say, with five units of complexity) must be produced by something with at least that much objective reality (five or more units of complexity).

And this is not only evidently true of those effects which possess actual or formal reality, but also of the ideas in which we consider merely what is termed objective reality. To take an example, the stone which has not yet existed not only cannot now commence to be unless it has been produced by something which possesses within itself, either formally or eminently, all that enters into the composition of the stone [that is, it must possess the same things or other more excellent things than those which exist in the stone] and heat can only be produced in a subject in which it did not previously exist by a cause that is of an order [degree or kind] at least as perfect as heat, and so in all other cases.

(13) How does the principle of sufficient reason apply to the causes of an actual stone or some actual heat?

But further, the idea of heat, or of a stone, cannot exist in me unless it has been placed within me by some cause which possesses within it at least as much reality as that which I conceive to exist in the heat or the stone. For although this cause does not transmit anything of its actual or formal reality to my idea, we must not for that reason imagine that it is necessarily a less real cause; we must remember that [since every idea is a work of the mind] its nature is such that it demands of itself no other formal reality than that which it borrows from my thought, of which it is only a mode [that is, a manner or way of thinking]. But in order that an idea should contain some one certain objective reality rather than another, it must without doubt derive it from some cause in which there is at least as much formal reality as this idea contains of objective reality. For if we imagine that something is found in an idea which is not found in the cause, it must then have been derived from nothing; but however imperfect may be this mode of being by which a thing is objectively [or by representation] in the understanding by its idea, we cannot certainly say that this mode of being is nothing, nor consequently, that the idea derives its origin from nothing.

(14) How does the principle of sufficient reason apply to the causes of our ideas of heat or of a stone?

            Nor must I imagine that, since the reality that I consider in these ideas is only objective, it is not essential that this reality should be formally in the causes of my ideas, but that it is sufficient that it should be found objectively. For just as this mode of objective existence pertains to ideas by their proper nature, so does the mode of formal existence pertain tot he causes of those ideas (this is at least true of the first and principal) by the nature peculiar to them. And although it may be the case that one idea gives birth to another idea, that cannot continue to be so indefinitely; for in the end we must reach an idea whose cause will be so to speak an archetype, in which the whole reality [or perfection] which is so to speak objectively [or by representation] in these ideas is contained formally [and really]. Thus the light of nature causes me to know clearly that the ideas in me are like [pictures or] images which can, in truth, easily fall short of the perfection of the objects from which they have been derived, but which can never contain anything greater or more perfect.

(15) Descartes argues that the causes of our ideas cannot be explained by an infinite regress other ideas. What sort of first idea must be reached?

            And the longer and the more carefully that I investigate these matters, the more clearly and distinctly do I recognize their truth. But what am I to conclude from it all in the end? It is this, that if the objective reality of any one of my ideas is of such a nature as clearly to make me recognize that it is not in me either formally or eminently, and that consequently I cannot myself be the cause of it, it follows of necessity that I am not alone in the world, but that there is another being which exists, or which is the cause of this idea. On the other hand, had no such an idea existed in me, I should have had no sufficient argument to convince me of the existence of any being beyond myself; for I have made very careful investigation everywhere and up to the present time have been able to find no other ground.

(16)      Suppose Descartes came across an idea in his mind which contained more objective reality than he alone could cause. What would necessary follow from this?

Origin of our Various Ideas. Based on the principle of sufficient reason as it applies to ideas, Descartes believes that there are important conclusions we can draw about the origin of specific ideas.

            But of my ideas, beyond that which represents me to myself, as to which there can here be no difficulty, there is another which represents a God, and there are others representing corporeal and inanimate things, others angels, others animals, and others again which represent to me men similar to myself.

            As regards the ideas which represent to me other men or animals, or angels, I can however easily conceive that they might be formed by an admixture of the other ideas which I have of myself, of corporeal things, and of God, even although there were apart from me neither men nor animals, nor angels, in all the world.

(17) Why does Descartes believe that his ideas of people, animals or angels could have arisen from within himself?

Descartes continues discussing the origins of ideas of physical objects, particularly regarding their secondary and primary qualities.

            And in regard to the ideas of corporeal objects, I do not recognize in them anything so great or so excellent that they might not have possibly proceeded from myself; for if I consider them more closely, and examine them individually, as I yesterday examined the idea of wax, I find that there is very little in them which I perceive clearly and distinctly. Magnitude or extension in length, breadth, or depth, I do so perceive; also figure which results from a termination of this extension, the situation which bodies of different figure preserve in relation to one another, and movement or change of situation; to which we may also add substance, duration and number. As to other things such as light, colors, sounds, scents, tastes, heat, cold and the other tactile qualities, they are thought by me with so much obscurity and confusion that I do not even know if they are true or false, that is, whether the ideas which I form of these qualities are actually the ideas of real objects or not [or whether they only represent chimeras which cannot exist in fact]. For although I have before remarked that it is only in judgments that falsity, properly speaking, or formal falsity, can be met with, a certain material falsity may nevertheless be found in ideas, that is, when these ideas represent what is nothing as though it were something. For example, the ideas which I have of cold and heat are so far from clear and distinct that by their means I cannot tell whether cold is merely an absence of heat, or heat an absence of cold, or whether both are real qualities, or are not such. And inasmuch as [since ideas resemble images] there cannot be any ideas which do not appear to represent some things, if it is correct to say that cold is merely an absence of heat, the idea which represents it to me as something real and positive will not be improperly termed false, and the same holds good of other similar ideas.

            To these it is certainly not necessary that I should attribute any author other than myself. For if they are false, that is, if they represent things which do not exist, the light of nature shows me that they issue from nothing, that is to say, that they are only in me so far as something is lacking to the perfection of my nature. But if they are true, nevertheless because they exhibit so little reality to me that I cannot even clearly distinguish the thing represented from non-being, I do not see any reason why they should not be produced by myself.

(18) Why does Descartes believe that his ideas of light, colors, sounds, odors, tastes, and heat (that is, secondary qualities) need no explanation outside of himself?

Descartes next draws conclusions about the possible origins of our ideas of primary qualities.

            As to the clear and distinct idea which I have of corporeal things, some of them seem as though I might have derived them from the idea which I possess of myself, as those which I have of substance, duration, number, and such like. For [even] when I think that a stone is a substance, or at least a thing capable of existing of itself, and that I am a substance also, although I conceive that I am a thing that thinks and not one that is extended, and that the stone on the other hand is an extended thing which does not think, and that thus there is a notable difference between the two conceptions they seem, nevertheless, to agree in this, that both represent substances. In the same way, when I perceive that I now exist and further recollect that I have in former times existed, and when I remember that I have various thoughts of which I can recognize the number, I acquire ideas of duration and number which I can afterwards transfer to any object that I please. But as to all the other qualities of which the ideas of corporeal things are composed, namely, extension, figure, situation and motion, it is true that they are not formally in me, since I am only a thing that thinks. But because they are merely certain modes of substance [and so to speak the vestments under which corporeal substance appears to us] and because I myself am also a substance, it would seem that they might be contained in me eminently.

(19) Descartes also argues that primary qualities, such as substance, duration, and number, may also be explained by the idea of himself. When substance is defined as an aptitude for existing, how might he arrive at the idea of substance by himself?

(20) How might he acquire the ideas of duration and number?

Origin of the Idea of Infinite Perfection. Finally, Descartes considers the idea of God which is in his mind. This idea is that of “an infinite and independent substance.” More to the point, he has in his mind an idea of infinite perfection.

            Hence there remains only the idea of God, concerning which we must consider whether it is something which cannot have proceeded from me myself. By the name God I understand a substance that is infinite [eternal, immutable], independent, all-knowing, all-powerful, and by which I myself and everything else, if anything else does exist, have been created. Now all these characteristics are such that the more diligently I attend to them, the less do they appear capable of proceeding from me alone; hence, from what has been already said, we must conclude that God necessarily exists.

(21) Since Descartes’ idea of infinite perfection could not have been produced by himself, what must he conclude?

Formally, Descartes’ argument for God’s existence is as follows:

            (a) We have an idea of infinite perfection.

            (b) The idea we have of ourselves entails finitude and imperfection.

            (c) There must be as much reality in the cause of any idea as in the idea itself (the principle of sufficient reason).

            (e) Therefore, the idea we have of infinite perfection originated from a being with infinite perfection, and this being is God.

REPLIES TO POSSIBLE CRITICISMS. Once proving God’s existence, Descartes addresses three possible criticisms of his proof. Each of these possible criticisms suggests that our idea of infinite perfection need not be caused by God himself.

Perhaps the Finite is a Negation of the Infinite. A first possible criticism is based on Descartes assumption that we initially possess an idea of the infinite, and that our idea of the finite consists of the negation of our idea of the infinite. A critic might argue that the opposite is the case: we have an initial idea of the finite and our idea of the infinite is its negation. In this case, we could be the cause of infinite perfection by (a) taking the idea of finite imperfection from ourselves, and (b) negating this idea. Thus, for Descartes’ proof to be successful, he needs to show that we initially possess an idea of the infinite.

            For although the idea of substance is within me owing to the fact that I am substance, nevertheless I should not have the idea of an infinite substance since I am finite if it had not proceeded from some substance which was truly infinite.

            Nor should I imagine that I do not perceive the infinite by a true idea, but only by the negation of the finite, just as I perceive calmness and darkness by the negation of movement and of light; for, on the contrary, I see that there is evidently more reality in infinite substance than in finite, and therefore that in some way I have in me the notion of the infinite earlier then the finite namely, the notion of God before that of myself. For how would it be possible that I should know that I doubt and desire, that is to say, that something is lacking to me, and that I am not quite perfect, unless I had within me some idea of a Being more perfect than myself, in comparison with which I should recognize the deficiencies of my nature?

(22) How does Descartes know that we initially possess an idea of the infinite?

Perhaps the Idea of Infinite Perfection came from Nothing. A second possible criticism is that the idea of infinite perfection is “materially false and can therefore be from nothing.” More simply, the suggestion is that the idea of infinite perfection is an incoherent concept, and needs no explanation beyond itself.

            And we cannot say that this idea of God is perhaps materially false and that consequently I can derive it from nothing [that is, that possibly it exists in me because I am imperfect], as I have just said is the case with ideas of heat, cold and other such things; for, on the contrary, as this idea is very clear and distinct and contains within it more objective reality than any other, there can be none which is of itself more true, nor any in which there can be less suspicion of falsehood. The idea, I say, of this Being who is absolutely perfect and infinite, is entirely true; for although, perhaps, we can imagine that such a Being does not exist, we cannot nevertheless imagine that his idea represents nothing real to me, as I have said of the idea of cold. This idea is also very clear and distinct; since all that I conceive clearly and distinctly of the real and the true, and of what conveys some perfection, is in its entirety contained in this idea. And this does not cease to be true although I do not comprehend the infinite, or though in God there is an infinitude of things which I cannot comprehend, nor possibly even reach in any way by thought; for it is of the nature of the infinite that my nature, which is finite and limited, should not comprehend it; and it is sufficient that I should understand this, and that I should judge that all things which I clearly perceive and in which I know that there is some perfection, and possibly likewise an infinitude of properties of which I am ignorant, are in God formally or eminently, so that the idea which I have of Him may become the most true, most clear, and most distinct of all the ideas that are in my mind.

(23) What is Descartes’ reply to the criticism that the idea of infinite perfection came from nothing?

Perhaps I am Potentially Infinitely Perfect. A third possible criticism is that perhaps we are potentially infinitely perfect, and thus produced the idea of infinite perfection from our hidden potential.

            But possibly I am something more than I suppose myself to be, and perhaps all those perfections which I attribute to God are in some way potentially in me, although they do not yet disclose themselves, or issue in action. As a matter of fact I am already sensible that my knowledge increases [and perfects itself] little by little, and I see nothing which can prevent it from increasing more and more into infinitude; nor do I see, after it has thus been increased [or perfected], anything to prevent my being able to acquire by its means all the other perfections of the Divine nature; nor finally why the power I have of acquiring these perfections, if it really exists in me, will not suffice to produce the ideas of them.

Descartes gives three replies to this third criticism. First, if his potential perfection can be actualized only gradually (through a gradual increase in knowledge), this implies that he is finite. And, if he is a finite being, he could not produce the idea of infinite perfection. Second, he argues that even if his knowledge would increase gradually over an infinite amount of time, at no point would he have infinite knowledge.

            At the same time I recognize that this cannot be. For, in the first place, although it were true that every day my knowledge acquired new degrees of perfection, and that there were in my nature many things potentially which are not yet there actually, nevertheless these excellences do not pertain to [or make the smallest approach to] the idea which I have of God in whom there is nothing merely potential [but in whom all is present really and actually]; for it is an infallible token of imperfection in my knowledge that it increases little by little. and further, although my knowledge grows more and more, nevertheless I do not for that reason believe that it can ever be actually infinite, since it can never reach a point so high that it will be unable to attain to any greater increase. But I understand God to be actually infinite, so that he can add nothing to his supreme perfection. And finally I perceive that the objective being of an idea cannot be produced by a being that exists potentially only, which properly speaking is nothing, but only by a being which is formal or actual.

(24) What is his third and final reply to the above criticism?

THE SOURCE OF MY EXISTENCE. Since Descartes has proven his own existence and the existence of God, he now finds it appropriate to show that God was the cause of his existence. He shows this through the process of elimination, arguing that he could not be produced by (a) himself, (b) a finite cause less perfect than God, (c) by several partial causes, or (d) by his parents. God is the only possible cause for his existence.

            To speak the truth, I see nothing in all that I have just said which by the light of nature is not evident to anyone who desires to think attentively on the subject; but when I slightly relax my attention, my mind, finding its vision somewhat obscured and so to speak blinded by the images of sensible objects, I do not easily recollect the reason why the idea that I possess of a being more perfect then I, must necessarily have been placed in me by a being which is really more perfect; and this is why I wish here to go on to inquire whether I, who have this idea, can exist if no such being exists.

