From The History of Philosophy: A Short Survey


James Fieser


Revised 9/1/2017


A. Introduction

B. Socrates

Socrates and the Sophists

The Socratic Dialectic Method

Wisdom and Self-Examination

Obedience to the State

C. Plato

Knowledge and the Forms

The Cave and the Divided Line

Soul: Dualism, Immortality, Three Parts, Virtues

Politics: Tradespeople, Guardians, Rulers

Art: Imitation, Education, Censorship

D. Aristotle

Logic: Syllogisms, Fallacies, Categories

Physics: Purpose, Natural Objects, Four Causes, Unmoved Mover

Metaphysics: Matter-Form, Substance-Accident, Potentiality-Actuality

Soul: Form of the Body and Three Types

Ethics: Desire-Regulating Virtues

Politics: Natural Rulers

Art: Imitation and Catharsis

D. Conclusion

Reading 1: Socrates on Trial (from Plato, Apology)

Reading 2: Plato’s Allegory of the Cave (from Plato, Republic)





With an ever-growing number of philosophers coming on the scene, the Greek-speaking territories were lively intellectual environments, particularly the city of Athens which was becoming the cultural center of the area. Within this philosophically energetic community, Greece’s three great philosophers emerged: Socrates, his student Plato, and his student Aristotle. At first each of these was just one among many active philosophers, but soon the substance and sophistication of their views made them towering figures, and they established schools of students who perpetuated their views.




Socrates (469–399 BCE) is famous for his dialectical method of questioning people. Born and raised in Athens, he was from a poor family, his father a stone mason and his mother a midwife. Socrates married and fathered three sons with his wife, a much younger and most difficult woman. It is not known by what method he supported himself and his family, although tradition has it that he followed in his father’s footsteps as a stone mason. In any event, he did not have much money, and spent his time dialoging with the young and old on moral issues—often in a very confrontational way. In market places, on the streets, at people’s homes: wherever people would listen, he’d engage them in discussion. His personal appearance was not particularly inviting; he dressed like a bum, had a snubbed-nose, cloudy-eyes, and a large mouth. Socrates lived in Athens during a critical time in its history. While the city was at the height of its cultural glory, it was besieged in a war lasting almost 30 years with the neighboring Greek city-state of Sparta. At its lowest point, 150,000 Athenean citizens encamped behind the city walls, fending off attacks.  At different times Socrates himself served in the Athenian army. Ultimately, Athens suffered a humiliating defeat, and in an effort to stabilize society, there was no room for a social troublemaker like Socrates who challenged Athenian traditions. He was charged with the crime of atheism and corrupting the youth, and when alienating himself further during his trial, he was found guilty and executed.

             In spite of Socrates’ historic fame, this is pretty much all that we know for certain about him—and even some of this might be folklore. Part of the problem is that he wrote nothing himself, and what we do know of his life and teaching comes largely from the writings of Plato, and to a lesser extent those of another student of his named Xenophon. In both cases these authors composed their works in a literary style that mixed historical facts about Socrates with fiction. This is most evident with Plato who composed his philosophical works in dialogue form, modeled after Greek plays of the time; in these he honors Socrates by making him the lead character. In these dialogues Socrates moves among a strange cast of politicians, aristocrats, and Sophists—most also based on historical figures. On the one hand, Plato deserves the highest praise for being the first to write in the form of a philosophical dialogue, thereby heightening the drama of a potentially tedious subject. On the other hand, this makes it almost impossible to know where the Socrates of history stops, and the Socrates of Plato’s imagination begins. Many scholars believe that Plato’s earlier dialogues reveal a bit more of the true Socrates than his later ones. Thus, in our study of Socrates here we draw out features of Socrates’ teaching from a couple of these early sources, most notably Plato’s Apology, which purports to be an account of the defense that Socrates gave at his trial.


Socrates and the Sophists

Socrates trial was held in Athens’ central market place, where spectators were shaded from the hot sun by cloth canopies. A jury of 501 citizens was chosen at random, and Socrates’ defense speech was timed by a water clock. As noted, Socrates was accused of atheism and corrupting the youth, both of which are linked to his assumed reputation as a Sophist. For decades Socrates had irritated influential Athenians with his endless haranguing, and, from their perspective, he was an annoying Sophist who held unconventional views about religion and morality, and used linguistic tricks to trap opponents. Thus, according to the charges against him, Socrates allegedly “inquired into things below the earth and in the sky and made the weaker argument appear the stronger.” Socrates was such a prominent debater and teacher within Athens that he was depicted in a play by Aristophanes called The Clouds. In one scene Socrates is sitting in a basket above the ground suspended by a rope. A visitor calls to him, and Socrates gruffly responds:


Socrates: Mortal, what do you want with me?

Visitor: First, what are you doing up there? Tell me, I beg you.

Socrates: I am navigating the air and contemplating the sun.

Visitor: So it’s not on the solid ground, but from the height of your basket that you look down on the gods, if indeed....

Socrates: I have to suspend my brain and mingle the subtle essence of my mind with the air, which is of similar nature, in order to clearly penetrate the things of heaven. I would have discovered nothing had I remained on the ground to consider from below the things that are above. For the earth by its force attracts the sap of the mind to itself. . . . So why have you come?

Visitor: I want to learn how to argue. I have borrowed money, and my merciless creditors do not leave me a moment’s peace. . . . I swear to the gods that I am ready to pay any fee you may name.

Socrates: By which gods will you swear? To begin with, the gods are not coins that have any value with us here. [Aristophanes, The Clouds]


In this one short exchange we find the essence of both accusations against Socrates. At his trial he denied that he was a Sophist since Sophists charged fees for their teaching, and Socrates taught for free. He also denied ever philosophizing about unconventional religious matters as depicted in Aristophanes’ play.

             Granted, then, Socrates was not a money-charging Sophist like Protagoras or Gorgias. But what exactly was he doing? At his trial he explained that he was on a moral quest to discover wisdom. It all started, he explained, when a young man was interested in finding out who the wisest person alive might be, and went to a temple at the nearby town of Delphi and asked the Prophetess there if she knew. She replied that was Socrates. When Socrates got word of what the Prophetess said, he attempted to prove her wrong by finding someone wiser. So, he approached famous politicians, poets and tradespeople, but he discovered that none could live up to their reputations. The politicians weren’t as wise as they claimed; the poets didn’t know the meaning of their own poems, and were simply mouthpieces for the gods; the tradespeople thought they knew everything, just because they were good at their specific crafts. Socrates explains what he learned from this exercise:


I asked myself on behalf of the oracle, whether I would like to be as I was, neither having their knowledge nor their ignorance, or like them in both. I answered to myself and to the oracle that I was better off as I was. . . . God only is wise; and by his answer he intends to show that the wisdom of men is worth little or nothing; he is not speaking of Socrates, he is only using my name by way of illustration, as if he said, He, O men, is the wisest, who, like Socrates, knows that his wisdom is in truth worth nothing. [Plato, Apology]


Thus, on the plus side, through this exercise he discovered that wisdom consists of recognizing that one knows nothing. On the minus side, through his critical inquiries he antagonized virtually everyone in town.


The Socratic Dialectic Method

Socrates’ method of teaching involved his dialoguing with people in a rather unique way; the technical term for this is dialectics, or more specifically, the Socratic dialectic method. There are three features of this method. First, he would typically begin by asking his student—or debating opponent—a question like “What is justice?” or “What is religious piety?” When the student would answer, Socrates would invariably find the response to be trivial, unclear, or just plain wrong. Second, he would refute the student’s answer by exposing absurdities with it. The refutation would usually begin slowly and subtly by getting the student to agree to a seemingly innocent point. Then Socrates would make the student draw out the implications of the innocent statement, which would end up contradicting the student’s original answer. Third, throughout the exchange, Socrates would typically heap insincere praise upon the student, such as by saying “That’s an excellent answer!” or “Good lord I think you’ve solved the problem!” This aspect of the method is called Socratic Irony. All in all, the dialectic process would be a humbling one for Socrates’ students, and even a humiliating one for his opponents who were rich and powerful community leaders.

             There’s no better illustration of Socratic dialectics in action than at his trial when, quite strangely, Socrates begins interrogating his accuser. The opponent in question, a religious fanatic named Meletus, is the one who officially charged Socrates with atheism and corrupting the youth. Socrates then uses the dialectic method against Meletus to refute both of these charges. In the following, Socrates challenges the accusation that he corrupts the youth. He begins by asking Meletus the basic question “who improves the youth?”


            Socrates: Tell the judges who is the improver of the youth; for you must know, since you have taken the pains to discover their corrupter . . .

            Meletus: The laws.

            Socrates: But that, my good sir, is not my meaning. I want to know who the person is, who, in the first place, knows the laws.

            Meletus: The judges, Socrates, who are present in court.

            Socrates: Do you mean to say, Meletus, that they are able to instruct and improve youth?

            Meletus: Certainly they are.

            Socrates: All of them, or some only and not others?

            Meletus: All of them.

            Socrates: By the goddess Hera, that is good news! There are plenty of improvers, then. And what do you say of the audience: do they improve them?

            Meletus: Yes, they do.

            Socrates: And the senators?

            Meletus: Yes, the senators improve them.

            Socrates: But perhaps the members of the assembly corrupt them, or do they too improve them?

            Meletus: They improve them.

            Socrates: Then every Athenian improves and elevates them, all with the exception of myself, and I alone am their corrupter. Is that what you affirm?