            And I ask, from whom do I then derive my existence? Perhaps from myself or from my parents, or from some other source less perfect than God; for we can imagine nothing more perfect than God, or even as perfect as he is.

Perhaps I Caused my Existence. Descartes first considers whether he is the cause of his own existence.

            But [were I independent of every other and] were I myself the author of my being, I should doubt nothing and I should desire nothing, and finally no perfection would be lacking to me; for I should have bestowed on myself every perfection of which I possessed any idea and should thus be God. And it must not be imagined that those things that are lacking to me are perhaps more difficult of attainment than those which I already possess; for, on the contrary, it is quite evident that it was a matter of much greater difficulty to bring to pass that I, that is to say, a thing or a substance that thinks, should emerge out of nothing, than it would be to attain to the knowledge of many things of which I am ignorant, and which are only the accidents of this thinking substance. But it is clear that if I had of myself possessed this greater perfection of which I have just spoken [that is to say, if I had been the author of my own existence], I should not at least have denied myself the things which are the more easy to acquire [namely, many branches of knowledge of which my nature is destitute]; nor should I have deprived myself of any of the things contained in the idea which I form of God, because there are none of them which seem to me specially difficult to acquire: and if there were any that were more difficult to acquire, they would certainly appear to me to be such (supposing I myself were the origin of the other things which I possess) since I should discover in them that my powers were limited.

(25) Descartes gives two replies to the suggestion that he was derived from himself. His first reply is that if he caused himself, then he would be God. Why is this?

            But though I assume that perhaps I have always existed just as I am at present, neither can I escape the force of this reasoning, and imagine that the conclusion to be drawn from this is, that I need not seek for any author of my existence. For all the course of my life may be divided into an infinite number of parts, none of which is in any way dependent on the other; and thus from the fact that I was in existence a short time ago it does not follow that I must be in existence now, unless some cause at this instant, so to speak, produces me anew, that is to say, conserves me. It is as a matter of fact perfectly clear and evident to all those who consider with attention the nature of time, that, in order to be conserved in each moment in which it endures, a substance has need of the same power and action as would be necessary to produce and create it anew, supposing it did not yet exist, so that the light of nature shows us clearly that the distinction between creation and conservation is solely a distinction of the reason.

            All that I thus require here is that I should interrogate myself, if I wish to know whether I possess a power which is capable of bringing it to pass that I who now am will still be in the future; for since I am nothing but a thinking thing, or at least since thus far it is only this portion of myself which is precisely in question at present, if such a power did reside in me, I should certainly be conscious of it. But I am conscious of nothing of the kind, and by this I know clearly that I depend on some being different from myself.

(26) Descartes’ second reply is based on the fact that he exists over time. Each of the parts and moments of his existence depends on others. He then asks whether “I have some power through which I can bring it about that I myself, who now am, will also exist a little later?” What is his answer?

Perhaps a Finite Cause Created Me. Another suggestion is that he was caused by a finite cause less perfect than God. He responds noting that this finite cause would have to possess the idea of infinite perfection too, hence we need to inquire into its cause as well.

            Possibly, however, this being on which I depend is not that which I call God, and I am created either by my parents or by some other cause less perfect than God. This cannot be, because, as I have just said, it is perfectly evident that there must be at least as much reality in the cause as in the effect; and thus since I am a thinking thing, and possess an idea of God within me, whatever in the end be the cause assigned to my existence, it must be allowed that it is likewise a thinking thing and that it possesses in itself the idea of all the perfections which I attribute to God. We may again inquire whether this cause derives its origin from itself or from some other thing. For if from itself, it follows by the reasons before brought forward, that this cause must itself be God; for since it possesses the virtue of self-existence, it must also without doubt have the power of actually possessing all the perfections of which it has the idea, that is, all those which I conceive as existing in God. But if it derives its existence from some other cause than itself, we will again ask, for the same reason, whether this second cause exists by itself or through another, until from one step to another, we finally arrive at an ultimate cause, which will be God.

            And it is perfectly evident that in this there can be no regression into infinity, since what is in question is not so much the cause which formerly created me, as that which conserves me at the present time.

(27) Why can’t there be an infinite regress of such finite causes?

Perhaps Several Partial Causes Created Me. Another suggestion is that he was created by several partial causes.

            Nor can we suppose that several causes may have collaborated in my production, and that from one I have received the idea of one of the perfections which I attribute to God, and from another the idea of some other, so that all these perfections indeed exist somewhere in the universe, but not as complete in one unity which is God. On the contrary, the unity, the simplicity or the inseparability of all things which are in god is one of the principal perfections which I conceive to be in Him. And certainly the idea of this unity of all Divine perfections cannot have been placed in me by any cause from which I have not likewise received the ideas of all the other perfections; for this cause could not make me able to comprehend them as joined together in an inseparable unity without having at the same time caused me in some measure to know what they are [and in some way to recognize each one of them].

(28) What is wrong with this suggestion that he was created by several partial causes?

Perhaps my Parents Created Me. Finally, he addresses the suggestion that he was caused by his parents.

            Finally, so far as my parents [from whom it appears I have sprung] are concerned, although all that I have ever been able to believe of them were true, that does not make it follow that it is they who conserve me, nor are they even the authors of my being in any sense, in so far as I am a thinking being; since what they did was merely to implant certain dispositions in that matter in which the self that is, the mind, which alone I at present identify with myself is by me deemed to exist. And thus there can be no difficulty in their regard, but we must of necessity conclude from the fact alone that I exist, or that the idea of a Being supremely perfect that is of God is in me, that the proof of God’s existence is grounded on the highest evidence.

(29) Although his parents may be the cause of his body, in what two respects could they not be his cause?

God the is the Cause of Me. Descartes concludes that God must be the cause of him, and that God innately implanted the idea of infinite perfection in him.

            It only remains to me to examine into the manner in which I have acquired this idea from God; for I have not received it through the senses, and it is never presented to me unexpectedly, as is usual with the ideas of sensible things when these things present themselves, or seem to present themselves, to the external organs of my senses; nor is it likewise a fiction of my mind, for it is not in my power to take from or to add anything to it; and consequently the only alternative is that it is innate in me, just as the idea of myself is innate in me.

GOD IS NOT A DECEIVER. Descartes closes Meditation Three arguing that God is not a deceiver.

            And one certainly ought not to find it strange that God, in creating me, placed this idea within me to be like the mark of the workman imprinted on his work; and it is likewise not essential that the mark will be something different from the work itself. For from the sole fact that God created me it is most probable that in some way he has placed his image and likeness upon me, and that I perceive this likeness (in which the idea of God is contained) by means of the same faculty by which I perceive myself.  That is to say, when I reflect on myself I not only know that I am something [imperfect], incomplete and dependent on another, which incessantly aspires after something which is better and greater than myself, but I also know that he on whom I depend possesses in Himself all the great things towards which I aspire [and the ideas of which I find within myself]. And he possesses this not indefinitely or potentially alone, but really, actually and infinitely; and that thus he is God. And the whole strength of the argument which I have here made use of to prove the existence of God consists in this, that I recognize that it is not possible that my nature should be what it is, and indeed that I should have in myself the idea of a God -- if God did not truly exist a God, I say, whose idea is in me, that is, who possesses all those supreme perfections of which our mind may indeed have some idea but without understanding them all, who is liable to no errors or defect [and who has none of all those marks which denote imperfection]. From this it is evident that he cannot be a deceiver, since the light of nature teaches us that fraud and deception necessarily proceed from some defect.

(30) When focusing on God’s nature, why does he conclude that God is not a deceiver?

            But before I examine this matter with more care, and pass on to the consideration of other truths which may be derived from it, it seems to me right to pause for a while in order to contemplate God Himself, to ponder at leisure his marvelous attributes, to consider, and admire, and adore, the beauty of this light so resplendent, at least as far as the strength of my mind, which is in some measure dazzled by the sight, will allow me to do so. For just as faith teaches us that the supreme felicity of the other life consists only in this contemplation of the Divine Majesty, so we continue to learn by experience that a similar meditation, though incomparably less perfect, causes us to enjoy the greatest satisfaction of which we are capable in this life.

SYNOPSIS. Descartes’ synopsis of the Third Meditation (initially presented at the opening of his Meditations) is as follows.

            In the third Meditation it seems to me that I have explained at sufficient length the principal argument of which I make use in order to prove the existence of God. But none the less, because I did not wish in that place to make use of any comparisons derived from corporeal things, so as to withdraw as much as I could the minds of readers from the senses, there may perhaps have remained many obscurities which, however, will, I hope, be entirely removed by the Replies which I have made to the Objections which have been set before me. Amongst others there is, for example, this one, “How the idea in us of a being supremely perfect possesses so much objective reality [that is to say participates by representation in so many degrees of being and perfection] that it necessarily proceeds from a cause which is absolutely perfect.” This is illustrated in these Replies by the comparison of a very perfect machine, the idea of which is found in the mind of some workman. For as the objective contrivance of this idea must have some cause, that is, either the science of the workman or that of some other from whom he has received the idea, it is similarly impossible that the idea of God which is in us should not have God himself as its cause.

E. MEDITATION IV:

OF THE TRUE AND THE FALSE

At the close of the Third Meditation, Descartes has arrived at all of the fundamental principles he needs in his quest for truth: (1) he exists (a foundational fact which is indubitable), (2) God exists and is not a deceiver, and (3) clarity and distinctness are reliable indicators of truth. Descartes’ goal is to show that we can rely on our senses to at least some degree. Meditations IV and V do not contribute directly to this goal. Meditation IV explains the source of human error and argues that God is not responsible for our mistakes. Descartes’ concept of “error” is broad, referring to any mistaken judgment whatever. This includes assertions, predictions, ethical judgments, or judgments leading to an action.

SEVERAL WRONG THEORIES. Descartes begins his quest for the origin of error by considering several theories which he ultimately rejects.

Perhaps God is the Cause of my Error. Descartes first considers whether God could be the cause of his error.

I have been well accustomed these past days to detach my mind from my senses, and I have accurately observed that there are very few things that one knows with certainty respecting corporeal objects, that there are many more which are known to us respecting the human mind, and yet more still regarding God Himself; so that I will now without any difficulty abstract my thoughts from the consideration of [sensible or] imaginable objects, and carry them to those which, being withdrawn from all contact with matter, are purely intelligible. And certainly the idea which I possess of the human mind inasmuch as it is a thinking thing, and not extended in length, width and depth, nor participating in anything pertaining to body, is incomparably more distinct than is the idea of any corporeal thing. And when I consider that I doubt, that is to say, that I am an incomplete and dependent being, the idea of a being that is complete and independent, that is of God, presents itself to my mind with so much distinctness and clearness -- and from the fact alone that this idea is found in me, or that I who possess this idea exist, I conclude so certainly that God exists, and that my existence depends entirely on Him in every moment of my life -- that I do not think that the human mind is capable of knowing anything with more evidence and certitude. And it seems to me that I now have before me a road which will lead us from the contemplation of the true God (in whom all the treasures of science and wisdom are contained) to the knowledge of the other objects of the universe.

            For, first of all, I recognize it to be impossible that he should ever deceive me; for in all fraud and deception some imperfection is to be found, and although it may appear that the power of deception is a mark of subtlety or power, yet the desire to deceive without doubt testifies to malice or feebleness, and accordingly cannot be found in God.

(1) Why does Descartes reject the view that God is the source of error?

Perhaps Error Results from an Imperfect Faculty of Judgment. Descartes considers the possibility that human error results from his faculty of judgment. This makes sense since he sees himself as finite, existing on a middle rung of the great chain of being between God and nothing. Thus, error would seem to be a defect which we can blame on our faculty of judgment.

            In the next place I experienced in myself a certain capacity for judging which I have doubtless received from God, like all the other things that I possess; and as he could not desire to deceive me, it is clear that he has not given me a faculty that will lead me to err if I use it aright.

            And no doubt respecting this matter could remain, if it were not that the consequence would seem to follow that I can thus never be deceived; for if I hold all that I possess from God, and if he has not placed in me the capacity for error, it seems as though I could never fall into error. And it is true that when I think only of God [and direct my mind wholly to Him], I discover [in myself] no cause of error, or falsity; yet directly afterwards, when recurring to myself, experience shows me that I am nevertheless subject to an infinitude of errors, as to which, when we come to investigate them more closely, I notice that not only is there a real and positive idea of God or of a Being of supreme perfection present to my mind, but also, so to speak, a certain negative idea of nothing, that is, of that which is infinitely removed from any kind of perfection; and that I am in a sense something intermediate between God and nothing, that is, placed in such a manner between the supreme Being and non-being, that there is in truth nothing in me that can lead to error in so far as a sovereign Being has formed me; but that, as I in some degree participate likewise in nothing or in non-being, that is, in so far as I am not myself the supreme Being, and as I find myself subject to an infinitude of imperfections, I ought not to be astonished if I should fall into error. Thus do I recognize that error, in so far as it is such, is not a real thing depending on God, but simply a defect. And therefore, in order to fall into it, that I have no need to possess a special faculty given me by God for this very purpose, but that I fall into error from the fact that the power given me by God for the purpose of distinguishing truth from error is not infinite.

            Nevertheless this does not quite satisfy me. For error is not a pure negation [that is, is not the dimple defect or want of some perfection which ought not to be mine], but it is a lack of some knowledge which it seems that I ought to possess. And on considering the nature of God it does not appear to me possible that he should have given me a faculty which is not perfect of its kind, that is, which is wanting in some perfection due to it. For if it is true that the more skillful the artisan, the more perfect is the work of his hands, what can have been produced by this supreme Creator of all things that is not in all its parts perfect? And certainly there is no doubt that God could have created me so that I could never have been subject to error. It is also certain that he always wills what is best. Is it then better that I should be subject to err than that I should not?

(2) Why is it unsatisfactory to say that human error results from his faculty of judgment?

Perhaps the Source of Error is Inexplicable. Descartes is puzzled that God could have made him such that he would never err, yet he clearly does err. Descartes suggests that maybe he can never know God’s purpose in allowing us to err, since the wisdom of God is above human intellect.

            In considering this more attentively, it occurs to me in the first place that I should not be astonished if my intelligence is not capable of comprehending why God acts as he does; and that there is thus no reason to doubt of his existence from the fact that I may perhaps find many other things besides this as to which I am able to understand neither for what reason nor how God has produced them. For, in the first place, knowing that my nature is extremely feeble and limited, and that the nature of God is on the contrary immense, incomprehensible, and infinite, I have no further difficulty in recognizing that there is an infinitude of matter in his power, the causes of which transcend my knowledge. And this reason suffices to convince me that the species of cause termed final, finds no useful employment in physical [or natural] things. For it does not appear to me that I can without temerity seek to investigate the [inscrutable] ends of God.

            It further occurs to me that we should not consider one single creature separately, when we inquire as to whether the works of God are perfect, but should regard all his creations together. For the same thing which might possibly seem very imperfect with some semblance of reason if regarded by itself, is found to be very perfect if regarded as part of the whole universe. And although, since I resolved to doubt all things, I as yet have only known certainly my own existence and that of God, nevertheless since I have recognized the infinite power of God, I cannot deny that he may have produced many other things, or at least that he has the power of producing them, so that I may obtain a place as a part of a great universe.

(3) Rather than examining God’s purpose in allowing him personally (as one creature) to err, how should this be viewed?

FACULTIES OF THE UNDERSTANDING AND THE WILL. After rejecting the above suggestions, Descartes considers the specific faculties involved when we make mistakes.

            Whereupon, regarding myself more closely, and considering what are my errors (for they alone testify to there being any imperfection in me), I answer that they depend on a combination of two causes, namely, on the faculty of knowledge that rests in me, and on the power of choice or of free will -- that is to say, of the understanding and at the same time of the will.

(4) What are the two mental faculties involved when we fall into error?

Perhaps the Understanding causes Error. Descartes can find no reason to hold either of these faculties individually responsible for error. He begins by looking at the understanding.

For by the understanding alone I [neither assert nor deny anything, but] mean the ideas of things as to which I can form a judgment. But no error is properly speaking found in it, provided the word error is taken in its proper meaning. And though there is possibly an infinitude of things in the world of which I have no idea in my understanding, we cannot for all that say that it is deprived of these ideas [as we might say of something which is required by its nature], but simply it does not possess these; because in truth there is no reason to prove that God should have given me a greater faculty of knowledge than he has given me. And however skillful a workman I represent Him to be, I should not for all that consider that he was bound to have placed in each of his works all the perfections which he may have been able to place in some.

(5) Why does he find no fault exclusively with the faculty of understanding (or reason) in producing error?

Perhaps the Will is Responsible for Error. Descartes next considers the will alone.

I likewise cannot complain that God has not given me a free choice or a will which is sufficient, ample and perfect, since as a matter of fact I am conscious of a will so extended as to be subject to no limits. And what seems to me very remarkable in this regard is that of all the qualities which I possess there is no one so perfect and so comprehensive that I do not very clearly recognize that it might be yet greater and more perfect. For, to take an example, if I consider the faculty of comprehension which I possess, I find that it is of very small extent and extremely limited, and at the same time I find the idea of another faculty much more ample and even infinite, and seeing that I can form the idea of it, I recognize from this very fact that it pertains to the nature of God. If in the same way I examine the memory, the imagination, or some other faculty, I do not find any which is not small and circumscribed, while in God it is immense [or infinite]. It is free-will alone or liberty of choice which I find to be so great in me that I can conceive no other idea to be more great; it is indeed the case that it is for the most part this will that causes me to know that in some manner I bear the image and likeness of God. For although the power of will is incomparably greater in God than in me, both by reason of the knowledge and the power which, conjoined with it, render it stronger and more efficacious, and by reason of its object, inasmuch as in God it extends to a great many things; it nevertheless does not seem to me greater if I consider it formally and precisely in itself: for the faculty of will consists alone in our having the power of choosing to do a thing or choosing not to do it (that is, to affirm or deny, to pursue or to shun it), or rather it consists alone in the fact that in order to affirm or deny, pursue or shun those things placed before us by the understanding, we act so that we are unconscious that any outside force constrains us in doing so.

(6) Why is no fault to be found with the faculty of the will in the production of error?

(7) Why is the will of a human as perfect as God’s will?

Descartes briefly discusses the free nature of our will.

For in order that I should be free it is not necessary that I should be indifferent as to the choice of one or the other of two contraries; but contrariwise the more I lean to the one -- whether I recognize clearly that the reasons of the good and true are to be found in it, or whether God so disposes my inward thought -- the more freely do I choose and embrace it. And undoubtedly both divine grace and natural knowledge, far from diminishing my liberty, rather increase it and strengthen it. Hence this indifference which I feel, when I am not swayed to one side rather than to the other by lack of reason, is the lowest grade of liberty, and rather evinces a lack or negation in knowledge than a perfection of will: for if I always recognized clearly what was true and good, I should never have trouble in deliberating as to what judgment or choice I should make, and then I should be entirely free without ever being indifferent.

(8) Descartes notes that even when strong motives incline us toward one direction, we choose all the more freely in that direction. What does he consider the lowest level of freedom?

Extending the Will Beyond our Knowledge. Descartes considers a final view that error results when we extend our will beyond our knowledge.

            From all this I recognize that the power of will which I have received from God is not of itself the source of my errors -- for it is very ample and very perfect of its kind -- any more than is the power of understanding; for since I understand nothing but by the power which God has given me for understanding, there is no doubt that all that I understand, I understand as I ought, and it is not possible that I err in this. Whence then come my errors? They come from the sole fact that since the will is much wider in its range and compass than the understanding, I do not restrain it within the same bounds, but extend it also to things which I do not understand: and as the will is of itself indifferent to these, it easily falls into error and sin, and chooses the evil for the good, or the false for the true.

(9) What is the ultimate source of our errors?

THE PROPER USE OF THE WILL. According to Descartes, our will often becomes indifferent (or lazy) and accidentally extends beyond the bounds of our knowledge. He stresses that we should abstain from willing when we have insufficient knowledge. As an example, he explains that at this stage in his investigation he doesn’t know whether his essential qualities include mind, body, or both. Hence, he abstains from any willful judgment on this issue. In this and similar cases, he believes that proper use of freedom requires us to abstain from willful judgment.

            For example, when I lately examined whether anything existed in the world, and found that from the very fact that I considered this question it followed very clearly that I myself existed, I could not prevent myself from believing that a thing I so clearly conceived was true: not that I found myself compelled to do so by some external cause, but simply because from great clearness in my mind there followed a great inclination of my will; and I believed this with so much the greater freedom or spontaneity as I possessed the less indifference towards it. Now, on the contrary, I not only know that I exist, inasmuch as I am a thinking thing, but a certain representation of corporeal nature is also presented to my mind. And it comes to pass that I doubt whether this thinking nature which is in me, or rather by which I am what I am, differs from this corporeal nature, or whether both are not simply the same thing. And I here suppose that I do not yet know any reason to persuade me to adopt the one belief rather than the other. From this it follows that I am entirely indifferent as to which of the two I affirm or deny, or even whether I abstain from forming any judgment in the matter.

            And this indifference does not only extend to matters as to which the understanding has no knowledge, but also in general to all those which are not grasped with perfect clearness at the moment when the will is deliberating upon them. For, however probable are the conjectures which render me disposed to form a judgment respecting anything, the simple knowledge that I have that those are conjectures alone and not certain and indubitable reasons, suffices to occasion me to judge the contrary. Of this I have had great experience of late when I set aside as false all that I had formerly held to be absolutely true, for the sole reason that I remarked that it might in some measure be doubted.

Descartes considers that, by chance, we sometimes stumble upon some truth beyond the scope of our knowledge.

            But if I abstain from giving my judgment on anything when I do not perceive it with sufficient clearness and distinctness, it is plain that I act rightly and am not deceived. But if I determine to deny or affirm, I no longer make use as I should of my free will, and if I affirm what is not true, it is evident that I deceive myself; even though I judge according to truth, this comes about only by chance, and I do not escape the blame of misusing my freedom. For the light of nature teaches us that the knowledge of the understanding should always precede the determination of the will. And it is in the misuse of the free will that the privation which constitutes the characteristic nature of error is met with. Privation, I say, is found in the act, in so far as it proceeds from me, but it is not found in the faculty which I have received from God, nor even in the act in so far as it depends on Him.

(10) Why does Descartes believes it is improper to use the will to accidentally discover truths?

GOD IS NOT RESPONSIBLE. Descartes next argues that even though God created us, God is not responsible for errors that we make. He considers several possible criticisms against God’s role. One might first criticize God for giving us limited knowledge.

            For I have certainly no cause to complain that God has not given me an intelligence which is more powerful, or a natural light which is stronger than that which I have received from Him, since it is proper to the finite understanding not to comprehend a multitude of things, and it is proper to a created understanding to be finite; on the contrary, I have every reason to render thanks to God who owes me nothing and who has given me all the perfections I possess, and I should be far from charging Him with injustice, and with having deprived me of, or wrongfully withheld from me, these perfections which he has not bestowed upon me.

(11) What is wrong with this attack?

One might also criticize God for giving me such a boundless will.

            I have further no reason to complain that he has given me a will more ample than my understanding, for since the will consists only of one single element, and is so to speak indivisible, it appears that its nature is such that nothing can be abstracted from it [without destroying it]; and certainly the more comprehensive it is found to be, the more reason I have to render gratitude to the giver.

(12) What is wrong with this attack?

One might criticize God for allowing us to extend our will beyond our knowledge. In reply, Descartes argues that God merely allows us to make erroneous willful judgments, but does not cause us to make them.

            And, finally, I must also not complain that God collaborates with me in forming the acts of the will, that is the judgment in which I go astray, because these acts are entirely true and good, inasmuch as they depend on God. And in a certain sense more perfection accrues to my nature from the fact that I can form them, than if I could not do so. As to the privation in which alone the formal reason of error or sin consists, it has no need of any approval from God, since it is not a thing [or an existence], and since it is not related to God as to a cause, but should be termed merely a negation [according to the significance given to these words in the Schools]. For in fact it is not an imperfection in God that he has given me the liberty to give or withhold my assent from certain things as to which he has not placed a clear and distinct knowledge in my understanding. But it is without doubt an imperfection in me not to make a good use of my freedom, and to give my judgment readily on matters which I only understand obscurely.

(13) How do the “Schools” (that is, medieval philosophers) understand the privation of our wills?

Perhaps God should Actively Help Me. One might also criticize God for not more actively preventing me from erring. For example, God could have given me clear and distinct perception of everything I would ever need to know. Alternatively, God could have impressed more firmly on my memory the importance of not extending my will beyond my knowledge.

I nevertheless perceive that God could easily have created me so that I never should err, although I still remained free, and endowed with a limited knowledge. He could have done this by giving to my understanding a clear and distinct intelligence of all things as to which I should ever have to deliberate. Or simply, he could have engraved deeply in my memory the resolution never to form a judgment on anything without having a clear and distinct understanding of it, so that I could never forget it. And it is easy for me to understand that, in so far as I consider myself alone, and as if there were only myself in the world, I should have been much more perfect than I am, if God had created me so that I could never err. Nevertheless I cannot deny that in some sense it is a greater perfection in the whole universe that certain parts should not be exempt from error as others are than that all parts should be exactly similar. And I have no right to complain if God, having placed me in the world, has not called upon me to play a part that excels all others in distinction and perfection.

(14) What is wrong with these attacks?

GOOD HABITS OF AVOIDING ERROR. Descartes argues that we don’t need God to impress more firmly on our memories the importance of restraining the will. By developing the right habits, we can do this ourselves.

            And further I have reason to be glad on the ground that if he has not given me the power of never going astray by the first means pointed out above, which depends on a clear and evident knowledge of all the things regarding which I can deliberate, he has at least left within my power the other means, which is firmly to adhere to the resolution never to give judgment on matters whose truth is not clearly known to me; for although I notice a certain weakness in my nature in that I cannot continually concentrate my mind on one single thought, I can yet, by attentive and frequently repeated meditation, impress it so forcibly on my memory that I will never fail to recollect it whenever I have need of it, and thus acquire the habit of never going astray.

(15) How does Descartes recommend that we acquire a habit of not erring?

            And inasmuch as it is in this that the greatest and principal perfection of man consists, it seems to me that I have not gained little by this day’s Meditation, since I have discovered the source of falsity and error. And certainly there can be no other source than that which I have explained; for as often as I so restrain my will within the limits of my knowledge that it forms no judgment except on matters which are clearly and distinctly represented to it by the understanding, I can never be deceived; for every clear and distinct conception is without doubt something, and hence cannot derive its origin from what is nothing, but must of necessity have God as its author -- God, I say, who being supremely perfect, cannot be the cause of any error; and consequently we must conclude that such a conception [or such a judgment] is true. Nor have I only learned to-day what I should avoid in order that I may not err, but also how I should act in order to arrive at a knowledge of the truth; for without doubt I will arrive at this end if I devote my attention sufficiently to those things which I perfectly understand; and if I separate from these that which I only understand confusedly and with obscurity. To these I will henceforth diligently give heed.

SYNOPSIS. Descartes’ synopsis of the Fourth Meditation (initially presented at the opening of his Meditations) is as follows.

            In the fourth Meditation it is shown that all these things which we very clearly and distinctly perceive are true, and at the same time it is explained in what the nature of error or falsity consists. This must of necessity be known both for the confirmation of the preceding truths and for the better comprehension of those that follow. (But it must meanwhile be remarked that I do not in any way there treat of sin -- that is to say of the error which is committed in the pursuit of good and evil, but only of that which arises in the deciding between the true and the false. And I do not intend to speak of matters pertaining to the Faith or the conduct of life, but only of those which concern speculative truths, and which may be known by the sole aid of the light of nature.)