            Meletus: That is what I stoutly affirm. [Ibid]


             The aim of the entire exchange above was to corner Meletus into asserting the extreme view that everyone in Athens improves the youth while Socrates alone corrupts them.  Note the ironic statement above where Socrates says to Meletus “By the goddess Hera, that is good news!” Socrates then goes into refutation mode by having Meletus agree to a very simple question: “Does only one person harm horses while everyone else does them good?” Socrates’ point is that in no area of life is there only one person who harms while everyone else does good: not with horses, or dogs, or whatever. This contradicts, and thus refutes, Meletus’ earlier claim that everyone in Athens improves the youth while Socrates alone corrupts them.


Wisdom and Self-Examination

While Socrates may have won this particular logical battle with Meletus, he did so with argument tactics that quite likely reinforced jurors’ suspicions that he was a troublesome Sophist. Indeed, the majority of the jury found him guilty. At that point in the proceedings, Socrates could suggest alternative punishments to the overly-zealous death sentence that Meletus was requesting for him. There was a standard list of lesser punishments that they were expecting Socrates to select from, such as paying a substantial fine, or promising to stop making trouble, or imprisonment, or permanently relocating to another city. The alternative punishment that Socrates recommended to the jury is about as bizarre as one can imagine: he suggested that he should receive a reward in view of the positive impact that his actions had on society. Chief among his accomplishments, he argued, was persuading people to seek virtue and wisdom before pursuing private interests. The specific reward that Socrates recommended was commonly reserved for visiting political dignitaries and Olympic champions, and, by our standards today, it would be like throwing someone a parade or awarding someone a medal of honor.

             In addition to recommending a reward, Socrates explained why he did not request one of the standard alternative punishments, or simply staying quiet from thereon. He couldn’t hold his tongue, he explained, because it would be disobeying a command by God: “the greatest human good is daily discussion about virtue (and of those other things about which you hear me examining myself and others), and that the unexamined life is not worth living.” In this quotation we find Socrates’ most famous statement, that “the unexamined life is not worth living.” In a nutshell, true wisdom consists of continually examining one’s moral values through discussion with others. While at the close of his defense Socrates did offer to pay a fine, it was too late. He sufficiently antagonized the jury and they gave him the death sentence.

             Such is the picture that Plato gives us of Socrates at his trial: a man of wisdom devoted to his moral mission, come what may. But Xenophon, another of Socrates’ students adds perhaps a more human side to the story. Socrates was 70 years old by this time, and prior to the trial, according to Xenophon, Socrates told others that a death sentence at his age might not be such a bad thing:


If my age is still to be prolonged, I know that I cannot escape paying the penalty of old age, in increasing dimness of sight and dullness of hearing. . . . It may be, you know, that God out of his great kindness is intervening in my behalf to suffer me to close my life in the ripeness of age, and by the gentlest of deaths.  [Xenophon, Apology]


Obedience to the State

The drama of Socrates’ fate did not end with his trial. During a month’s delay before his scheduled execution, he continued to greet and converse with friends while in prison. In another early dialogue of Plato’s called Crito, we find Socrates in prison with a wealthy student of his named Crito. Crito had bribed the prison guard to allow Socrates the chance to escape, and Socrates explains that he is morally obligated to follow the decision of the jury. The central issue that he debates with Crito concerns the level of obedience that we have to the state. Although Socrates was undoubtedly a social rebel during his life, on the issue of political obedience he takes a very conservative position. The dialogue opens with Crito giving Socrates several of arguments for why he should escape. Crito himself does not want to lose Socrates as a friend, and he fears that people will think poorly of him for not having helped Socrates. Further, Crito argues that by remaining in prison Socrates is conceding defeat to his enemies within Athens, and is also deserting his Children. Socrates rejects all of Crito’s reasons, since they merely express the opinions and values of the masses. In the end, he argues, the only opinion that should matter is that of the expert, the one who is skilled in the particular subject of political obedience. That expert, according to Socrates, is none other than the Laws of Athens themselves.

             Continuing in this dialogue, Socrates imagines that the Laws of Athens took on human form so that Socrates and the Laws could debate the issue. The Laws then offer two specific arguments for political obedience. The first is a debt of gratitude argument that focuses on the obligation that we have to our parents for rearing and educating us. Since society also performs the same function of nurturing and educating us, we owe society the same obedience that we do our parents. In the words of the Laws, “in disobeying us he is disobeying his parents” (Crito). The second is a social contract argument that focuses on an agreement that we make with a city when we live in it. At any time we could pick up and leave our city of residence, but by choosing to remain there we are implicitly agreeing to abide by the laws of the city. By staying, each person “has entered into an implied contract that he will do as we command him” (ibid). For both of these reasons, then, Socrates is duty-bound to obey the laws, and thus must accept the verdict of the jury which was acting under the authority of the Law of Athens.

             Thus, Socrates remained in prison within the company of Crito and other devoted students while he was executed by drinking a poison from the hemlock plant, which results in a death through paralysis of the central nervous system. In the following, Plato provides a moving description of Socrates’ death:


Raising the cup to his lips, quite readily and cheerfully he drank off the poison. . . . The man who gave him the poison now and then looked at his feet and legs; after a while he pressed his foot hard, and asked him if he could feel; Socrates said “No.” . . . [The man] said, “When the poison reaches the heart, that will be the end.” He was beginning to grow cold about the waist when he uncovered his face (for he had covered himself up), and with his last words said, “Crito, I owe a chicken to Asclepius; will you remember to pay the debt?” Crito said, “The debt shall be paid; is there anything else?” There was no answer to this question. In a minute or two a movement was heard, and the attendants uncovered him. His eyes were set, and Crito closed his eyes and mouth. Such was the end of our friend, concerning whom I may truly say, that of all the men of his time whom I have known, he was the wisest and justest and best. [Plato, Phaedo]


The whole episode was traumatic for all of Socrates’ followers, and many, such as Plato, committed themselves to carrying on the vision of philosophy that Socrates established.




The focus of Plato’s philosophy is his view that reality is located in a spirit-realm containing perfect models of objects and concepts that he calls Forms. Born into one of the oldest, wealthiest and most influential families in Athens, the man we know historically as “Plato” (428–348 BCE) was at birth named Aristocles, after his grandfather. His nickname, Plato, meaning “broad,” could possibly have come from his wrestling-trained physique or style. At first Plato seemed destined to become a politician since he had several family members who were prominent public figures. In particular, a cousin and uncle, along with others known as the “Thirty Tyrants,” became self-appointed dictators after overthrowing the government at Athens and they invited Plato to join them. Once seeing their unethical and violent practices, however, Plato refused. The next year they were deposed. After the execution of his beloved teacher Socrates, Plato left Athens, traveling for a number of years through Egypt and Italy, studying philosophy. Determined to pass on the teachings of Socrates that had so inspired his own life, in 387 BCE Plato returned to Athens, acquired a house and gardens, and opened a school of philosophy and science, with classes held in a gymnasium. The school later became known as the Academy and is thought to have been the first university—which continued in operation for 900 years when finally shut down by a Roman emperor in 529 CE. While Plato was certainly the centerpiece of the Academy, he fostered an open range of critical inquiry, and there was no official list of Platonic doctrine that students were required to adopt. It was at the Academy that Plato spent the rest of his life teaching and writing, with the exception of two trips to Sicily where he hoped to establish a perfect society. Both visits ended disastrously, and on the second he was held captive and escaped only with the help of some friends.

             We already noted that Plato wrote his philosophy in the form of dialogues with Socrates as the main spokesperson. In view of the fact that only scattered sentences of the Presocratic philosophers have come down to us, the number of surviving writings that we have of Plato is remarkable—around 25 dialogues topping 1,500 total pages in modern printed editions. Scholars believe that Plato’s own philosophical views are best represented in his later dialogues, where, again, they are presented by the Socrates character. One of the longest and most famous dialogues expressing Plato’s views is The Republic; while it focuses particularly on the notions of political justice and the perfect society, it touches on virtually every component of Plato’s thought.


Knowledge and the Forms

The starting point for Plato’s philosophy is a distinction that he frequently makes between knowledge and opinion. To the extent that we are all interested in learning new things, we certainly would prefer to know the truth of something, rather than just have an opinion about it. Plato was especially turned off by the relativism of the Sophists, as expressed in Protagoras’s view that “Man is the measure of all things,” and this set him on a quest for a firm foundation of knowledge. Many of the ideas we have are fluctuating, but, he argues, these are “a matter of opinion, and not as a matter of knowledge” (Republic, Bk. 5). Occasionally, however, we see absolute and eternal truths like justice and beauty for what they really are, and this is genuine knowledge. The main points of difference between knowledge and opinion are that opinion is changeable, it may be true or it may be false, it is not backed by good reasoning, and it is the result of mere persuasion. By contrast, knowledge is enduring, it is always true, it is backed by good reasoning, and is the result of instruction.

             Thus, Plato had an especially optimistic conception of knowledge, and he hoped to reject the opinionated relativism of the Sophists. But there’s something even more dramatic in Plato’s view of knowledge that’s reflected in his statement that “those who see the absolute and eternal and immutable may be said to know” (ibid). That is, there is an eternal reality that underlies genuine knowledge; that reality is the realm of the Forms. Plato used two Greek terms to refer to these abstract entities—eidos and ideos—which past scholars translated as “ideas”. But using the English word “ideas” was misleading since Plato was never referring to something inside a person’s mind, but instead to some objective feature in the world outside of our heads. Scholars now prefer to translate both Greek terms as “form” in the sense of a perfect pattern, model, or blueprint. Think of the Forms like this. Down here on earth, everything is imperfect and subject to decay and destruction. There are, for example, lots of tables, but each one is flawed in some way. However, in a higher spirit-like realm there are perfect versions of all of these things—or Forms as Plato calls them. There are perfect Forms of tableness, perfect Forms of mathematics, perfect Forms of moral concepts. Everything down here on Earth is just a cheap copy of the perfect Forms, and it takes a special act of the intellect to rise above this frail world of appearances into the true realm of knowledge in the Forms. A story relates that once Plato was lecturing about the Forms and using nouns like “tableness” and “cupness” to refer to them. A critic interrupted him and said, “I see a table and a cup, but I see no tableness or cupness.” Plato responded, “That is understandable since you have eyes by which you can contemplate a cup and a table, but you don’t have intellect by which you can see tableness and cupness.”