MEDITATION V:

OF THE ESSENCE OF MATERIAL THINGS,

AND, AGAIN, OF GOD, THAT HE EXISTS.

            In the Fifth Meditation, Descartes presents another argument for God’s existence. Like the argument in Meditation III, Descartes’ argument here does not appeal to sensory information (such as natural design). Instead, it is based on the content of his thoughts. The proof in this Meditation follows Anselm’s ontological argument.

ESSENTIAL QUALITIES OF OBJECTS. Descartes begins Meditation Five noting that he can imagine an array of two and three dimensional shapes. Some of these, like triangles, portray such clear and distinct attributes which necessarily belong to them.

Many other matters respecting the attributes of God and my own nature or mind remain for consideration. But I will possibly on another occasion resume the investigation of these. Now (after first noting what must be done or avoided, in order to arrive at a knowledge of the truth) my principal task is to try to emerge from the state of doubt into which I have these last days fallen, and to see whether nothing certain can be known regarding material things.

            But before examining whether any such objects as I conceive exist outside of me, I must consider the ideas of them in so far as they are in my thought, and see which of them are distinct and which confused.

            In the first place, I am able distinctly to imagine that quantity which philosophers commonly call continuous, or the extension in length, breadth, or depth, that is in this quantity, or rather in the object to which it is attributed. Further, I can number in it many different parts, and attribute to each of its parts many sorts of size, figure, situation and local movement, and, finally, I can assign to each of these movements all degrees of duration.

            And not only do I know these things with distinctness when I consider them in general, but, likewise [however little I apply my attention to the matter], I discover an infinitude of particulars respecting numbers, figures, movements, and other such things, whose truth is so evident, and so well accords with my nature, that when I begin to discover them, it seems to me that I learn nothing new, or recollect what I formerly knew -- that is to say, that I for the first time perceive things which were already present to my mind, although I had not as yet applied my mind to them.

            And what I here find to be most important is that I discover in myself an infinitude of ideas of certain things which cannot be considered to be pure negations, although they may possibly have no existence outside of my thought, and which are not framed by me, although it is within my power either to think or not to think them, but which possess natures which are true and immutable. For example, when I imagine a triangle, although there may nowhere in the world be such a figure outside my thought, or ever have been, there is nevertheless in this figure a certain determinate nature, form, or essence, which is immutable and eternal, which I have not invented, and which in no wise depends on my mind. This appears from the fact that diverse properties of that triangle can be demonstrated, namely, that its three angles are equal to two right angles, that the greatest side is subtended by the greatest angle, and the like. Whether I wish it or do not wish it, I now recognize these very clearly as pertaining to it, although I never thought of the matter at all when I imagined a triangle for the first time, and which therefore cannot be said to have been invented by me.

(1) What is one necessary attribute of a triangle?

            Nor does the objection hold good that possibly this idea of a triangle has reached my mind through the medium of my senses, since I have sometimes seen bodies triangular in shape. Because I can form in my mind an infinitude of other figures regarding which we cannot have the least conception of their ever having been objects of sense, and I can nevertheless demonstrate various properties pertaining to their nature as well as to that of the triangle, and these must certainly all be true since I conceive them clearly. Hence they are something, and not pure negation. For it is perfectly clear that all that is true is something, and I have already fully demonstrated that all that I know clearly is true. And even although I had not demonstrated this, the nature of my mind is such that I could not prevent myself from holding them to be true so long as I conceive them clearly. And I recollect that even when I was still strongly attached to the objects of sense, I counted as the most certain those truths which I conceived clearly as regards figures, numbers, and the other matters which pertain to arithmetic and geometry, and, in general, to pure and abstract mathematics.

ONTOLOGICAL ARGUMENT FOR GOD. Since from the mere idea of a triangle one can deduce necessary attributes of a triangle, in the same way, from the mere idea of God (that is, a supremely perfect being) we can arrive at necessary attributes that belong to him.

            But now, if just because I can draw the idea of something from my thought, it follows that all which I know clearly and distinctly as pertaining to this object does really belong to it, may I not derive from this an argument demonstrating the existence of God? It is certain that I no less find the idea of God, that is to say, the idea of a supremely perfect being, in me, than that of any figure or number whatever it is. And I do not know any less clearly and distinctly that an [actual and] eternal existence pertains to this nature than I know that all that which I am able to demonstrate of some figure or number truly pertains to the nature of this figure or number, and therefore, although all that I concluded in the preceding Meditations were found to be false, the existence of God would pass with me as at least as certain as I have ever held the truths of mathematics (which concern only numbers and figures) to be.

(2) What attribute clearly and distinctly pertains to the nature of a supremely perfect being?

Put more precisely, Descartes’ proof of God is this:

(a)        I have an idea of a supremely perfect being

(b)        The idea of this being necessarily entails every perfection

(c)        Existence is a perfection

(d)        Therefore, the idea of a supremely perfect being entails existence (that is, a supremely perfect being exists)

REPLIES TO POSSIBLE CRITICISMS. Descartes next anticipates three possible objections to his argument.

Perhaps We can Separate God’s Existence from his Essence. A first objection to Descartes’ proof is God can be thought of as not existing. That is, we can separate his existence from his essential attributes.

            This indeed is not at first evident, since it would seem to present some appearance of being a sophism. For being accustomed in all other things to make a distinction between existence and essence, I easily persuade myself that the existence can be separated from the essence of God, and that we can thus conceive God as not actually existing. But, nevertheless, when I think of it with more attention, I clearly see that existence can no more be separated from the essence of God than can its having its three angles equal to two right angles be separated from the essence of a [rectilinear] triangle, or the idea of a mountain from the idea of a valley; and so there is not any less repugnance to our conceiving a God (that is, a Being supremely perfect) to whom existence is lacking (that is to say, to whom a certain perfection is lacking), than to conceive of a mountain which has no valley.

(3) Since, according to the critic, we can conceive of God as not existing, then existence is not a necessary attribute of this idea. What is Descartes’ reply?

Perhaps Having a Necessary Quality Doesn’t Imply Existence. A second objection to Descartes’ proof is that even though a necessary attribute of a mountain is that it be adjacent to a valley, it doesn’t follow that any mountains or valleys exist. In the same way, even though the concept of supremely perfect being necessarily possesses certain attributes, it doesn’t follow that this being exists.

            But although I cannot really conceive of a God without existence any more than a mountain without a valley, still from the fact that I conceive of a mountain with a valley, it does not follow that there is such a mountain in the world. Similarly although I conceive of God as possessing existence, it would seem that it does not follow that there is a God which exists. For my thought does not impose any necessity upon things, and just as I may imagine a winged horse, although no horse with wings exists, so I could perhaps attribute existence to God, although no God existed.

            But a sophism is concealed in this objection; for from the fact that I cannot conceive a mountain without a valley, it does not follow that there is any mountain or any valley in existence, but only that the mountain and the valley, whether they exist or do not exist, cannot in any way be separated one from the other. While from the fact that I cannot conceive God without existence, it follows that existence is inseparable from Him, and hence that he really exists; not that my thought can bring this to pass, or impose any necessity on things, but, on the contrary, because the necessity which lies in the thing itself, that is, the necessity of the existence of God determines me to think in this way. For it is not within my power to think of God without existence (that is of a supremely perfect Being devoid of a supreme perfection) though it is in my power to imagine a horse either with wings or without wings.

(4) What is the sophism which Descartes believes is lurking here?

Perhaps we Don’t need to Consider the Idea of God. A third criticism of Descartes’ proof is that if we don’t bother considering the idea of a supremely perfect being, then we won’t be forced into asserting that existence is one of his perfections.

            And we must not here object that it is in truth necessary for me to assert that God exists after having presupposed that he possesses every sort of perfection, since existence is one of these, but that as a matter of fact my original supposition was not necessary, just as it is not necessary to consider that all quadrilateral figures can be inscribed in the circle; for supposing I thought this, I should be constrained to admit that the rhombus might be inscribed in the circle since it is a quadrilateral figure, which, however, is evidently false. [We must not, I say, make any such allegations because] although it is not necessary that I should at any time entertain the notion of God, nevertheless whenever it happens that I think of a first and a sovereign Being, and, so to speak, derive the idea of Him from the storehouse of my mind, it is necessary that I should attribute to Him every sort of perfection, although I do not get so far as to enumerate them all, or to apply my mind to each one in particular.

(5) What is Descartes’ reply to the objection that we don’t need to consider the idea of God?

And this necessity suffices to make me conclude (after having recognized that existence is a perfection) that this first and sovereign being really exists. Just as though it is not necessary for me ever to imagine any triangle, yet, whenever I wish to consider a rectilinear figure composed only of three angles, it is absolutely essential that I should attribute to it all those properties which serve to bring about the conclusion that its three angles are not greater than two right angles, even although I may not then be considering this point in particular. But when I consider which figures are capable of being inscribed in the circle, it is in no wise necessary that I should think that all quadrilateral figures are of this number. On the contrary, I cannot even pretend that this is the case, so long as I do not desire to accept anything which I cannot conceive clearly and distinctly. And in consequence there is a great difference between the false suppositions such as this, and the true ideas born within me, the first and principal of which is that of God.

(6) When we do consider the idea of God, what does it necessarily contain?

Descartes argues that not only does the idea of God necessarily include existence, but the initial idea of God itself is innate.

For really I discern in many ways that this idea is not something factitious, and depending solely on my thought, but that it is the image of a true and immutable nature; first of all, because I cannot conceive anything but God himself to whose essence existence [necessarily] pertains; in the second place because it is not possible for me to conceive two or more Gods in this same position; and, granted that there is one such God who now exists, I see clearly that it is necessary that he should have existed from all eternity, and that he must exist eternally; and finally, because I know an infinitude of other properties in God, none of which I can either diminish or change.

(7) Descartes gives three reasons showing that he is not inventing existence as an attribute of God. What are these reasons?

Unlike elaborate proofs in geometry, Descartes argues that it is quite easy to understand that existence is a necessary attribute of a supremely perfect being.

            For the rest, whatever proof or argument I avail myself of, we must always return to the point that it is only those things which we conceive clearly and distinctly that have the power of persuading me entirely. And although amongst the matters which I conceive of in this way, some indeed are evidently obvious to all, while others only evident themselves to those who consider them closely and examine them attentively. Still, after they have once been discovered, the latter are not considered any less certain than the former. For example, in the case of every right-angled triangle, it does not so evidently appear that the square of the base is equal to the squares of the two other sides as that this base is opposite to the greatest angle. Still, when this has once been understood, we are just as certain of its truth as of the truth of the other. And as regards God, if my mind were not pre-occupied with prejudices, and if my thought did not find itself on all hands diverted by the continual pressure of sensible things, there would be nothing which I could know more immediately and more easily than Him. For is there anything more evident than that there is a God, that is to say, a Supreme Being, to whose essence alone existence pertains?

CONTINUED CONFIDENCE IN PROOFS. Descartes argues that absolute knowledge of anything, including geometry, depends on a prior knowledge of God. Suppose we are analyzing an elaborate geometrical proof. While all of the ideas are fresh in our minds, we can see that the proof is sound. However, as time passes, the details of the proof are no longer in our minds, and we might then doubt the soundness of our proof.

            And although for a firm grasp of this truth I have need of a strenuous application of mind, at present I not only feel myself to be as assured of it as of all that I hold as most certain, but I also remark that the certainty of all other things depends on it so absolutely, that without this knowledge it is impossible ever to know anything perfectly.

            For although I am of such a nature that as long as I understand anything very clearly and distinctly, I am naturally impelled to believe it to be true, yet because I am also of such a nature that I cannot have my mind constantly fixed on the same object in order to perceive it clearly, and as I often recollect having formed a past judgment without at the same time properly recollecting the reasons that led me to make it, it may happen meanwhile that other reasons present themselves to me, which would easily cause me to change my opinion, if I were ignorant of the facts of the existence of God, and thus I should have no true and certain knowledge, but only vague and vacillating opinions. Thus, for example, when I consider the nature of a [rectilinear] triangle, I who have some little knowledge of the principles of geometry recognize quite clearly that the three angles are equal to two right angles, and it is not possible for me not to believe this so long as I apply my mind to its demonstration; but so soon as I abstain from attending to the proof, although I still recollect having clearly comprehended it, it may easily occur that I come to doubt its truth, if I am ignorant of there being a God. For I can persuade myself of having been so constituted by nature that I can easily deceive myself even in those matters which I believe myself to grasp with the greatest evidence and certainty, especially when I recollect that I have frequently judged matters to be true and certain which other reasons have afterwards impelled me to judge to be altogether false.

            But after I have recognized that there is a God -- because at the same time I have also recognized that all things depend upon Him, and that he is not a deceiver, and from that have inferred that what I perceive clearly and distinctly cannot fail to be true -- although I no longer pay attention to the reasons for which I have judged this to be true, provided that I recollect having clearly and distinctly perceived it no contrary reason can be brought forward which could ever cause me to doubt of its truth. And thus I have a true and certain knowledge of it. And this same knowledge extends likewise to all other things which I recollect having formerly demonstrated, such as the truths of geometry and the like; for what can be alleged against them to cause me to place them in doubt? Will it be said that my nature is such as to cause me to be frequently deceived? But I already know that I cannot be deceived in the judgment whose grounds I know clearly. Will it be said that I formerly held many things to be true and certain which I have afterwards recognized to be false? But I had not had any clear and distinct knowledge of these things, and not as yet knowing the rule whereby I assure myself of the truth, I had been impelled to give my assent from reasons which I have since recognized to be less strong than I had at the time imagined them to be. What further objection can then be raised? That possibly I am dreaming (an objection I myself made a little while ago), or that all the thoughts which I now have are no more true than the fantasies of my dreams? But even though I slept the case would be the same, for all that is clearly present to my mind is absolutely true.

(8) How does God’s existence assure us that we can trust that a geometrical proof is sound, even when the details of the proof are no longer before our minds?

            And so I very clearly recognize that the certainty and truth of all knowledge depends alone on the knowledge of the true God, in so much that, before I knew Him, I could not have a perfect knowledge of any other thing. And now that I know Him I have the means of acquiring a perfect knowledge of an infinitude of things, not only of those which relate to God Himself and other intellectual matters, but also of those which pertain to corporeal nature in so far as it is the object of pure mathematics [which have no concern with whether it exists or not].

SYNOPSIS. Descartes’ synopsis of the Fifth Meditation (initially presented at the opening of his Meditations) is as follows.

            In the fifth Meditation corporeal nature generally is explained, and in addition to this the existence of God is demonstrated by a new proof in which there may possibly be certain difficulties also, but the solution of these will be seen in the Replies to the Objections. And further I show in what sense it is true to say that the certainty of geometrical demonstrations is itself dependent on the knowledge of God.

F. MEDITATION VI:

OF THE EXISTENCE OF MATERIAL THINGS,

AND OF THE REAL DISTINCTION BETWEEN THE SOUL AND BODY OF MAN

            At this point in the Meditations, Descartes has obtained certainty about a variety of topics: his existence, his essence, the causal principle, God’s existence, that God made him, that God is not a deceiver, that clarity and distinctness are indicators of truth, that he has a free will, the source of error, and that God is the source of confidence in elaborate proofs. Descartes sets two aims in Meditation VI: first, to show the existence of material objects, and, second, to show that mind is distinct from body.

EXISTENCE OF PRIMARY OBJECTS. Recalling the distinction made earlier between primary objects of perception (objects of mathematics) and secondary objects of perception (objects of the senses), Descartes investigates whether material objects exist by asking two questions: (1) do primary objects exist? and (2) do secondary objects exist? In answering the first question, Descartes draws on a distinction between imagining primary objects and conceiving of primary objects. He notes that he conceives of primary objects (such as triangles) clearly and distinctly, but this in no way means that such objects actually exist. It only means that they might exist since the idea contains no contradiction. In addition to conceiving of primary objects, though, Descartes says that he can imagine many primary objects as well.

Nothing further now remains but to inquire whether material things exist. And certainly I at least know that these may exist in so far as they are considered as the objects of pure mathematics, since in this aspect I perceive them clearly and distinctly. For there is no doubt that God possesses the power to produce everything that I am capable of perceiving with distinctness, and I have never deemed that anything was impossible for Him, unless I found a contradiction in attempting to conceive it clearly. Further, the faculty of imagination which I possess, and of which, experience tells me, I make use when I apply myself to the consideration of material things, is capable of persuading me of their existence. For when I attentively consider what imagination is, I find that it is nothing but a certain application of the faculty of knowledge to the body which is immediately present to it, and which therefore exists.

Imagination and Conception. Descartes continues by illustrating the difference between conception and imagination.

            And to render this quite clear, I remark in the first place the difference that exists between the imagination and pure intellection [or conception]. For example, when I imagine a triangle, I do not conceive it only as a figure comprehended by three lines, but I also see these three lines as present by the power and inward vision of my mind, and this is what I call imagining. But if I desire to think of a chiliagon, I certainly conceive truly that it is a figure composed of a thousand sides, just as easily as I conceive of a triangle that it is a figure of three sides only; but I cannot in any way imagine the thousand sides of a chiliagon [as I do the three sides of a triangle], nor do I, so to speak, regard them as present [with the eyes of my mind]. And although in accordance with the habit I have formed of always employing the aid of my imagination when I think of corporeal things, it may happen that in imagining a chiliagon I confusedly represent to myself some figure, yet it is very evident that this figure is not a chiliagon, since it in no way differs from that which I represent to myself when I think of a myriagon or any other many-sided figure. Nor does it serve my purpose in discovering the properties which go to form the distinction between a chiliagon and other polygons. But if the question turns upon a pentagon, it is quite true that I can conceive its figure as well as that of a chiliagon without the help of my imagination. But I can also imagine it by applying the attention of my mind to each of its five sides, and at the same time to the space which they enclose. And thus I clearly recognize that I have need of a particular effort of mind in order to effect the act of imagination, such as I do not require in order to understand. And this particular effort of mind clearly shows the difference which exists between imagination and pure intellection.

(1) How does Descartes’ chiliagon example illustrate the difference between conception and imagination?

Descartes notes another distinction between conception and imagination: one faculty is necessary to who he is, and the other is not.

            I remark besides that this power of imagination which is in one, inasmuch as it differs from the power of understanding, is in no wise a necessary element in my nature, or in [my essence, that is to say, in] the essence of my mind. For although I did not possess it I should doubtless ever remain the same as I now am, from which it appears that we might conclude that it depends on something which differs from me. And I easily conceive that if some body exists with which my mind is conjoined and united in such a way that it can apply itself to consider it when it pleases, it may be that by this means it can imagine corporeal objects; so that this mode of thinking differs from pure intellection only inasmuch as mind in its intellectual activity in some manner turns on itself, and considers some of the ideas which it possesses in itself; while in imagining it turns towards the body, and there beholds in it something conformable to the idea which it has either conceived of itself or perceived by the senses. I easily understand, I say, that the imagination could be thus constituted if it is true that body exists; and because I can discover no other convenient mode of explaining it, I conjecture with probability that body does exist. But this is only with probability, and although I examine all things with care, I nevertheless do not find that from this distinct idea of corporeal nature, which I have in my imagination, I can derive any argument from which there will necessarily be deduced the existence of body.

(2) Between conception and imagination, which of the two is not a necessary attribute of humans, and why?

(3) What does Descartes conclude to be the difference between conception (pure intellection) and imagination?

Since Descartes can conceive of primary objects, then such objects possibly exist. Since he can also imagine these objects, then such objects probably exist, yet he cannot say for sure whether they do exist.

PERCEPTION AND THE EXISTENCE OF SECONDARY OBJECTS. Failing to attain certainty about the existence of primary material objects, Descartes turns his attention to secondary material objects. Since his notion of secondary objects rests on his faculty of secondary perception (which still might only be an illusion) he needs to explore this faculty. He does this by giving a summary of the first three Meditations, noting what conclusions he has already arrived at about secondary perception.

            But I am in the habit of imagining many other things besides this corporeal nature which is the object of pure mathematics, namely, the colors, sounds, scents, pain, and other such things, although less distinctly. And inasmuch as I perceive these things much better through the senses, by the medium of which, and by the memory, they seem to have reached my imagination, I believe that, in order to examine them more conveniently, it is right that I should at the same time investigate the nature of sense perception, and that I should see if from the ideas which I grasp by this mode of thought, which I call feeling, I cannot derive some certain proof of the existence of corporeal objects.

            And first of all I will recall to my memory those matters which I until now held to be true, as having perceived them through the senses, and the foundations on which my belief has rested; in the next place I will examine the reasons which have since obliged me to place them in doubt; in the last place I will consider which of them I must now believe.

Naive Confidence in Senses. He recalls first that he had a naive confidence in his senses (secondary perception) by which he perceived the different parts of his body, different emotional and physiological appetites, and various secondary qualities in objects such as heat and color.

            First of all, then, I perceived that I had a head, hands, feet, and all other members of which this body -- which I considered as a part, or possibly even as the whole, of myself -- is composed. Further I was sensible that this body was placed amidst many others, from which it was capable of being affected in many different ways, beneficial and hurtful, and I remarked that a certain feeling of pleasure accompanied those that were beneficial, and pain those which were harmful. And in addition to this pleasure and pain, I also experienced hunger, thirst, and other similar appetites, as also certain corporeal inclinations towards joy, sadness, anger, and other similar passions. And outside myself, in addition to extension, figure, and motions of bodies, I remarked in them hardness, heat, and all other tactile qualities, and, further, light and color, and scents and sounds. The variety of these gave me the means of distinguishing the sky, the earth, the sea, and generally all the other bodies, one from the other. And certainly (considering the ideas of all these qualities which presented themselves to my mind, and which alone I perceived properly or immediately) it was not without reason that I believed myself to perceive objects quite different from my thought, namely, bodies from which those ideas proceeded. For I found by experience that these ideas presented themselves to me without my consent being requisite, so that I could not perceive any object, however desirous I might be, unless it were present to the organs of sense; and it was not in my power not to perceive it, when it was present. And because the ideas which I received through the senses were much more lively, more clear, and even, in their own way, more distinct than any of those which I could of myself frame in meditation, or than those I found impressed on my memory, it appeared as though they could not have proceeded from my mind, so that they must necessarily have been produced in me by some other things. And having no knowledge of those objects except the knowledge which the ideas themselves gave me, nothing was more likely to occur to my mind than that the objects were similar to the ideas which were caused. And because I likewise remembered that I had formerly made use of my senses rather than my reason, and recognized that the ideas which I formed of myself were not so distinct as those which I perceived through the senses, and that they were most frequently even composed of portions of these last, I persuaded myself easily that I had no idea in my mind which had not formerly come to me through the senses. Nor was it without some reason that I believed that this body (which be a certain special right I call my own) belonged to me more properly and more strictly than any other. For in fact I could never be separated from it as from other bodies. I experienced in it and on account of it all my appetites and affections, and finally I was touched by the feeling of pain and the titillation of pleasure in its parts, and not in the parts of other bodies which were separated from it. But when I inquired as to why sadness of mind follows from some (I know not what) painful sensation, and joy arises from the pleasurable sensation, or why this mysterious pinching of the stomach which I call hunger causes me to desire to eat, and dryness of throat causes a desire to drink, and so on, I could give no reason except that nature taught me so. For there is certainly no affinity (that I at least can understand) between the craving of the stomach and the desire to eat, any more than between the perception of whatever causes pain and the thought of sadness which arises from this perception. And in the same way it appeared to me that I had learned from nature all the other judgments which I formed regarding the objects of my senses, since I remarked that these judgments were formed in me before I had the leisure to weigh and consider any reasons which might oblige me to make them.

(4) Descartes notes that painful sensations cause sadness, and pleasurable sensations cause joy. What taught him to connect such emotions to such sensations?

(5) What taught him to make judgments regarding objects of he senses?

Loss of Confidence in Senses. Descartes next recalls how he gradually lost all confidence in the reliability of these secondary perceptions. There were three steps to this doubting process. First, we are misguided by optical illusions. Second, our perceptions may be dream states, and, third, God might be deceiving us.

            But afterwards many experiences little by little destroyed all the faith which I had rested in my senses. For I from time to time observed that those towers which from afar appeared to me to be round, more closely observed seemed square, and that colossal statues raised on the summit of these towers, appeared as quite tiny statues when viewed from the bottom; and so in an infinitude of other cases I found error in judgments founded on the external senses. And not only did I lose faith in those founded on the external senses, but even in those founded on the internal as well. For is there anything more intimate or more internal than pain? And yet I have learned from some persons whose arms or legs have been cut off, that they sometimes seemed to feel pain in the part which had been amputated, which made me think that I could not be quite certain that it was a certain member which pained me, even although I felt pain in it. And to those grounds of doubt I have lately added two others, which are very general. The first is that I never have believed myself to feel anything in waking moments which I cannot also sometimes believe myself to feel when I sleep, and as I do not think that these things which I seem to feel in sleep, proceed from objects outside of me, I do not see any reason why I should have this belief regarding objects which I seem to perceive while awake. The other was that being still ignorant, or rather supposing myself to be ignorant, of the author of my being, I saw nothing to prevent me from having been so constituted by nature that I might be deceived even in matters which seemed to me to be most certain. And as to the grounds on which I was formerly persuaded of the truth of sensible objects, I had not much trouble in replying to them. For since nature seemed to cause me to lean towards many things from which reason repelled me, I did not believe that I should trust much to the teachings of nature. And although the ideas which I receive by the senses do not depend on my will, I did not think that one should for that reason conclude that they proceeded from things different from myself, since possibly some faculty might be discovered in me -- though until now unknown to me -- which produced them.

(6) Descartes says that external sensations seem to arise from a source outside of himself, since such sensations don’t depend on his will. What is another possible source of these external sensations?

Identity as a Thinking Thing. Descartes recalls how he attained certainty that God would not deceive him about his clear and distinct ideas. One such idea concerns the identity as a thinking thing. Even though he may have a body, his true identity is that of a thinking thing alone.

            But now that I begin to know myself better, and to discover more clearly the author of my being, I do not in truth think that I should rashly admit all the matters which the senses seem to teach us, but, on the other hand, I do not think that I should doubt them all universally.

            And first of all, because I know that all things which I perceive clearly and distinctly can be created by God as I understand them, it suffices that I am able to perceive one thing apart from another clearly and distinctly in order to be certain that the one is different from the other, since they may be made to exist in separation at least by the omnipotence of God. And it does not signify by what power this separation is made in order to compel me to judge them to be different. And, therefore, just because I know certainly that I exist, and that meanwhile I do not remark that any other thing necessarily pertains to my nature or essence, except that I am a thinking thing, I rightly conclude that my essence consists solely in the fact that I am a thinking thing [or a substance whose whole essence or nature is to think]. And although possibly (or rather certainly, as I will say in a moment) I possess a body with which I am very intimately conjoined, it is certain that this I [that is to say, my soul by which I am what I am], is entirely and absolutely distinct from my body, and can exist without it. This is because, on the one hand, I have a clear and distinct idea of myself inasmuch as I am only a thinking and unextended thing, and as, on the other, I possess a distinct idea of body, inasmuch as it is only an extended and unthinking thing,

(7) What are the two reasons Descartes gives for concluding that his mind could exist without his body?