             There are four key features of his theory of the Forms. First, the Forms are immaterial: they are non physical spirit-like entities that, for Plato, exist somewhere in the center of the universe. The universe, then, has two tiers containing a lower physical level of ordinary things, and a higher spirit level of the Forms that contains a vast number of perfect abstract objects. Second, particular objects in the physical realm participate in the Forms and are what they are by virtue of this participation. Socrates was a just person because he participated in the form justice. A billiard ball is well-made if it participates in the perfect from of sphericalness. Conversely, when things in the world are defective, it is because they fail to participate in the perfect Forms, such as an unjust person or a lop-sided billiard ball. Third, there is a highest form which is that of perfect goodness, which Plato simply calls the Good. All good things here on earth participate in the Good, whether it’s a good person or a good billiard ball. Similarly, all of the other Forms such as justice or sphericalness participate in the Good: all Forms are perfect, and they get their perfection by participating in the Good itself.

             Fourth, knowledge of the Forms is acquired through intuitive recollection. We obviously can’t travel up to the realm of the Forms and experience them directly. Plato explains that we remember them from a previous life when our souls before birth had a more direct experience of them, with some souls seeing them more clearly than other souls. In our lives down here on earth, we do not necessarily recall each form one at a time. Rather, a single recollection may unleash a flood of knowledge about the Forms:


The soul, as being immortal, and having been born again many times, and having seen all things that exist, whether in this world or in the world below, has knowledge of them all. It is no wonder that it should be able to call to remembrance all that it ever knew about virtue, and about everything. For, all nature is similar, and the soul has learned all things. Thus, there is no difficulty in the soul drawing out and learning all things from a single recollection, so long as a person is strenuous and does not faint. All inquiry and all learning is simply recollection. [Meno, 81 c-d]


Strictly speaking, then, knowledge of the Forms can neither be taught nor learned. No philosopher, not even Socrates, can “teach” someone knowledge of the Forms. The best that a teacher can do is help that person recollect the knowledge he had of the Forms in a previous life. Plato boldly illustrates this in one of his dialogues where the Socrates character helps an uneducated slave boy solve a complex mathematical puzzle. The puzzle is how one might double the area of a square. Through a series of probing questions posed by the Socrates character, the boy arrives at a solution (i.e., draw a second square around the first such that the midpoints on the sides of the second touch the corners of the first). This shows that everyone has access to knowledge of the Forms, and it just takes the right teacher to draw this knowledge out of us.

             Plato’s notion of the Forms was inspired by mathematics, a subject he took so seriously that at a sign at the entrance to his Academy read “Let no one enter here who is ignorant of geometry.” When we look at numbers and mathematical relations, such as 1+1=2, they seem to be timeless concepts that never change, and apply everywhere in the universe. Humans do not invent numbers, and humans cannot alter them. The eternal and unchanging character of mathematical relations, then, is explained by the fact that they are perfect and unchanging Forms. For Plato, the manner in which we gain mathematical knowledge is a model for all knowledge.

             Sometimes Plato simply assumes the existence of the Forms, and other times he offers arguments for their existence, two of which are especially important. The first is an argument for the Forms based on knowledge. As we’ve seen, Plato draws a basic distinction between knowledge and opinion: knowledge is infallible and unchanging, opinion is fallible and changing. Genuine knowledge must be grounded in some source that is enduring and unchanging, and those are the Forms. Laid out more formally, the argument is this:


1. Knowledge is enduring and true.

2. This knowledge cannot be about the ever-changing world revealed through the senses.

3. Therefore, it must be about another world, one that endures, which is the world of the Forms.


The second argument for the Forms is based on general names that we use when referring to a collection of things. For example, there are many tables, but we use a single term to refer to them all, and that single term stands for the Form of the table. Plato makes this point here:


We are in the habit of positing a single Form for each set of many things to which we give the same name. . . . Let us take any common example: there are beds and tables in the world—plenty of them. . . . But there are only two Forms of them, one the idea of a bed, the other of a table. . . . And the maker of either of them makes a bed or he makes a table for our use, in accordance with the Form. That is our way of speaking in this and similar situations. But no artificer makes the ideas themselves:  how could  he? [Republic 10, 596]


The central point of the argument is that if there is a set of things all of which go by the same general name (e.g., table), then there is a Form for that set.


The Cave and the Divided Line

In the Republic, Plato uses two analogies to illustrate the various levels of reality. First is his famous allegory of the cave. Picture a group of people imprisoned in a subterranean cavern, which opens to the daylight by a long, wide passage. They are chained with their backs to a fire looking at shadows thrown by fire onto the wall in front of them—shadows of people and other figures that pass behind them. These people represent the condition of those who see nothing but the shadows of realities in the lower physical realm. If one of these prisoners should be freed from his chains, turns around and walk towards the light, at first he would be dazzled by the glare and unable to see clearly, but eventually he would realize that what he previously took for realities were nonentities. If he were brought up out of the cave into the light of day, he would soon be aware of the real objects and know that what he had previously beheld in the cave were only shadows, illusions.  Plato writes,


He will need to grow accustomed to the sight of the upper world. And first he will see the shadows best, next the reflections of men and other objects in the water, and then the objects themselves. Then he will gaze upon the light of the moon and the stars and the glittery heaven; he will see the sky and the stars by night better than the sun or the light of the sun by day. Last of all, he will be able to see the sun, and not mere reflections of it in the water, but he will see it in his own proper place. [Republic, 7]


Each discovery represents a new stage in the pursuit of wisdom; each stage is also painful since it requires staring at brightly illumined objects. Remembering his previous state in the cave, he would pity those who were still within it. But when returning to explain the truth of things to them, they wouldn’t take too kindly to him. Indeed, the unenlightened may even want to kill him as they did Socrates. All this represents the education of the philosopher: ascending out of the cave with great difficulty, gradually adjusting one’s eyes to the light, and ultimately seeing objects as they are in themselves. It is no surprise, Plato says, that “those who attain to this heavenly vision are unwilling to descend again to human affairs.” The allegory of the cave is rich in metaphor, and, in addition to explaining the realm of the forms, it says a lot about the general quest for human knowledge. Ignorance entraps us, and much of what we believe in is unreal. Further, when we finally attempt to escape from our ignorance and achieve true knowledge, the task is a very difficult one.

             Plato’s second analogy, that of the divided line, is a bit more detailed. Imagine that we took a 20 inch line and broke it into two pieces, one representing the physical realm and the other representing the realm of the Forms. Suppose, then, we broke each of these in half. Here are the four segments and what they represent:





Visible physical world of appearance illuminated by the sun (four inches total)

Segment 1 (one inch): lower physical reality (e.g. triangular shadow of a pyramid)

Segment 2 (three inches): higher physical reality (e.g., triangular side of a pyramid)

Intelligible spiritual world of knowledge illuminated by the Good (16 inches total)

Segment 3 (four inches): lower Forms (e.g., geometrical triangle)

Segment 4 (twelve inches): higher Forms (e.g., forms of justice, beauty)


The varying lengths of the line segments represent the varying degrees of truth in the respective levels of the universe. Plato believes that the visible world is less real than the intelligible world of the Forms; so, the line segments pertaining to the visible world are shorter than those of the intelligible world. He describes here the two components of the visible world:


Compare the subdivisions in respect of their clearness and want of clearness, and you will find that the first segment in the visible realm consists of images. And by images I mean, in the first place, shadows, and in the second place, reflections in water and in solid, smooth and polished bodies and the like. . . . Imagine, now, the second segment, of which this is only the resemblance, to include the animals which we see, and everything that grows or is made. . . . Would you not admit that both the segments of this division have different degrees of truth, and that the copy is to the original as the realm of opinion is to the realm of knowledge? [Republic, 6]


Segment 1 – the lowest level of reality – consists merely of shadows and reflections of things. For example, suppose that you visited the Great Pyramid of Giza in Egypt. Standing in front of it you would see a large triangular shadow of it on the ground, which would only be a distorted image of the real Pyramid. The real Pyramid itself is a physical thing that is part of segment 2. But just as shadows are cheap copies of physical objects, so too is the entire visible world a cheap copy of the intelligible world. Each side of the Pyramid is triangular, but none of those triangles are perfect. The edges are worn down over time, and, even when first built, there still would have been minute irregularities in its stone construction.

             Moving on to segments 3 and 4, like the visible world, the intelligible world also has a lower and higher level of reality. The lower level – line segment 3 – consists of perfect mathematical forms and equations. It is here that you would find the perfect formula of a geometrical triangle that human engineers might use when constructing a pyramid on earth. I would include all the calculations about stress points, and other mathematical components. As Plato sees it, the engineer has his vision set on the realm of the Forms, and not on visible physical objects. Segment 4 of the divided line represents the highest Forms, such as the essential nature of a pyramid monument, that is the ideal model of any pyramid on earth, whether in Gaze Egypt, or Memphis Tennessee. It is in segment 4 that all moral forms are contained, such as justice and temperance. Like the engineer, the moral person must also set his vision on that realm.

level of reality: the Good. We all seek the Good and, like the sun, the Good illuminates everything that we know.