He argues that humans are spirits which occupy a mechanical body, and that the essential attributes of humans are exclusively attributes of the spirit (such as thinking, willing and conceiving) which do not involve the body at all. Attributes, such as sense perception, movement, and appetite require a body, are attributes of our body and not of our spirit and, hence, do not comprise our essence.

Faculties of Thinking. Descartes explains that we are designed with several mental faculties which are responsible for various ways of thinking. Descartes is most concerned here with the passive faculty of perception.

            I further find in myself faculties employing modes of thinking peculiar to themselves, namely, the faculties of imagination and feeling, without which I can easily conceive myself clearly and distinctly as a complete being; while, on the other hand, they cannot be so conceived apart from me, that is without an intelligent substance in which they reside, for [in the notion we have of these faculties, or, to use the language of the Schools] in their formal concept, some kind of intellection is comprised, from which I infer that they are distinct from me as its modes are from a thing. I observe also in me some other faculties such as that of change of position, the assumption of different figures and such like, which cannot be conceived, any more than can the preceding, apart from some substance to which they are attached, and consequently cannot exist without it; but it is very clear that these faculties, if it be true that they exist, must be attached to some corporeal or extended substance, and not to an intelligent substance, since in the clear and distinct conception of these there is some sort of extension found to be present, but no intellection at all. There is certainly further in me a certain passive faculty of perception, that is, of receiving and recognizing the ideas of sensible things. But this would be useless to me [and I could in no way benefit from it], if there were not either in me or in some other thing another active faculty capable of forming and producing these ideas.

(8) What is the passive faculty of perception?

Existence of External Objects. Connected to the passive faculty of perception is an active source of the perceptions which we receive. That is, if I passively (or non-willfully) perceive a rock in front of me, then there is some active source feeding me that perception. Descartes sees only three possible explanations of that active source: the perceptions are actively produced by either himself, God, or external objects. He eliminates the first two options and concludes that external objects are the active source of such perceptions.

But this active faculty cannot exist in me [inasmuch as I am a thing that thinks] seeing that it does not presuppose thought, and also that those ideas are often produced in me without my contributing in any way to the same, and often even against my will. It is thus necessarily the case that the faculty resides in some substance different from me in which all the reality which is objectively in the ideas that are produced by this faculty is formally or eminently contained, as I remarked before. And this substance is either a body, that is, a corporeal nature in which there is contained formally [and really] all that which is objectively [and by representation] in those ideas, or it is God Himself, or some other creature more noble than body in which that same is contained eminently. But, since God is no deceiver, it is very evident that he does not communicate to me these ideas immediately and by Himself, nor yet by the intervention of some creature in which their reality is not formally, but only eminently, contained. For since he has given me no faculty to recognize that this is the case, but, on the other hand, a very great inclination to believe [that they are sent to me or] that they are conveyed to me by corporeal objects, I do not see how he could be defended from the accusation of deceit if these ideas were produced by causes other than corporeal objects. Hence we must allow that corporeal things exist. However, they are perhaps not exactly what we perceive by the senses, since this comprehension by the senses is in many instances very obscure and confused. But we must at least admit that all things which I conceive in them clearly and distinctly, that is to say, all things which, speaking generally, are comprehended in the object of pure mathematics, are truly to be recognized as external objects.

(9) Why does Descartes rule out himself as the active source of perceptions?

(10) Why does Descartes rule out God as the active source of perception?

Stated briefly, Descartes’ argument for the existence external objects is as follows:

(a) I know clearly and distinctly that there is in me a passive faculty which receives perceptions from an active source

(b) This active source of perception is either me, God, or external objects

(c) I am not that active source since such perceptions are not willfully produced and does not involve thinking (my true essence)

(d) God does not implants ideas of perception in me since this would be deception

(e) Therefore, external objects are the active source of perceptions

For Descartes, (d) above is the crucial premise to his argument. Why does he believe that perceptions are not implanted in him by God? The answer is that, first, Descartes has no faculty by which he could know if such perceptions are implanted by God. Second, he has a strong inclination to believe that secondary perceptions are the result of secondary external objects. Third, Descartes argues that it would be deception on God’s part if God (a) permitted Descartes to erroneously believe perceptions are caused by objects and (b) did not give him a faculty to know that such notions are actually caused by God. Descartes has here expanded on the notion of God not being a deceiver. In Meditation Three, God’s quality of non-deception was commissive in that a perfect God could not commit any act which would deceive. Here, however, Descartes argues that a perfect God cannot omit any preventative measures which would help Descartes understand the truth. God’s non-deception, then, is also omissive. This commissive/omissive distinction is similar to the notion of sins of commission (such as the direct stabbing of an innocent person) and sins of omission (such as refusing to rescue a person from drowning). Descartes maintains, then, that a non-deceptive God can perform neither deceptions of commission, nor deceptions of omission.

THINGS NATURE TEACHES US. Even though Descartes is confident that such perceptions result from external objects, he still has reservations about the reliability of this sense perception. Descartes addresses the issue by looking at the somewhat ambiguous manner in which nature teaches him about external objects. In the broadest sense, natural teachings are any dispositions implanted in us by God. All of these teachings contain some degree of truth.

            Consider other things, however, which are either particular only, as, for example, that the sun is of such and such a figure, etc., or which are less clearly and distinctly conceived, such as light, sound, pain and the like. It is certain that although they are very dubious and uncertain, I may assuredly hope to conclude that I have within me the means of arriving at the truth even here. I conclude this on the sole ground that God is not a deceiver, and that consequently he has not permitted any falsity to exist in my opinion which he has not likewise given me the faculty of correcting. And first of all there is no doubt that in all things which nature teaches me there is some truth contained. For by nature, considered in general, I now understand no other thing than either God Himself or else the order and disposition which God has established in created things. And by my nature in particular I understand no other thing than the complexus of all the things which God has given me.

(11) What does Descartes mean by the term “nature” in general and “nature” in particular?

Natural Teachings which are True. Descartes explains that some things nature teaches us are true and important.

            But there is nothing which this nature teaches me more expressly [nor more sensibly] than that I have a body which is adversely affected when I feel pain, which has need of food or drink when I experience the feelings of hunger and thirst, and so on; nor can I doubt there being some truth in all this.

            Nature also teaches me by these sensations of pain, hunger, thirst, etc., that I am not only lodged in my body as a pilot in a vessel, but that I am not only lodged in my body as a pilot in a vessel, but that I am very closely united to it, and so to speak so intermingled with it that I seem to compose with it one whole. For if that were not the case, when my body is hurt, I, who am merely a thinking thing, should not feel pain, for I should perceive this wound by the understanding only, just as the sailor perceives by sight when something is damaged in his vessel; and when my body has need of drink or food, I should clearly understand the fact without being warned of it by confused feelings of hunger and thirst. For all these sensations of hunger, thirst, pain, etc. are in truth none other than certain confused modes of thought which are produced by the union and apparent intermingling of mind and body.

            Moreover, nature teaches me that many other bodies exist around mine, of which some are to be avoided, and others sought after. And certainly from the fact that I am sensible of different sorts of colors, sounds, scents, tastes, heat, hardness, etc., I very easily conclude that there are in the bodies from which all these diverse sense-perceptions proceed certain variations which answer to them, although possibly these are not really at all similar to them. And also from the fact that amongst these different sense-perceptions some are very agreeable to me and others disagreeable, it is quite certain that my body (or rather myself in my entirety, inasmuch as I am formed of body and soul) may receive different impressions agreeable and disagreeable from the other bodies which surround it.

(12) What are the three important truths which nature teaches us (in each of the three paragraphs above, respectively)?

These truths of nature all hinge on the fact that we are composed of both a mind and body.

Apparent Natural Teachings which are False. Descartes continues that although some things nature teaches are true, other natural teachings may be false.

            But there are many other things which nature seems to have taught me, but which at the same time I have never really received from her, but which have been brought about in my mind by a certain habit which I have of forming inconsiderate judgments on things; and thus it may easily happen that these judgments contain some error. Take, for example, the opinion which I hold that all space in which there is nothing that affects [or makes an impression on] my senses is void; that in a body which is warm there is something entirely similar to the idea of heat which is in me; that in a white or green body there is the same whiteness or greenness that I perceive; that in a bitter or sweet body there is the same taste, and so on in other instances; that the stars, the towers, and all other distant bodies are of the same figure and size as they appear from far off to our eyes, etc.

(13) What are four things which nature seems to teach us that are probably false?

Different Senses of “Nature”. Descartes now has a problem: some things nature teaches us are true, yet some things nature teaches us may be false. His solution is to distinguish between the various ways that nature can teach us something. As noted, all natural teachings are dispositions given to us by God. One subset of natural teachings pertain only to the mind, and these are clear and distinct. The subject matter of such teachings involves purely mental concepts, such as “what is done cannot be undone.” When nature teaches us in this manner, there is no question about the truth of the matter. A second subset of natural teachings pertain only to the body. Descartes does not deal with these. Yet a third subset pertains to the relation between our minds and bodies. These truths are a little more obscure and can be misinterpreted. All of the natural teachings noted above are of this mind/body type. The false ones, then, are simply misinterpretations.

But in order that in this there should be nothing which I do not conceive distinctly, I should define exactly what I really understand when I say that I am taught somewhat by nature. For here I take “nature” in a more limited meaning than when I term it the sum of all the things given me by God. For, in this sum many things are contained which only pertain to mind (and to these I do not refer in speaking of nature) such as the notion which I have of the fact that what has once been done cannot ever be undone and an infinitude of such things which I know by the light of nature [without the help of the body]. And we see that it contains many other matters besides which only pertain to body, and are no longer here contained under the name of “nature,” such as the quality of weight which it possesses and the like, with which I also do not deal. For in talking of nature I only treat of those things given by God to me as a being composed of mind and body. But the nature here described truly teaches me to flee from things which cause the sensation of pain, and seek after the things which communicate to me the sentiment of pleasure and so forth. But I do not see that beyond this it teaches me that from those diverse sense-perceptions we should ever form any conclusion regarding things outside of us, without having [carefully and maturely] mentally examined them beforehand. For it seems to me that it is mind alone, and not mind and body in conjunction, that is requisite to a knowledge of the truth in regard to such things.

(14) What example does Descartes give of a mind/body natural teaching which is accurate?

Descartes examines more carefully the above apparent natural teachings which are false, and explains what is really going on.

Thus, although a star makes no larger an impression on my eye than the flame of a little candle there is yet in me no real or positive propensity impelling me to believe that it is not greater than that flame. But I have judged it to be so from my earliest years, without any rational foundation. And although in approaching fire I feel heat, and in approaching it a little too near I even feel pain, there is at the same time no reason in this which could persuade me that there is in the fire something resembling this heat any more than there is in it something resembling the pain. All that I have any reason to believe from this is that there is something in it, whatever it may be, which excites in me these sensations of heat or of pain. So also, although there are spaces in which I find nothing which excites my senses, I must not from that conclude that these spaces contain no body. For I see in this, as in other similar things, that I have been in the habit of perverting the order of nature. This is because these perceptions of sense have been placed within me by nature merely for the purpose of signifying to my mind what things are beneficial or hurtful to the composite whole of which it forms a part. Being up to that point sufficiently clear and distinct, I yet avail myself of them as though they were absolute rules by which I might immediately determine the essence of the bodies which are outside me, as to which, in fact, they can teach me nothing but what is most obscure and confused.

(15) Consider the example of feeling heat and pain when getting too close to a fire. What part of this experience involves a clear and distinct natural teaching, and what part is an unwarranted perversion?

Confusing Nature’s Signals. Descartes recalls the cause of error as discussed in Meditation Four, that is, extending our will beyond our knowledge. He argues now that another source of error is when we have conflicting signals about what we should pursue or avoid.

            But I have already sufficiently considered how, notwithstanding the supreme goodness of God, falsity enters into the judgments I make. Only here a new difficulty is presented -- one respecting those things the pursuit or avoidance of which is taught me by nature, and also respecting the internal sensations which I possess, and in which I seem to have sometimes detected error [and thus to be directly deceived by my own nature]. To take an example, the agreeable taste of some food in which poison has been intermingled may induce me to partake of the poison, and thus deceive me. It is true, at the same time, that in this case nature may be excused, for it only induces me to desire food in which I find a pleasant taste, and not to desire the poison which is unknown to it. And thus I can infer nothing from this fact, except that my nature is not omniscient, at which there is certainly no reason to be astonished, since man, being finite in nature, can only have knowledge the perfectness of which is limited.

(16) Consider the situation where you desire to eat food which has been poisoned. Why may nature be excused for inclining you to eat something which is poisoned?

Comparing Bad Clocks with Sick Bodies. Descartes anticipates a criticism which compares a sick person who improperly perceives things to a poorly designed clock which gives the wrong time. God, thus, would be at fault for poorly designing humans.

            But we not infrequently deceive ourselves even in those things to which we are directly impelled by nature, as happens with those who when they are sick desire to drink or eat things hurtful to them. It will perhaps be said here that the cause of their deceptiveness is that their nature is corrupt. But that does not remove the difficulty, because a sick man is none the less truly God’s creature as he who is in health. And it is therefore as repugnant to God’s goodness for the one to have a deceitful nature as it is for the other. And as a clock composed of wheels and counter-weights no less exactly observes the laws of nature when it is badly made, and does not show the time properly, than when it entirely satisfies the wishes of its maker. I consider the body of a man as being a sort of machine so built up and composed of nerves, muscles, veins, blood and skin, that though there were no mind in it at all, it would not cease to have the same motions as at present. Exception are made for those movements which are due to the direction of the will, and in consequence depend upon the mind [as opposed to those which operate by the disposition of its organs]. I easily recognize that it would be as natural to this body, supposing it to be, for example, dropsical, to suffer the parchedness of the throat which usually signifies to the mind the feeling of thirst. It would be disposed by this parched feeling to move the nerves and other parts in the way requisite for drinking, and thus to augment its malady and do harm to itself, as it is natural to it, when it has no indisposition, to be impelled to drink for its good by a similar cause. And although, considering the use to which the clock has been destined by its maker, I may say that it deflects from the order of its nature when it does not indicate the hours correctly. And as, in the same way, considering the machine of the human body as having been formed by God in order to have in itself all the movements usually manifested there, I have reason for thinking that it does not follow the order of nature when, if the throat is dry, drinking does harm to the conservation of health.

(17) Under what circumstances does a clock stray from the order (or design) of its nature?

Descartes dismisses this line of reasoning, since it imposes an artificial order on the body by forcing a comparison with clocks.

Nevertheless I recognize at the same time that this last mode of explaining nature is very different from the other. For this is but a purely verbal characterization depending entirely on my thought, which compares a sick man and a badly constructed clock with the idea which I have of a healthy man and a well made clock, and it is hence extrinsic to the things to which it is applied. But according to the other interpretation of the term “nature” I understand something which is truly found in things and which is therefore not without some truth.

            But certainly although in regard to the dropsical body it is only so to speak to apply an extrinsic term when we say that its nature is corrupted, inasmuch as apart from the need to drink, the throat is parched. Yet in regard to the composite whole, that is to say, to the mind or soul united to this body, it is not a purely verbal predicate, but a real error of nature, for it to have thirst when drinking would be hurtful to it. And thus it still remains to inquire how the goodness of God does not prevent the nature of man so regarded from being fallacious.

FOUR SOURCES OF ERROR. Descartes argues that there are four sources of error which are inherently tied to the structure of our physical bodies.

Distinct Attributes of Mind and Body. The first of these stems from the fact that the mind and body are distinct.

            In order to begin this examination, then, I here say, in the first place, that there is a great difference between mind and body, inasmuch as body is by nature always divisible, and the mind is entirely indivisible. For, as a matter of fact, when I consider the mind, that is to say, myself inasmuch as I am only a thinking thing, I cannot distinguish in myself any parts, but understand myself to be clearly one and entire. And although the whole mind seems to be united to the whole body, yet if a foot, or an arm, or some other part, is separated from my body, I am aware that nothing has been taken away from my mind. And the faculties of willing, feeling, conceiving, etc. cannot be properly speaking said to be its parts, for it is one and the same mind which employs itself in willing and in feeling and understanding. But it is quite otherwise with corporeal or extended objects, for there is not one of these imaginable by me which my mind cannot easily divide into parts, and which consequently I do not recognize as being divisible; this would be sufficient to teach me that the mind or soul of man is entirely different from the body, if I had not already learned it from other sources.

(18) What key difference between mind and body results in error?

How the Mind receives Impressions. A second source of error results from the fact that the mind does not receive impressions directly from all parts of the body.

            I further notice that the mind does not receive the impressions from all parts of the body immediately, but only from the brain, or perhaps even from one of its smallest parts, namely, from that in which the common sense is said to reside, which, whenever it is disposed in the same particular way, conveys the same thing to the mind, although meanwhile the other portions of the body may be differently disposed, as is testified by innumerable experiments which it is unnecessary here to recount.

(19) How does the mind receive impressions?

Long Nerves to the Brain. A third source of error arises from the fact that there are long nerves going to and from the brain. If we poke one of these at any place, we will have the same sensation.

            I notice, also, that the nature of body is such that none of its parts can be moved by another part a little way off which cannot also be moved in the same way by each one of the parts which are between the two, although this more remote part does not act at all. As, for example, in the cord ABCD [which is in tension] if we pull the last part D, the first part A will not be moved in any way differently from what would be the case if one of the intervening parts B or C were pulled, and the last part D were to remain unmoved. And in the same way, when I feel pain in my foot, my knowledge of physics teaches me that this sensation is communicated by means of nerves dispersed through the foot, which, being extended like cords from there to the brain, when they are contracted in the foot, at the same time contract the inmost portions of the brain which is their extremity and place of origin, and then excite a certain movement which nature has established in order to cause the mind to be affected by a sensation of pain represented as existing in the foot. But because these nerves must pass through the tibia, the thigh, the loins, the back and the neck, in order to reach from the leg to the brain, it may happen that although their extremities which are in the foot are not affected, but only certain ones of their intervening parts [which pass by the loins or the neck], this action will excite the same movement in the brain that might have been excited there by a hurt received in the foot, in consequence of which the mind will necessarily feel in the foot the same pain as if it had received a hurt. And the same holds good of all the other perceptions of our senses.

(20) Give one of Descartes’ examples of this long nerve phenomenon.

            Feelings which Advance our Preservation. Finally, some bodily feelings are deceptive insofar as they give us exaggerated or misdirected sensations. These, though, are present for the benefit of self-preservation.

            I notice finally that since each of the movements which are in the portion of the brain by which the mind is immediately affected brings about one particular sensation only, we cannot under the circumstances imagine anything more likely than that this movement, amongst all the sensations which it is capable of impressing on it, causes the mind to be affected by that one which is best fitted and most generally useful for the conservation of the human body when it is in health. But experience makes us aware that all the feelings with which nature inspires us are such as I have just spoken of; and there is therefore nothing in them which does not give testimony to the power and goodness of the God [who has produced them]. Thus, for example, when the nerves which are in the feet are violently or more than usually moved, their movement, passing through the medulla of the spine to the inmost parts of the brain, gives a sign to the mind which makes it feel somewhat, namely, pain, as though in the foot, by which the mind is excited to do its utmost to remove the cause of the evil as dangerous and hurtful to the foot. It is true that God could have constituted the nature of man in such a way that this same movement in the brain would have conveyed something quite different to the mind. For example, it might have produced consciousness of itself either in so far as it is in the brain, or as it is in the foot, or as it is in some other place between the foot and the brain, or it might finally have produced consciousness of anything else whatsoever. But none of all this would have contributed so well to the conservation of the body. Similarly, when we desire to drink, a certain dryness of the throat is produced which moves its nerves, and by their means the internal portions of the brain. And this movement causes in the mind the sensation of thirst, because in this case there is nothing more useful to us than to become aware that we have need to drink for the conservation of our health. And the same holds good in other instances.

(21) Give one of Descartes’ examples of an exaggerated bodily feeling which is for the benefit of self-preservation.

RESTORING CONFIDENCE IN BODILY PERCEPTIONS. From these four reasons, Descartes concludes that the construction of our bodies subject us to error.  However, he believes that we can counteract this problem and ultimately have confidence in our bodily perceptions.

Error and the Body.  First, Descartes notes that bodily errors are not haphazard, but have a kind of mechanical logic.

            In spite of the supreme goodness of God, it is quite clear from this that the nature of man cannot be otherwise than sometimes a source of deception, inasmuch as it is composed of mind and body. For if there is any cause which excites, not in the foot but in some part of the nerves which are extended between the foot and the brain, or even in the brain itself, the same movement which usually is produced when the foot is detrimentally affected, pain will be experienced as though it were in the foot, and the sense will thus naturally be deceived. For since the same movement in the brain is capable of causing but one sensation in the mind, and this sensation is much more frequently excited by a cause which hurts the foot than by another existing in some other quarter, it is reasonable that it should convey to the mind pain in the foot rather than in any other part of the body. And the parchedness of the throat does not always proceed, as it usually does, from the fact that drinking is necessary for the health of the body, but sometimes comes from quite a different cause (as is the case with dropsical patients). However, it is much better that it should mislead on this occasion than if, on the other hand, it were always to deceive us when the body is in good health. And so on in similar cases.

(22) Descartes concedes that our bodies often mislead us when we are sick. However, he finds this better than an alternative possibility. What is that possibility?

Countering Misleading Perceptions. Descartes notes ways that we can counter the misleading effects of bodily perceptions and can ultimately rely on his senses.

            And certainly this consideration is of great service to me, not only in enabling me to recognize all the errors to which my nature is subject, but also in enabling me to avoid them or to correct them more easily. For, I know that all my senses more frequently indicate to me truth than falsehood respecting the things which concern that which is beneficial to the body. And, I am able almost always to avail myself of many of them in order to examine one particular thing. And, besides that, I am able to make use of my memory in order to connect the present with the past, and of my understanding which already has discovered all the causes of my errors. Thus, I ought no longer to fear that falsity may be found in matters every day presented to me by my senses.

(23) How does Descartes counter the errors of his bodily perceptions?

Refutation of the Dreaming Hypothesis. Descartes further restores confidence in bodily perceptions by setting aside the possibility that he is dreaming.

And I ought to set aside all the doubts of these past days as hyperbolic and ridiculous, particularly that very common uncertainty respecting sleep, which I could not distinguish from the waking state. For at present I find a very notable difference between the two, inasmuch as our memory can never connect our dreams one with the other, or with the whole course of our lives, as it unites events which happen to us while we are awake. And, as a matter of fact, if someone, while I was awake, quite suddenly appeared to me and disappeared as fast as do the images which I see in sleep, so that I could not know from where the form came nor where it went, it would not be without reason that I should deem it a ghost or a phantom formed by my brain [and similar to those which I form in sleep], rather than a real man. But when I perceive things as to which I know distinctly both the place from which they proceed, and that in which they are, and the time at which they appeared to me. And when, without any interruption, I can connect the perceptions which I have of them with the whole course of my life, I am perfectly assured that these perceptions occur while I am waking and not during sleep. And I ought in no wise to doubt the truth of such matters, if, after having called up all my senses, my memory, and my understanding, to examine them, nothing is brought to evidence by any one of them which is repugnant to what is set forth by the others. For because God is in no wise a deceiver, it follows that I am not deceived in this. But because the exigency of action often oblige us to make up our minds before having leisure to examine matters carefully, we must confess that the life of man is very frequently subject to error in respect to individual objects, and we must in the end acknowledge the infirmity of our nature.

(24) What is the fundamental distinction between perceiving things while awake and perceiving things while asleep?

SYNOPSIS. Descartes’ synopsis of the Sixth Meditation (initially presented at the opening of his Meditations) is as follows.

            Finally in the Sixth I distinguish the action of the understanding from that of the imagination; the marks by which this distinction is made are described. I here show that the mind of man is really distinct from the body, and at the same time that the two are so closely joined together that they form, so to speak, a single thing. All the errors which proceed from the senses are then surveyed, while the means of avoiding them are demonstrated, and finally all the reasons from which we may deduce the existence of material things are set forth. Not that I judge them to be very useful in establishing that which they prove, namely, that there is in truth a world, that men possess bodies, and other such things which never have been doubted by anyone of sense; but because in considering these closely we come to see that they are neither so strong nor so evident as those arguments which lead us to the knowledge of our mind and of God; so that these last must be the most certain and most evident facts which can fall within the cognizance of the human mind. And this is the whole matter that I have tried to prove in these Meditations, for which reason I here omit to speak of many other questions which I dealt incidentally in this discussion.

PREFACE TO THE READER

            As noted at the outset of this chapter, Descartes opened his Meditations with a “Preface to the Reader.” Since his discussion presupposes familiarity with the six Meditations themselves, the “Preface” is placed here in the present chapter.

ARGUMENTS IN HIS “DISCOURSE.” In his earlier Discourse on the Method (1637), Descartes also discusses the existence of God and the nature of the human soul. He explains that the earlier discussion in the Discourse was intentionally brief.

            I have already slightly touched on these two questions of God and the human soul in the Discourse on the Method of rightly conducting the Reason and seeking truth in the Sciences, published in French in the year 1637. Not that I had the design of treating these with any thoroughness, but only so to speak in passing, and in order to ascertain by the judgment of the readers how I should treat them later on. For these questions have always appeared to me to be of such importance that I judged it suitable to speak of them more than once; and the road which I follow in the explanation of them is so little trodden, and so far removed from the ordinary path, that I did not judge it to be useful to set it forth at length in French and in a Discourse which might be read by everyone, in case the feebler minds should believe that it was permitted to them to attempt to follow the same path.

(1) The Discourse was published in French, as opposed to Latin. What bearing did that have on Descartes’ decision to tone down his arguments in the Discourse?

CRITICISMS OF THE DISCOURSE. In the Discourse, Descartes requested that his readers point out errors in his reasoning. He presents and responds to two of the more important criticisms made.

            But, having in this Discourse on Method begged all those who have found in my writings somewhat deserving of censure to do me the favor of acquainting me with the grounds of it, nothing worthy of remark has been objected to in them beyond two matters. To these two I wish here to reply in a few words before undertaking their more detailed discussion.

Thinking as the Essence of the Soul. Although the objections are aimed at the Discourse, they can also be related to the line of reasoning in the Meditations. In Meditation Two, Descartes notes that thinking is the only quality which he can claim to possess. In Meditation Six, he states more strongly that thinking is the only quality which the soul possesses. The former is an epistemological claim, and the latter is an ontological claim. Descartes’ critics point out that the second claim cannot be inferred from the first.

            The first objection is that it does not follow from the fact that the human mind reflecting on itself does not perceive itself to be other than a thing that thinks, that its nature or its essence consists only in its being a thing that thinks, in the sense that this word only excludes all other things which might also be supposed to pertain to the nature of the soul. To this objection I reply that it was not my intention in that place to exclude these in accordance with the order that looks to the truth of the matter (as to which I was not then dealing), but only in accordance with the order of my thought [perception]. Thus my meaning was that so far as I was aware, I knew nothing clearly as belonging to my essence, except that I was a thing that thinks, or a thing that has in itself the faculty of thinking. But I will show hereafter how from the fact that I know no other thing which pertains to my essence, it follows that there is no other thing which really does belong to it.

(2) Descartes believes that in the Meditations he is sufficiently justified in concluding that the essence of the soul is thinking (an ontological claim) given that thinking is the only attribute which he knows he has (an epistemological claim). What, however, does he say his intention was in the Discourse (that is, “in that place”)?

The Idea of Infinite Perfection. The second objection again applies to the reasoning in the Discourse, but can also be related to the Meditations. In Meditation Three Descartes proves God’s existence based on the fact that he has an idea of infinite perfection in his mind.