             At the close of his discussion, Plato explains that there are four mental faculties that enable us to grasp the four levels of reality as represented by the divided line:


Corresponding to the four divisions, let there be four faculties in the soul—reason answering to the highest, understanding to the second, belief to the third, and imagination of shadows to the last—and let there be a scale of them, and let us suppose that the several faculties have clearness in the same degree that their objects have truth. [Republic, 6]


The weakest mental faculty – imagination – is responsible for detecting the images of shadows and reflections. The next faculty – belief– allows us to detect physical objects. For Plato, the exercise of these two faculties amount to nothing better than opinion, such as my opinion that I can sit on the chair in front of me without it collapsing. By contrast, knowledge is restricted to the domain of the Forms. Knowledge of the lower Forms is understanding, and knowledge of the Good is reason.


Soul: Dualism, Immortality, Three Parts, Virtues

The scientific study of psychology emerged rather recently, at the close of the nineteenth-century. However, philosophers from Presocratic times onward have speculated about the nature of the human mind—or soul as it was called in Greek times. Plato’s account of the soul is undoubtedly one of the most influential in the history of philosophy, and its impact is felt even today. There are four components to his theory: (1) body-soul dualism, (2) the immortality of the soul, (3) the three-part division of the soul, and (4) the cardinal virtues.

             Let’s begin with his body-soul dualism. We’ve already seen that Plato’s theory of the Forms depicts the universe as having two different levels of reality: the physical realm and the realm of the Forms. This is a type of matter-spirit dualism, where the material component of the universe is the changing physical realm of appearances, and the spirit realm is the unchanging realm of the Forms. When turning to his analysis of human nature, we see a parallel kind of dualism: we are made of both a physical body and an immaterial spirit. The soul, though, is the vastly superior component within us. Our bodies and all the desires that they produce are obstacles to knowledge and immortality. In a sense, the body entombs the soul, and death releases the soul from bodily limitations. In the following, Plato graphically describes the ways in which our bodies cause us troubles:


While we are in the body, and while the soul is infected with the evils of the body, our desire will not be satisfied. And our desire is of the truth. For the body is a source of endless trouble to us because of the mere requirement of food. It is liable also to diseases which overtake and hinder us in the search after true being. It fills us full of loves, lusts, fears, fancies of all kinds, endless foolishness, and in fact, as people say, it takes away from us the power of thinking at all. What is the source of come wars, and fighting, and factions? The body and the lusts of the body. Wars are occasioned by the love of money, and money has to be acquired for the sake and in the service of the body. [Phaedo]


Lusts of the body, he explains are the source of so many of life’s woes, such as wars which are driven by a desire for wealth. Our bodies also distract us from inquiring after truth, and, ultimately, we will attain true wisdom only after death when we shed our bodies:


Experience shows that if we would have pure knowledge of anything, we must leave the body. The soul by herself must observe things in themselves. Then we shall attain the wisdom which we desire, and of which we say that we are lovers, not while we live, but after death. If while in company with the body, the soul cannot have pure knowledge, one of two things follows: either knowledge cannot be attained at all, or, if at all, only after death. For then, and not till then, the soul will be parted from the body and exist in herself alone. [Ibid]


The best we can do now, he argues, is resist the cravings of the body, keep ourselves pure, and look forward to the time when death releases us and we can commune with pure truth. We will then be able to see “the clear light everywhere, which is no other than the light of truth” (ibid).

             The second aspect of Plato’s theory of the soul is that it is immortal. Unlike our bodies which will die and decay, the soul, Plato believes, is immortal, and he offers various arguments in proof of this. One argument for the soul’s immortality is from the unchanging Forms: the soul resembles the unchanging Forms and, thus, like the Forms themselves the soul is immortal. He makes this argument here:


When the soul and the body are united, then nature orders the soul to rule and govern, and the body to obey and serve. Now consider which of these two functions is more like the divine, and which is more like the mortal. Doesn’t the divine appear to you to be that which naturally orders and rules, and the mortal that which is subject and servant? . . . The soul is in the very likeness of the divine, and immortal, and intelligible, and uniform, and indissoluble, and unchangeable. By contrast, the body is in the very likeness of the human, and mortal, and unintelligible, and multiform, and dissoluble, and changeable. . . . If this is true, then isn’t the body susceptible to speedy dissolution, and is not the soul almost or altogether indissoluble? [Ibid]


Laid out more formally, the argument is this:


1. Material things come into existence and go out of existence.

2. Forms such as beauty and goodness are eternal and unchanging.

3. The soul is more like the Forms than it is like material things.

4. Therefore, the soul is eternal and unchanging.


             A second argument that Plato offers for the immortality of the soul is from self-motion. While the argument is a little tricky, it begins with a common assumption of his day that the human body does not move itself, but instead is prodded into motion by the soul. Sometimes our bodies might move from outside forces, such as when I ride in a car. However, the most important bodily movements that I make are produced inside of me by my soul, without any interference from outside forces. When my soul moves my body, then, my soul itself is a self-moving thing: it triggers bodily motion all by itself. Plato continues arguing that there is something special about self-motion: since it is uncreated by any outside force, it must be immortal. It is immortal in the sense that it has no beginning and cannot be destroyed. He states this here:


Only the self-moving, never leaving self, never ceases to move, and is the fountain and beginning of motion to all that moves besides. Now, the beginning is uncreated, for that which is created has a beginning; but the beginning is created of nothing, for if it were created by something, then the created would not come from a beginning. But if it is uncreated, it must also be indestructible; for if beginning were destroyed, there could be no beginning out of anything, nor anything out of a beginning; and all things must have a beginning. [Phaedrus, 245d-e]


Since self-moving things are eternal, and the soul is self-moving, the soul then must be eternal. He draws this conclusion here:


But if the self-moving is proved to be immortal, he who affirms that self-motion is the very idea and essence of the soul will not be put to confusion. For the body which is moved from without lacks a soul. However, that which is moved from within has a soul, for such is the nature of the soul. If this is true, must not the soul be the self-moving, and therefore of necessity uncreated and immortal? [Ibid]


Presented more formally, the argument for the immortality of the soul from self-motion is this:


1. If something is self-moving it is immortal, since self-motion is uncreated and that which is uncreated is immortal.

2. The soul is self-moving, since it moves the body from within (rather than the body moving from an outside force).

3. Therefore, the soul is immortal.


             The third element of Plato’s theory of the soul is that the soul has three parts to it. We regularly see cartoon images of a man trying to make a decision, such as eating a high calorie slice of cake. On one shoulder a tiny devil says “Go on, eat it, it will make you happy!” On the other shoulder a tiny angel says “Don’t eat it, it will make you gain weight!” The man then has to judge between the two. This parallels Plato’s account of the three parts of the soul: a bad part, a good part, and a third part that controls the impact of the first two. Using an analogy, he explains that the three parts are related to each other like a charioteer driving two horses, one of a good and the other of a bad nature. First, he describes the good horse:


The right-hand horse is upright and cleanly made. He has a lofty neck and a curved nose; his color is white, and his eyes dark; he is a lover of honor and modesty and temperance, and the follower of true glory; he needs no sting of the whip, but is guided by word and gentle warning only. [Ibid]


The good horse is a high-energy creature that is motivated by honor and other noble goals, and anxious for victory. The problem, though, is that if it had its way it would become arrogant and hot-tempered. Next, the bad horse:


The other is a crooked and lumbering animal, put together every which way. He has a short thick neck; he is flat-faced and of a dark color, with grey and blood-shot eyes. He is the companion of insolence and pride, shag-eared and deaf, barely yielding to whip and spur. [Ibid]


The bad horse is motivated by pleasures of every sort. If the bad horse always got its way, the results would be disastrous and lead to over-indulgence in every area of desire. The job of the charioteer is to be in charge of both horses, and make reasoned judgments about which horse to hold back at which time. He describes the role of the charioteer in a situation in which the charioteer sees a woman that he is in love with. The bad horse tries to jump on the woman, while the good horse tries to ignore her. The charioteer decides to behave himself, so he pulls back the reins forcing both horses into submission. At a later time, though, the charioteer decides to romance the woman, and he controls the horses differently.

             The fourth and final aspect of Plato’s theory of the soul involves what are now called the four cardinal virtues. This draws directly on his theory of the three-part division of the soul. The charioteer analogy describes how each part of the soul each play a role when making difficult choices. However, for Plato, there’s an important step we need to take to assure that the whole chariot will always run smoothly. We need to develop good habits that keep each aspect of the soul in line. These good habits are virtuous character traits that we are taught when young and continue to develop as we mature in life. Specifically, the four cardinal virtues are temperance, courage, wisdom, and justice. Temperance restrains the bad horse. It has us control our basic desires and natural impulses towards food, lust, and any other pleasurable drive that we might have. Courage restrains the noble horse, and it helps control the heroic parts of our personalities. We don’t want to thoughtlessly rush into danger when trying to rescue someone, or act arrogant about how courageous we are. Wisdom guides the charioteer, and helps the rational part of our soul make delicate judgments about right way to live. Finally justice helps you integrate all three parts of our souls personality—the bad horse, the noble horse, and the charioteer—so that each part performs precisely as it should in the right situation. The type of justice he describes here is for the proper functioning of the individual person. In his political philosophy, though, he describes the broader notion of justice that involves society as a whole. For Plato, the three parts of our soul are so intertwined that the four cardinal virtues are a package deal: if you have one virtue you also have the others, and if you lack one you also lack the others.


Politics: Tradespeople, Guardians, Rulers

Plato’s Republic is one of history’s great works of political philosophy, describing a perfect society that is ruled by a philosopher who has knowledge of the Forms. The work opens with an attack on a common skeptical view of social justice, namely that justice is merely a convention created by those in power and, essentially, that might makes right. This is precisely the kind of relativist view of justice held by Sophists; for them there is no absolute or independent standard of justice and, to the extent that “man is the measure of all things,” the person in power is the one who creates the standard of justice of the day. Plato opposes this, and instead argues that there is an ideal conception of justice—a form of justice—that is eternal and unchanging, and is the standard for societies to follow.

             If justice isn’t simply a matter of might making right, what then is it? For Plato justice is the harmonious relation between the parts of the community where each person fulfills his or her own role. He encapsulates this with the simple definition that justice is “each doing his own.” All parts of society must work together like all the parts of a giant human being. There is a political body in which each part performs its own critical task. Plato argues that there are three main parts of society that parallel the three parts of the individual human soul. First, there are trades-people—farmers, carpenters, clothiers, merchants—who provide for society’s basic needs. This part of society is the lowest and corresponds with the bad horse that is driven by desires. Next there are the guardians who protect society from outside attackers. This corresponds with the good horse that is driven by an energetic drive for honor. The living conditions of the guardians are very unusual because of the unique role they play. The guardians, both men and women, live together in one large family with no marriages or private property. They sleep in communal barracks, have romantic relations with anyone they prefer, and children are raised separately from adults.

             Finally there are the rulers who are selected from among the best guardians, and whose job is to decide the best course for society. They are thus like the charioteer using reason to control the desires of the trades-people and the energetic drive for honor among the guardians. But the greatest ruler is the philosopher-king who has knowledge of the Forms. Plato describes the role of the philosopher-king here:


Until philosophers are kings, or the kings and princes of this world have the spirit and power of philosophy, and political greatness and wisdom meet in one, and those commoner natures who pursue either to the exclusion of the other are compelled to stand aside, cities will never have rest from their evils – no, nor the human race, as I believe. Only then will our State have a possibility of life and behold the light of day. . . . We will discover some people whose natures are such that they ought to study philosophy and to be leaders in the State. There are others who are not born to be philosophers, and are meant to be followers rather than leaders. . . . And may we not say of the philosopher that he is a lover, not of a part of wisdom only, but of the whole? [Republic, Bk. 5]


             Plato stresses the importance of everyone—trades-people, guardians and rulers—sticking within their own class and performing their assigned function. This is precisely what a just society consists of and what occurs when “each does his own.” In the following Plato describes the chaos that can occur when people go outside their respective classes:


We will recognize that justice is the having and doing what is a person’s own, and belongs to him. . . . Suppose that a shoemaker, or any other man whom nature designed to be a tradesperson, has his heart lifted up by wealth or strength or the number of his followers, or any like advantage, and attempts to force his way into the class of guardians. Suppose a guardian moves into that of rulers and guardians, for which he is unfitted, and either to take the implements or the duties of the other. Suppose that one man is a tradesperson, ruler, and guardian all in one. I think you will agree with me in saying that this interchange and this meddling of one with another is the ruin of the State. [Ibid, Bk. 4]


             Clearly, according to Plato, there is a great social need for everyone to stay within their designated ranks. Suppose, though, that Bob the tradesman wants to be a guardian. What’s to stop him from following his dreams? Plato’s answer is that we need to trick people into thinking that they are naturally assigned their places in the social hierarchy, and thus should be content in their current status. One way of accomplishing this is to brainwash them with a religious myth about how the gods forged each of the three classes of people out of a different kind of metal: trades-people were made with iron and brass, guardians with silver, rulers with gold (ibid, Bk. 3). It’s of course a lie, but it’s a noble lie that brings about the needed consequence of social order. Is there any possibility people will believe this tale? Not with the first generation of people that hear the story, Plato suggests, but future generations will very likely fall in line.


Art: Imitation, Education, Censorship

Plato had mixed feelings about artistic expression in all of its Forms—including painting, sculpture, literature, music. The basis for his view is the presumption that art is an imitation of reality, and the better the imitation, the better the art. What is crucial, according to Plato, is for art to focus on the right reality, namely, the true essences of things that are in the Forms. But artists don’t always do that and, instead, they imitate the world of appearances which, we’ve seen, is itself a poor copy of the true reality of the Forms. Thus, in the worst case scenario, art risks being a bad copy of a bad copy—that is, art badly copying the world of the senses, while the world of the senses badly copies the true realities in the Forms. For example, if an artist paints a picture of a bed, he makes a copy of a particular bed in the physical world. The craftsman who makes the physical bed, though, is producing in imperfect copy of the form of bedness, as Plato describes here:


If the craftsman does not make that which really is, then he cannot make true existence, but only something that resembles real existence. If anyone were to say that the work of the maker of the bed, or of any other craftsman, has real existence, he could hardly be supposed to be speaking the truth. . . . No wonder, then, that his work too is an indistinct expression of truth. [Ibid, Bk. 10; 597a]


             Because of art’s capacity to imitate things, all art has moral effects on people, where some of it is morally uplifting when directed towards the Forms, while some of it is morally corrupting when directed towards appearances. In literature, he argues, good models of story telling are those “narrated by Homer and Hesiod, and the rest of the poets, who have ever been the great storytellers of humankind.” On the other hand, other story tellers are to be blamed for “the fault of telling a lie, and, what is more, a bad lie.” The specific flaw occurs “whenever an erroneous representation is made of the nature of gods and heroes -- as when a painter paints a portrait not having the shadow of a likeness to the original.” As Plato sketched out the details of his perfect society, he concluded that if artistic expression was to be permitted at all, it had to be seriously censored and only then could it be a useful tool for moral education. He describes this here:


The first thing will be to establish a censorship of the writers of fiction, and let the censors receive any tale of fiction which is good, and reject the bad; and we will desire mothers and nurses to tell their children the authorized ones only. Let them fashion the mind with such tales, even more fondly than they mould the body with their hands; but most of those which are now in use must be discarded. [Ibid, Bk. 2]


Even in music, censorship is needed since some scales and rhythms are better than others. Those that evoke sorrow and relaxation should be banned, while those that bring out courage will benefit soldiers in time of war. Similarly, some instruments are better than others, and he says, “the flute is worse than all the stringed instruments put together.”




The philosophy of Aristotle (384–322 BCE) focuses on the notion that things have a natural purpose that defines what they are. Aristotle was born in a small town in Northern Greece, his father being the personal physician of the king of Macedonia. When both his parents died while Aristotle was yet a boy, he was further raised by a guardian and educated as a member of the aristocracy, studying a broad range of academic subjects. At 18, he was sent to Plato’s Academy in Athens, where Plato had found him an outstanding student, calling him the “intelligence of the school.” He remained until Plato’s death twenty years later, but left the Academy because of disapproval over Plato's successor.  Along with a small group of Plato’s disciples, Aristotle relocated to a different Greek city, which was ruled by a former student of Plato’s; during his stay there Aristotle married the ruler’s daughter, who bore him a daughter of his own.  Although Aristotle chose not to follow his father’s medical career, he gained considerable knowledge of science and traveled the area studying botany and zoology. When the reigning king of Macedonia died, the succeeding king hired Aristotle to supervise the education of his son, Alexander the Great. Alexander studied under Aristotle until his father was assassinated, at which time the son became the ruler. Two years later, Aristotle returned to Athens and founded a school known as the Lyceum, conducting courses for the next twelve years. During this time Aristotle’s wife died, and he remarried and had a son. After the death of Alexander the Great, anti-Macedonian conflict broke out, and Aristotle was charged with religious impiety. Remembering a similar issue with Socrates, Aristotle left Athens for his mother’s estate, determined that Athens would not “sin twice against philosophy.” He died one year later, but his school continued for centuries afterward.

             Like Plato, Aristotle composed philosophical dialogues intended for general readers. While none of these survive intact, a considerable number of his technical treatises have been preserved, totaling about 2,000 pages in modern printed editions. These were probably based on his lectures at the Lyceum in Athens, some parts being polished, other parts being bare outlines. The range of subjects that he covers in his treatises is vast, including logic, physics, astronomy, psychology, animal science, metaphysics, ethics, politics, and rhetoric. And, for centuries afterwards, many of these works were considered to be the ultimate authority in their subject areas.


Logic: Syllogisms, Fallacies, Categories

Followers of Aristotle grouped together several of his logical works under the title Organon, Latin for “instrument”, suggesting that logic is a foundational tool for all other reasoning. We will look at three components of his logic: the syllogism, logical fallacies, and categories.

             The most outstanding component of his logical works is his system of syllogistic logic, the first systematic formulation of deductive logic which was unsurpassed until the nineteenth-century. A “syllogism” is a special kind of argument that involves logically valid relationships between different categories of things. Here is the standard example:


(1) All humans are mortal.

(2) Socrates is human.

(3) Therefore, Socrates is mortal.


In the above there are three categories of things: men, mortal beings, and Socrates. If we abbreviate these three categories with the letters H, M and S, the logical structure of the argument emerges:


(1) All H are M

(2) All S are H

(3) Therefore, all S are M


By simply reading over each line, we can see that there is a logical thread that connects each of the statements together. The first two lines are called “premises” and supply the evidence for the argument. The third line is called a “conclusion” and is what we infer from the evidence in the premises. The evidence in the above argument shows how the three categories of things relate: (1) everything in the category of H (humans) is contained in the category of M (mortal beings), and (2) everything in the category of S (Socrates) is contained in the category of H (humans). This evidence then leads to the conclusion that (3) everything in the category of S (Socrates) is contained in the category of M (mortal beings). The above argument structure has a logical force to it called validity, which most simply means that when all the premises are true the conclusion must also be true. This is just one of 14 syllogistic argument Forms within Aristotle’s system of logic that are valid.