            The second objection is that it does not follow from the fact that I have in myself the idea of something more perfect than I am, that this idea is more perfect than I, and much less that what is represented by this idea exists. But I reply that in this term idea there is here something equivocal, for it may either be taken materially, as an act of my understanding, and in this sense it cannot be said that it is more perfect than I; or it may be taken objectively, as the thing which is represented by this act, which, although we do not suppose it to exist outside of my understanding, may, none the less, be more perfect than I, because of its essence. And in following out this Treatise I will show more fully how, from the sole fact that I have in myself the idea of a thing more perfect than myself, it follows that this thing truly exists.

(3) What are the two senses of the word “idea” that Descartes distinguishes?

            In addition to these two objections I have also seen two fairly lengthy works on this subject, which, however, did not so much criticize my reasonings as my conclusions, and this by arguments drawn from the ordinary atheistic sources. But, such arguments cannot make any impression on the minds of those who really understand my reasonings. Further, the judgments of many are so feeble and irrational that they very often allow themselves to be persuaded by the opinions which they have first formed, however false and far removed from reason they may be, rather than by a true and solid but subsequently received refutation of these opinions. Thus, I do not desire to reply here to their criticisms in case of being first of all obliged to state them. I will only say in general that all that is said by the atheist against the existence of God, always depends either on the fact that we ascribe to God affections which are human, or that we attribute so much strength and wisdom to our minds that we even have the presumption to desire to determine and understand that which God can and ought to do. In this way all that they allege will cause us no difficulty, provided only we remember that we must consider our minds as things which are finite and limited, and God as a Being who is incomprehensible and infinite.

THE INTENDED AUDIENCE OF THE MEDITATIONS. Descartes concludes noting that the Meditations are not intended for the casual reader.

            Now that I have once and for all recognized and acknowledged the opinions of people, I at once begin to treat of God and the human soul, and at the same time to treat of the whole of the First Philosophy, without however expecting any praise from the vulgar and without the hope that my book will have many readers. On the contrary, I should never advise anyone to read it except those who desire to meditate seriously with me, and who can detach their minds from affairs of sense, and deliver themselves entirely from every sort of prejudice. I know too well that such people exist in a very small number. But for those who, without caring to comprehend the order and connections of my reasonings, form their criticisms on detached portions arbitrarily selected, as is the custom with many, these, I say, will not obtain much profit from reading this Treatise. And although they perhaps in several parts find occasion of caviling, they can for all their pains make no objection which is urgent or deserving of reply.

Replies to Objections. Descartes passed a manuscript of his Meditations onto his friend, Father Mersenne, who solicited comments from fellow scholars, including Thomas Hobbes. The comments were returned to Descartes. These, along with his lengthy replies -- several times longer than the meditations themselves -- were included in the second published edition of the Meditations (1642).

            And inasmuch as I make no promise to others to satisfy them at once, and as I do not presume so much on my own powers as to believe myself capable of foreseeing all that can cause difficulty to anyone, I will first of all set forth in these Meditations the very considerations by which I persuade myself that I have reached a certain and evident knowledge of the truth, in order to see if, by the same reasons which persuaded me, I can also persuade others. And, after that, I will reply to the objections which have been made to me by persons of genius and learning to whom I have sent my Meditations for examination, before submitting them to the press. For they have made so many objections and these so different, that I venture to promise that it will be difficult for anyone to bring to mind criticisms of any consequence which have not been already touched upon. This is why I beg those who read these Meditations to form no judgment upon them unless they have given themselves the trouble to read all the objections as well as the replies which I have made to them.

SUPPLEMENTARY SELECTIONS

THE COGITO IS NOT DEDUCED. As noted, a lengthy set of objections and replies was published along with the Meditations. One of the more important exchanges from the “Second set of Objections” concerned whether Descartes deduces the knowledge of his existence in the sense of a logical deduction.

Objection. [At the outset of Meditation 2] you are not yet certain of the aforesaid existence of God. Yet, according to your statement, you cannot be certain of anything or know anything clearly and distinctly unless previously you know certainly and clearly that God exists. Thus, you cannot clearly and distinctly know that you are a thinking thing, since, according to you, that knowledge depends on the clear knowledge of the existence of God, the proof of which you have not yet reached at that point where you draw the conclusion that you have a clear knowledge of what you are.

Reply. When I said that “we could know nothing with certainty unless we were first aware that God existed,” I announced in express terms that I referred only to the science of understanding such conclusions “as can recur in memory without attending further to the proofs which led me to make them.” Further, knowledge of the first principles is not usually called “science” by dialecticians. But when we become aware that we are thinking beings, this is a primitive act of knowledge derived from no syllogistic reasoning. He who says, “I think, hence I am, or exist,” does not deduce existence from thought by a syllogism. But by a simple act of mental vision, he recognizes it as if it were a thing that is known per se. This is evident from the fact that if it were syllogistically deduced, the major premise, “that everything that thinks is, or exists” would have to be known previously. But yet that has rather been learned from the experience of the individual, that unless he exists he cannot think. For our mind is so constituted by nature that general propositions are formed out of the knowledge of particulars.

(1) Why don’t we deduce the proposition “I exist”?

THE PINEAL GLAND. As seen in Meditation Six, Descartes believes that humans are composed of two distinct parts: a physical body which moves about in the physical world, and a nonphysical or spiritual mind which does the thinking. This dualism presents a problem for Descartes insofar as an explanation is needed as to how our minds and bodies interact in their separate realms. For example, when my hand touches something hot, this sensation is registered in my mind. Also, if my mind decides to remove my hand, this decision must be transferred to my body, which results in motor activity. Thus, Descartes needs an explanation of both sensory and motor communication between our spirit minds and physical bodies. In the following, from Part One of The Passions of the Soul (1649), Descartes argues that the pineal gland in the brain is the gateway between the two realms. (Section titles below are Descartes’.)

31. That there is a small gland in the brain in which the soul exercises its function more particularly than in the other parts. It is likewise necessary to know that although the soul is joined to the whole body, there is yet in that a certain part in which it exercises its functions more particularly than in all the others. And it is usually believed that this part is the brain, or possibly the heart. It is believed to be the brain because it is with it that the organs of sense are connected. And it is believed to be the heart because it is apparently in it that we experience the passions. But, in examining the matter with care, it seems as though I had clearly ascertained that the part of the body in which the soul exercises its functions immediately is in nowise the heart, nor the whole of the brain. Instead, it is merely the most inward of all its parts, namely, a certain very small gland which is situated in the middle of its substance and so suspended above the duct whereby the animal spirits in its anterior cavities have communication with those in the posterior. It is such that the slightest movements which take place in it may alter very greatly the course of these spirits. And, reciprocally, the smallest changes which occur in the course of the spirits may do much to change the movements of this gland.

(3) What are the two standard accounts of where the body and soul are connected?

32. How we know that this gland is the main seat of the soul. The reason which persuades me that the soul cannot have any other seat in all the body than this gland wherein to exercise its functions immediately, is that I reflect that the other parts of our brain are all of them double, just as we have two eyes two hands, two ears, and finally all the organs of our outside senses are double. And inasmuch as we have but one solitary and simple thought of one particular thing at one and the same moment, it must necessarily be the case that there must somewhere be a place where the two images which come to us by the two eyes, where the two other impressions which proceed from a single object by means of the double organs of the other senses, can unite before arriving at the soul, in order that they may not represent to it two objects instead of one. And it is easy to see how these images or other impressions might unite in this gland by the intermission of the spirits which fill the cavities of the brain. But there is no other place in the body where they can be thus united unless they are so in this gland.

(4) What reason does Descartes give for holding that the pineal gland is the gateway between the brain and body?

34. How the soul and the body act on one another. Let us then conceive here that the soul has its principal seat in the little gland which exists in the middle of the brain. For, from this spot it radiates forth through all the remainder of the body by means of the animal spirits, nerves, and even the blood, which, participating in the impressions of the spirits, can carry them by the arteries into all the members. Recall what has been said above about the machine of our body, that is, that the little filaments of our nerves are so distributed in all its parts, that on the occasion of the diverse movements which are there excited by sensible objects, they open in different ways the pores of the brain. This, in turn, causes the animal spirit contained in these cavities to enter in different ways into the muscles, by which means they can move the members in all the different ways in which they are capable of being moved. And also, recall all the other causes which are capable of moving the spirits in different ways and which suffice to conduct them into different muscles. Let us here add that the small gland which is the main seat of the soul is so suspended between the cavities which contain the spirits that it can be moved by them in as many different ways as there are sensible differences in the object.

(5) How does the soul receive perceptions from the body?

Further, it may also be moved in different ways by the soul, whose nature is such that it receives in itself as many different impressions, that is to say, that it possesses as many different perceptions as there are different movements in this gland. Reciprocally, likewise, the machine of the body is so formed that from the simple fact that this gland is differently moved by the soul (or by such other cause, whatever it is) it thrusts the spirits which surround it towards the pores of the brain, which conduct them by the nerves into the muscles, by which means it causes them to move the limbs.

(6) How does the soul send motor commands to the body?

THE AUTOMATISM OF ANIMALS. Descartes believed that, on earth, only humans have a dual spirit/body nature. Non-human animals have only bodies and are essentially automaton or biological robots which behave according to their internal biological programs. Thus, they do not think, even though they behave in ways which we might mistakenly take to reflect conscious thought. Descartes’ view was patently rejected by many of his contemporaries. In his article on Rorarius in the Historical and Critical Dictionary (1692), Bayle presents a long list of criticisms against Descartes’ theory. Even today Descartes’ view is the object of ridicule by animal rights advocates. Descartes’ reasoning is presented in the following letter to Henry More.

            ... the greatest of all prejudices we have retained from infancy is that of believing that animals [brutes] think. The source of our error comes from having observed that many of the bodily members of animals are not very different from our own in shape and movements. The mistake also comes from the belief that our mind is the principle of motions which occur in us, and that it imparts motion to the body and is the cause of our thoughts. Assuming this, we find no difficulty in believing that there is in animals a mind similar to our own. But, after thinking well upon it, I have made the discovery that two different principles of our movements are to be distinguished. The one is entirely mechanical and corporeal, and depends solely on the force of the animal spirits and the configuration of the bodily parts and may be called corporeal soul. The other is incorporeal, that is to say, mind or soul, which you may define a substance which thinks. I have inquired with great care whether the motions of animals proceed from these two principles or from one alone. Now, having clearly perceived that they can proceed from one only, I have held it demonstrated that we are not able in any manner to prove that there is in the animals a soul which thinks.

(7) What are the two sources of motion in organisms, and which apply to animals?

I am not at all disturbed in my opinion by those doublings and cunning tricks of dogs and foxes, nor by all those things which animals do, either from fear, or to get something to eat, or just for sport. I engage to explain all that very easily, merely by the conformation of the parts of the animals. Nevertheless, although I regard it as a thing demonstrated that it cannot be proved that the animals have thought, I do not think that it can be demonstrated that the contrary is not true, because the human mind cannot penetrate into the heart to know what goes on there, But on examining into the probabilities of the case, I see no reason whatever to prove that animals think, except that by having eyes, ears, a tongue, and other organs of sense like ours, it is likely that they have sensations as we do, and as thought is involved in the sensations which we have, a similar faculty of thought must be attributed to them. Now, since this argument is within the reach of everyone’s capacity, it has held possession of all minds from infancy.

(8) What is the most held reason for thinking that animals do think?

But there are other stronger and more numerous arguments for the opposite opinion, which do not so readily present themselves to everybody’s mind. For example, it is more reasonable to make earthworms, files, caterpillars, and the rest of the animals move as machines do, than to endow them with immortal souls.

            It is certain that in the body of animals, as in ours, there are bones, nerves, muscles, blood, animal spirits, and other organs which are given in such a manner that they can produce themselves without the aid of any thought. All the movements which we observe in the animals, as appears in convulsive movements, when in spite of the mind itself, the machine of the body moves often with greater violence, and in more various ways than it is accustomed to do with the aid of the will. Further, human beings are able to construct different automata in which there is movement without any thought. In as much as it is agreeable to reason that art should imitate nature, nature, on her part, might produce these automata, and far more excellent ones as the animals are, than those which come from the hands of people. Thus, there is no reason anywhere why thought is to be found wherever we perceive a conformity of bodily members like that of the animals. And it is more surprising that there should be a soul in every human body than that there should be none at all in the animals.

(9) What reasons does Descartes give for denying a thinking soul to animals?

But the principal argument to my mind, which may convince us that the animals are devoid of reason is this. Among animals of the same species, some are more perfect than others, as among people. This is particularly noticeable in horses and dogs, some of which have more capacity than others to retain what is taught them. All of them make us clearly understand their natural movements of anger, of fear, of hunger, and others of like kind, either by the voice or by other bodily motions. However, it has never yet been observed that any animal has arrived at such a degree of perfection as to make use of a true language. That is to say, they have not been able to indicate to us by the voice, or by other signs anything which could be referred to thought alone, rather than to a movement of mere nature. For the word is the sole sign and the only certain mark of the presence of thought hidden and wrapped up in the body. Now, all people, the most stupid and the most foolish, those even who are deprived of the organs of speech, make use of signs, whereas the animals never do anything of the kind. This may be taken as the true distinction between humans and animals.

(10) What is his main argument for denying thought to animals?

... It must, however, be observed that I speak of the thought of animals, not of their life, nor of their sensation. For I do not deny the life of any animal when making it consist solely in the warmth of the heart. I do not refuse to them feeling even, in so far as it depends only on the bodily organs. Thus, my opinion is not so cruel to animals as it is favorable to humans. I speak to those who are not committed to the extravagant position of Pythagoras, who held people under suspicion of a crime those who ate or killed animals.

(11) What specifically is Descartes denying to animals (that is, life, feeling, or thought)?