             Another aspect of Aristotle’s logic was his analysis of bad argument forms, particularly the intentionally deceptive argument strategies that the Sophists used when teaching public speaking skills. For many Sophists, what mattered most in public speaking was persuading the audience, and it mattered little if the arguments that one used were logical tricks. Aristotle felt otherwise, and in a book titled Fallacies of the Sophists he exposes thirteen logical tricks that were part of the Sophists’ collection. He dubs these faulty arguments “logical fallacies.” Consider this example that Aristotle himself gives:


(1) What belongs to X is the property of X (e.g., what belongs to Athenians is the property of Athenians).

(2) Humans belong to the animal kingdom.

(3) Therefore, Humans are the property of the animal kingdom.


The two premises are true enough, and the conclusion—as bizarre as it is—seems to logically follow from it. What is the logical trick behind it? The fallacy in this case is that there are actually two meanings of the phrase “belongs to”. One meaning is “property” which is stated clearly enough in premise 1. But the other meaning is “member of” which is hidden. The argument, then, secretly mixes together two distinct meanings of the phrase “belongs to”. This is the fallacy of equivocation.

             The third aspect of Aristotle’s logic is his list of categories – that is, the different ways that we can categorize reality. For example, when I say “The time now is 12:00” I’m talking about the category of time. When I say “Put that rock over there” I’m talking about the category of space. According to Aristotle, there are 10 such categories, which are listed as follows and include examples that Aristotle himself gave:


* Substance: man, horse

* Quantity: four foot, five foot

* Quality: white, grammatical

* Relation: double, half, large

* Place: in the lyceum, in the market place

* Time: yesterday, last year

* Position: is lying, is sitting

* State: has shoes on, has armor on

* Action: cutting, burning

* Affection: being cut, being burned


Most statements that we make will use only a couple categories at a time, such as “The time now is 12:00.” Here, though, is an example of a sentence that incorporates all ten categories:


Joe, who is six foot tall, wears white and is double the height of his son, was in the market place yesterday, sitting with his armor on, burning a candle, which then tipped over and burned him.


The categories serve a double function. First, they reflect the structure of reality, and the different ways that the actual world is arranged. Second, they reflect the structure of the language that we use to describe the world. They are predicates that describe a subject. In the sentence “Joe is six foot tall,” the word “Joe” is the subject and “is six foot tall” is the predicate that expresses quantity. When we take together these two functions, the predicate categories that we use in language are indicators of the categories in reality. For Aristotle, since the categories express the very nature of reality, study of them is an essential job of philosophy.


Physics: Purpose, Natural Objects, Four Causes, Unmoved Mover

Aristotle did various hands-on studies of the natural world—analyzing plants, animals, celestial objects and even the weather—and much of his work was foundational in the history of science. However, he also speculated more generally about the different forces and underlying structures of nature. We will look at four such aspects of his philosophy of nature, particularly as appear in his book Physics, all of which greatly impacted on the history of philosophy and shaped much of the philosophical vocabulary that we use even today.

             Perhaps the single most important aspect of Aristotle’s philosophy of nature is the notion of purpose, also called teleology from the Greek word telos, meaning purpose. For Aristotle, every natural object and event has a built in purpose—a goal, an aim, a function—and any examination that we make of natural things needs to take that into account. For example, the purpose of a tree is to grow up tall, sprout leaves, soak up water. The purpose of a human being is to be rational. Aristotle suggests that the purpose of a thing can be set down in a genus and species definition. For example, “human being” is defined as an animal that is rational, where “animal” is the genus (the larger category), and “rational” is the species (the sub-category). Aspects of our purpose as human beings are reflected in both the “animal” and “rational” components of this definition. We are indeed animals, and thus have functions and aims that other animals have. We desire food and have feelings of fear and rage just like many animals do. However, it is our rationality that distinguishes us from other animals, and, so, this is our higher purpose.

             A second feature of his philosophy of nature is the distinction between natural and artificial objects. Natural objects are things that exist by nature, such as a tree, and have an innate tendency to change in some ways, and stay the same in others:


Of things that exist, some exist by nature, and some from other causes [that are artificial]. ‘By nature’ the animals and their parts exist, and also the plants and the simple bodies (earth, fire, air, water). For, we say that these and similar things exist “by nature”. All the things mentioned present a feature in which they differ from things which are not constituted by nature. Each of them has within itself a principle of motion and of stability (in respect of place, or of growth and decrease, or by way of alteration). [Physics, 1.4]


Artificial objects, by contrast, are human made things, such as beds and coats. Unlike natural objects, artificial ones have no innate tendency to change or stay the same; that’s something that we humans impose on the objects. Aristotle continues,


On the other hand, [artificial objects, such as] a bed and a coat and anything else of that sort, as receiving these designations (that is, in so far as they are products of art) have no innate impulse to change. But in so far as they happen to be composed of stone or of earth or of a mixture of the two, they do have such an impulse. And they have that impulse to that extent which seems to indicate that nature is a source or cause of being moved and of being at rest in that to which it belongs primarily, in virtue of itself and not in virtue of a connected attribute. [Ibid.]


If I create a simple chair from the wood of the tree, the chair may indeed naturally change as the wood deteriorates. But the chair will not on its own grow into reclining chair, or a bar stool, or a lifeguard chair. As the chair’s creator, once I establish its shape as a basic wooden chair, there is no longer any capacity within the chair to transform into a different type of chair.

             Third is Aristotle’s conception of the four causes. Daily we think of the physical world in terms of the causes that bring about change and motion. The wind caused the door to shut, the medicine caused the illness to go away, the rain caused the plants to grow. Aristotle explains that the term “cause” has different meanings, each of which rests on a different aspect of nature. So important is the notion of causality that, according to Aristotle, “people do not think they know a thing till they have grasped the ‘why’ of it.” There are, he argues, four distinct types of causes: efficient, material, formal, and final. The efficient cause is the force behind a cause. Take, for example, a sculptor who, with chisel and hammer in hand, chips away at a stone block to create a statue. The physical act of chiseling is the efficient cause. He writes of this,


[A cause can be] the primary source of the change or coming to rest. For example, the man who gave advice is a cause, the father is cause of the child, and generally what makes of what is made and what causes change of what is changed. [Physics 2.3]


Then there is the material cause, which is the physical stuff out of which a thing is made, such as the stone that makes up the statue. He explains, “That out of which a thing comes to be and which persists, is called ‘cause’” whether it’s the stone of a statue or the silver in a bowl.” The character of the material itself causes an object to have a particular quality—such as how a silver bowl would differ from a wooden or a stone bowl. Third there is the formal cause, which is the form or shape that is causally imposed on a thing, such as the shape of the statue. It is “the form or the pattern and the definition of the essence” of a thing. Using a musical example, Aristotle explains that the form of a musical octave is a numerical ratio of 2:1, and this constitutes the cause of the sound.  Finally, there is the final cause, which constitutes the purpose for which something is done; the purpose of the statue, for example, might be to honor a famous person by putting a stone image of him on public display. He explains how final causes are particularly evident when it comes to medicine, insofar as a particular drug or activity is the purposeful cause of physical health:


[Something is a cause] in the sense of end or “that for the sake of which” a thing is done. For example, health is the cause of walking about. If asked “Why is he walking about?” we say, “To be healthy”. When we say that, we think we have assigned the cause. The same is true also of all the intermediate steps which are brought about through the action of something else as means towards the end. For example, reduction of flesh, purging, drugs, or surgical instruments are means towards health. All these things are “for the sake of” the end, though they differ from one another in that some are activities and others are instruments. [Ibid]


             A fourth important aspect of Aristotle’s philosophy of nature is that of the unmoved mover: a divine being that is responsible for the motion of the sun, moon, planets, stars, and, ultimately, all motion on earth. While his conception of the cosmos is radically different from what we know to be true today, his views were influential on astronomers for the succeeding thousand or so years. Imagine the cosmos as containing 55 glass-like spheres of differing sizes, with the smaller ones nested inside of the larger ones. Connected to each of the spheres is a celestial object: the sun is attached to one sphere, each planet and comet to its own sphere, and to largest and very outer sphere all the stars are attached. The earth is at the very center of these nested spheres, and as we look up into the sky we see the heavenly bodies move. More precisely, each sphere is moving, and we see the motion of the celestial objects that are attached to it. Now comes the big question: What makes each sphere move? They can’t just spin on their own, so something must be causing the motion.

             Aristotle’s answer has three parts to it. First, each sphere has a god right next to it, and each of these 55 gods has the job of moving the sphere that is assigned to it. Second, the gods move the spheres without the gods actually moving themselves. It’s not like the gods reach out with their hands and yank the spheres into motion. Rather, they seduce their assigned sphere into moving. Take, for example, the god assigned to the outer sphere that contains all the stars. That god is a very glorious and majestic being, so much so that its assigned sphere falls in love with that god and, in a sense, the sphere does a dance of joy in expression of that love. The type of causal motion that this god imposes on the sphere is not an efficient cause, but rather a final cause:


The object of desire and the object of thought move in this way; they move without being moved. … The final cause, then, produces motion as being loved, but all other things move by being moved. … On such a principle, then, depend the heavens and the world of nature. [Metaphysics, 12.7]


The sphere moves out of sheer attraction towards the god. Thus, the god moves the sphere, without moving itself: it is an unmoved mover. The particular god on the outermost sphere is the grandest of the 55, and, as Aristotle describes here, it is eternal, without size or parts, and unchanging. 


It is clear then from what has been said that there is a substance which is eternal and unmovable and separate from sensible things. It has been shown also that this substance cannot have any magnitude, but is without parts and indivisible … But it has also been shown that it is impassive and unalterable; for all the other changes are posterior to change of place. [Metaphysics, 12.7]


The third part of the theory is how the other 54 gods get their grandeur to seduce motion in each of their assigned spheres. As the outer god is the magnificent one of the bunch, the other 54 gods get their majesty by being allied with this greatest one. A king, for example, has the highest level of majesty. A prince derives his majesty because of his relation to the king, and so too with other nobility, like dukes, earls, knights, counts, and barons. So, the grandeur of the final god transfers down through all the gods. The sphere containing the moon is the closest to the earth. Its motion causes movement in the clouds and the wind, and this, in turn, is the cause of all other motion on earth.


Metaphysics: Matter-Form, Substance-Accident, Potentiality-Actuality

The philosophical term “metaphysics” was introduced with Aristotle’s writings, particularly his book that goes by the title Metaphysics. The prefix “meta” means “above” or “beyond”, and thus it is a study that is beyond the physical. Scholars speculate that editors of Aristotle’s writings created the term to simply refer to a book of Aristotle’s that came “after” his book on physics. Regardless of its origin, the term quickly took on a special philosophical meaning as the study of reality in its most general sense. While physical science also deals with reality, it does so through experiment and sensory observation. Metaphysics, though, concerns those aspects of reality that cannot be discovered through experimentation. The aim of metaphysics, according to Aristotle, is the discovery of a thing’s essential nature, what it means for that thing to be what it is. We will look at three important metaphysical distinctions in his writings that help clarify a thing’s essential nature. They are the relations of matter-form, substance-accident, and potentiality-actuality.

             First is Aristotle’s distinction between matter and form. We’ve already seen Plato’s view of these two concepts: perfect abstract Forms exist in a higher spirit-realm of the universe, and material things down here on earth take their shape and structure by participating in abstract Forms. Aristotle rejects Plato’s theory of matter and form, and gives two particularly compelling arguments against it. First, he argues that introducing the idea of the Forms does not clarify the nature of an object, but simply confuses things by introducing more concepts. He writes,


Above all, one might discuss the question what on earth the Forms contribute to sensible things, either to those that are eternal or to those that come into being and cease to be. For they cause neither movement nor any change in them. But again they help in no way either towards the knowledge of other things . . . or towards their being. [Metaphysics 1:9]


Second, Aristotle argues that “participation” is the key notion of the Forms, but nowhere does Plato explain what participation is. He writes,


All other things cannot come from the Forms in any of the usual senses of “from”. And to say that they are patterns and the other things participate in them is to use empty words and poetical metaphors. [Ibid.]


             Thus rejecting Plato’s theory, Aristotle’s view is that all things are combinations of form and matter: there can be no matter without form, or form without matter. Using more modern philosophical terminology, Aristotle holds that there is no “prime matter” (i.e., formless matter) and no “substantial form” (i.e., nonmaterial form). Instead, for Aristotle, both matter and form are combined together making up everything that we see around us. The oak tree outside my window has the unique form of an oak tree, but at the same time it is a form that gives shape and function to the material stuff that it is made of. Artificial as well as natural objects are like this: the table in front of me is composed of material stuff that has the shape and function of a table. Even the most substance-less form that we can think of, such as the honeycomb in a beehive, still contains some matter, namely the bee’s wax. Similarly, even the most formless blob of material stuff that we can think of still has a blob-like shape and at least some function. Aristotle did in fact speculate about the existence of formless matter, but it is a speculation that he appears to have rejected. The difference of opinion between Plato and Aristotle regarding matter and form is dramatically illustrated in a famous painting called “The School of Athens” by the sixteenth-century Italian artist Raphael. In the painting Plato and Aristotle are both descending a staircase. The elder Plato is pointing up into the air, signaling that truth and reality exist in the higher realm of the Forms. The younger Aristotle is pointing to the ground, indicating that truth and reality exist down here in the physical realm where matter and form are combined. Aristotle’s view that existing things are all a combination of matter and form is called hylomorphism (Greek for “material form”).

             The second aspect of Aristotle’s metaphysics involves the distinction between substance and accident. Let’s start with a simple illustration: “John is six feet tall.” In this statement, “John” is the substance, that is, the reality that underlies all of his qualities. By contrast, “six feet tall” is the accident, that is, a quality or property that belongs to the substance. Aristotle defines substance here:


We call “substance” the simple bodies, that is, earth and fire and water and everything of the sort, and in general bodies and the things composed of them, both animals and divine beings, and the parts of these. All these are called substance because they are not predicated of a subject but everything else is predicated of them. [Metaphysics, 5.8]


A substance, then, is simply a thing to which a property attaches. He defines “accident” here:


“Accident” means that which attaches to something and can be truly asserted, but neither of necessity nor usually. For example. . . A musician might be pale; but since this does not happen of necessity nor usually, we call it an accident. There are, then, attributes and they attach to subjects, and some of them attach to these only in a particular place and at a particular time. Thus, something will be an accident whenever it attaches to a subject, but not because it was this subject, or the time this time, or the place this place. [Metaphysics, 5.30]


That is, accidents themselves may change within a particular thing, but that change does not alter the kind of thing that each substance is. John was not always six feet tall, but he was still John. So too with other accidental properties about John, such as hair color and weight. The substance-accident distinction connects directly with Aristotle’s ten categories that we examined earlier. On that list, the first category is substance, while the remaining nine categories are accidents that attach to substances.

             The substance-accident distinction is often useful in ordinary situations like appraising antiques. Suppose that I’m looking at purchasing a specific antique table as an investment. I see that it has been refinished, which diminishes its value. That is, one of its accidental properties has changed (its finish), but it’s still in substance the same antique table. Then on closer inspection I see that one of its legs has been replaced; this is an important change, but still an accidental change that doesn’t affect its substance as an antique table. But then I see that the entire top has been replaced; this is a quite serious alteration that makes the table an entirely different object. It is no longer the same substance as the table originally was, but instead is more like a replica. In a nutshell, antique appraising comes down to the question of whether a change in an object is merely accidental, or whether it affects the substance of the thing itself.

             The third aspect of his metaphysics is his distinction between potentiality and actuality. The distinction here is commonsensical: a full-grown oak tree is in actuality a full-grown oak tree, while an acorn is potentially a full-grown oak tree. Aristotle offers these examples:


We say that potentially, for instance, a statue of Hermes is in the block of wood and the half-line is in the whole, because it might be separated out, and we call even the man who is not studying a man of science, if he is capable of studying; the thing that stands in contrast to each of these exists actually. [Metaphysics 9.6]


In short, potentiality is a capacity, and actuality is the fulfillment of that capacity. The potentiality-actuality distinction is another that is useful in ordinary situations. Teachers often scold students by saying “you have so much potential, if you’d only use it!” Aristotle considers this very situation. Take, for example, the skill of playing the violin. Before any training, we are in a state of potentiality regarding the violin: we don’t know how to play it, but we have the capacity to do so. That capacity then becomes actualized in one of two ways. First, I learn how to play—although I may decide to never pick it up and play it. Second, I not only learn how to play, but I actually pick it up and play it. In recent years, Aristotle’s distinction between actuality and potentiality has played a key role in the ethical debate on abortion, specifically concerning the status of a fetus as a potential human being. We grant that actual persons have the right to life; we also grant that fetuses are potential persons. The remaining ethical question is whether the right to life attaches to potential persons as well as actual persons. That is, is there something inherently valuable about the fetus in its state of potentiality that justifies conferring on it the right to life even before it is actualized? Critics of abortion may say yes, while its defenders may say no.


Soul: Form of the Body and Three Types

Like Plato, Aristotle also offers a detailed account of the human mind, or soul as the Greeks called it. There are two key features of Aristotle’s notion of the soul: the soul’s relation to the body, and the three types of souls.

             First, according to Aristotle, the soul and body of a human or animal are so interconnected that they are inseparable. The soul itself is the principle of life in the physical body, and is the source of self-directed nutrition, growth, movement, and feelings within it. The soul gives the body its physical shape through nutrition and growth, and it gives the body its capacity to do things. The soul is the form of the body. We’ve seen earlier that, for Aristotle, form and matter cannot be separated from each other. From that perspective, the soul and body of an organism cannot exist independently of each other: a human body without a soul is dead, and it remains a “human” body in name only. Aristotle makes this point here using an analogy of an eyeball and sight:


Suppose that the eye were an animal: sight would have been its soul (for sight is the substance or essence of the eye which corresponds to the formula, the eye being merely the matter of seeing). When seeing is removed, the eye is no longer an eye, except in name. It is no more a real eye than the eye of a statue or of a painted figure. . . . As the pupil plus the power of sight constitutes the eye, so the soul plus the body constitutes the animal. From this it indubitably follows that the soul is inseparable from its body… [On the Soul, 2.1]


In this analogy, the eyeball is like the body, and sight is like the soul. When seeing is removed from the eyeball, the eyeball itself is no longer an eyeball except in name only. Granted, then, the human body is no longer a “human” body without the soul. Can the human soul continue to exist separately from the body? Again, the answer is no for the same reason: just as form cannot exist separately from matter, the human soul cannot exist separately from the human body. He writes,


The soul does not exist without a body and yet is not itself a kind of body. For it is not a body, but something which belongs to a body, and for this reason exists in a body, and in a body of such-and-such a kind. [On the Soul, 2.2]


Unlike Plato, then, Aristotle is denying the immortality of the soul and in essence maintaining the impossibility of life after death in a disembodied soul. This aspect of Aristotle’s philosophy, more than any other, put him at odds with later philosophers who believed in the immortality of the soul.

             The second aspect of Aristotle’s view of the soul is that there are three kinds of souls, depending on how complex the living organism is. They are the nutritive, appetitive, and reasoning souls. At the lowest level is the nutritive element of the soul that is responsible for self-nourishment, growth, and decay. This is a capacity of life that plants have, and thus the nutritive aspect of the soul is sometimes also called the “vegetative” function. He explains the nutritive soul here:


What has soul in it differs from what lacks it, in that the former displays life. Now the word “living” has more than one sense; if any one alone of these is found in a thing we say that thing is living. “Living” may mean thinking or perception or local movement and rest, or movement in the sense of nutrition, decay and growth. Hence we think of plants also as living, for they are observed to possess in themselves an originative power through which they increase or decrease in all spatial directions; they grow up and down, and everything that grows increases its bulk alike in both directions or indeed in all, and continues to live so long as it can absorb nutriment. [On the Soul, 2.3]


Moving up one step is the appetitive component of the soul, which is responsible for sensation and movement. Animals have this in addition to the nutritive element, and it is the appetitive component that allows them to perceive the world, have desires, and move their bodies from place to place—tasks which plants clearly cannot do. Finally, there is the rational component of the soul, which, for Aristotle, is unique to humans, although humans possess the nutritive and appetitive components too. The range of rational abilities that humans have by virtue of this soul is extensive, and involves reasoning about science, craftsmanship, and morality. As we engage in these various types of reasoning, we never reach a level of complete knowledge, and, thus our minds switch back and forth between states of potentiality and actuality. Sometimes we know things, and other times we don’t. It is only the mind of the unmoved mover that is in a state of full actuality.


Ethics: Desire-Regulating Virtues

While all of Aristotle’s views have been highly influential, his ethical theory is particularly noteworthy because of the dominant place it even now holds in contemporary ethics. His main work on the subject is Nicomachean Ethics, named after his son Nicomachus who might have edited the book from Aristotle’s lecture notes. Three important themes emerge from his theory.

             First, happiness is connected with our function as rational humans. The goal of all human action is happiness, he argues, and while this may be obvious enough, it is less obvious what exactly happiness is. If we can indeed figure out what happiness is, then “we shall be like good archers who have a mark at which to aim, we shall have a better chance of attaining what we want” (Ethics, 1.2). Philosophers commonly identify happiness with pleasure, honor or wealth, but each of these by themselves will not bring about happiness. Rather, happiness is connected with the purpose and function of human beings, as reflected in the structure of the human soul. We’ve seen that the human soul has three components, namely, the nutritional, the appetitive, and the rational; it is the latter two that are most directly connected with human happiness. The appetitive and animalistic part of us gives us desires, but it is the rational part of us that enables us to control our desires, thus preventing us from living like mere animals. Take the appetitive desire for pleasure, for example, which animals and humans both have. Animals follow their drive for pleasure, with no restrictions on their levels of indulgence. They eat whatever and whenever they can, they engage in sex based purely on their natural urges. While humans too have the same inclinations, we control our desires through our reason, and this is an important way that our behavior differs from that of the animals.

             The second part of Aristotle’s theory is that moral virtues are desire-regulating character traits. Let’s grant that our human reason keeps us from being animals by controlling our desires. The specific way that reason accomplishes this, though, is through the development of good habits. Suppose that whenever I pass by a restaurant I have a powerful urge to go inside and order the fanciest thing on the menu. My reason, though, talks me out of it by having me considering the impact that overeating would have both on my health and my budget. When this happens enough times, I’ll develop a good habit that enables me to resist that desire. That desire-regulating habit is a moral virtue, and the development of such habits is precisely what morality is all about. Since we have a wide range of desires that emerge from the appetitive part of our soul, there are an equally wide range of moral virtues that we need to develop to curb those desires.

             The third part of his theory is the doctrine of the mean. Whenever we develop desire-regulating habits that are good, they are midway between two bad ones. Take again the example of restraining myself from going to restaurants. When I properly regulate my desire for pleasurable food, that good habit is called the virtue of temperance. Suppose that I fail miserably at the task and instead develop a bad habit of indulging every time I have a craving: this bad habit is the vice of over-indulgence. On the other hand, suppose that I restrain myself too much and get into the habit of never eating anything pleasurable. That too is a bad habit and is the vice of insensibility. Thus, as I seek the perfect habit to regulate my desires, I want the middle ground between the two vices of excess and deficiency. The chart below shows the virtues and vices that pertain to five particular natural urges:


Natural Urge || Vice of Deficiency | Virtuous Mean | Vice of Excess


Pleasure           || Insensibility              Temperance                 Overindulgence

Fear of danger || Cowardice                Courage                       Rashness

Anger               || Spiritlessness            Good Temper              Ill-temper

Give money    || Stinginess                 Generosity                   Extravagance

Importance      || Timidity                    Self-Confidence          Conceit


             Aristotle warns that the virtuous mean is not a strict mathematical calculation between two extremes. For example, if eating 100 apples is too many, and eating zero apples is too little, this does not imply that we should eat 50 apples, which is the mathematical mean. Instead, the mean is rationally determined, based on the relative merits of the situation. That is, it is “as a person of good judgment would determine it.” With apples, a person of good judgment might conclude that one or two apples a day is the way to go. Aristotle concludes that it is difficult to live the virtuous life primarily because it is often difficult to find the proper mean between the extremes:


It is always hard work to find the mean in anything, for example, it is not everybody, but only a person of science, who can find the mean or center of a circle. So too anybody can get angry—that is an easy matter—and anybody can give or spend money, but to give it to the right persons, to give the right amount of it and to give it at the right time and for the right cause and in the right way, this is not what anybody can do, nor is it easy. [Ethics, 2.9]


Politics: Natural Rulers

In his book Politics, Aristotle wrote extensively on the subject of governments. While Plato’s account of politics involves an elaborate plan for the perfect society, Aristotle mainly dissected the different functions of government, in much the way that a biologist would describe and analyze the parts of an animal. One aspect of his political theory, though, connects directly with his larger view of human nature: the formation of governments is something that humans do naturally. He writes:


It is evident that the state is a creation of nature, and that people are by nature political animals . . . .  Now, it is evident that man is more of a political animal than bees or any other social animals. Nature, as we often say, does nothing in vain, and man is the only animal whom she has endowed with the gift of speech. [Politics, 1.2]


One reason for this is that people are not self-sufficient, and rely on society for their survival. Thus, society is prior to both the individual and even the family. Nature has implanted within us a social instinct, and when we follow this to perfection, we are “the best of animals, but when separated from law and justice, we are the worst of all.”

             Just as human society itself emerges as directed by nature, so too does nature assign us different roles to play in society. Some of us, he argues, are natural rulers and others are natural slaves; this is something that is both necessary and useful for society. Virtually everything in nature is split between one element that rules, and another that follows:


A distinction between the ruling and the subject element comes to light in all things which form a composite whole and which are made up of parts, whether continuous or discrete. Such a duality exists in living creatures, but not in them only. It originates in the constitution of the universe. Even in things that have no life, there is a ruling principle, as in a musical scale. [Politics, 1.5]


For Aristotle, this ruler-subject split is even seen in individual creatures insofar as an organism’s soul rules over its body. Thus, to the extent that human governments are an outgrowth of nature, we should expect to find a natural distinction among people.  Within human households, which are the smallest governing units of society, there are three main ruler-subject divisions: husband-wife, master-slave, father-child. There is, Aristotle argues, a character difference between the ruler and subjects in these categories which underlie the natural hierarchy. This does not imply that women and children are natural slaves; rather, these are separate hierarchical categories fashioned by nature for separate purposes.

             Still, this is not the most flattering component of Aristotle’s philosophy, and, in centuries to come, his idea of natural rulers and natural slaves had been regularly drawn upon to defend oppressive social policies. But return again to Raphael’s “School of Athens” in which he depicts Aristotle pointing downward towards truth. Slavery was an ever-present reality in the social realm that Aristotle was investigating, and he could ignore that fact no more than the facts of animal physiology that he studied. He thus found a spot within his system of nature for the master-slave relation. To break free of the brutal facts of the physical world that we see around us, one needs to point upward towards a higher realm of truth, as Plato does in Raphael’s painting. Not surprisingly, in his political philosophy Plato creates a blueprint for a perfect social system that radically departs from the actual social structures of his day. For example, in his account of the guarding class, we find men and women having equal status. If there is a moral to this story it is that philosophy benefits with a diversity of theories, some of which point downwards, others upwards.


Art: Imitation and Catharsis

A final area of Aristotle’s philosophy is his theory of art, which we find in his book Poetics. While the work focuses on the art of poetry—and poetic tragedies specifically—it has implications on all forms of art, including painting, sculpting and music. Like Plato, Aristotle believed that art was a type of imitation. This is clearly seen in paintings and sculpture, which capture the visual image of a person. But even with poetry and music imitation takes place. Imitation differs in the various arts in three respects: “the medium, the objects, the manner of imitation, being in each case distinct” (Poetics, 1). We can imitate people or events through the medium of colors, voice, rhythm, language, harmony, or some combination of these. Music, for example, employs both rhythm and harmony. Even dancing counts as an art that imitates things, specifically through the medium of rhythm. What exactly does dance imitate? Through rhythmical movement, Aristotle explains, it imitates character, emotion, and action.

             Also like Plato, Aristotle believed that art carries a moral message. Since art imitates people, and people are either good or bad, then art too reflects the moral qualities of people. There is flexibility within art as to how good or bad we represent people, and sometimes we can portray people much better or worse than they actually are:


The objects of imitation are men in action, and these men must be either of a higher or a lower type (for moral character mainly answers to these divisions, goodness and badness being the distinguishing marks of moral differences). It follows that we must represent men either as better than in real life, or as worse, or as they are. It is the same in painting. . . . The same distinction marks off tragedy from comedy; comedy aims at representing men as worse, tragedy as better than in actual life. [Poetics, 2]


             There’s a unique quality that some forms of art have, namely that they help purge or flush out our negative emotions. The term for this is catharsis, and, while Aristotle only gives two brief references to this function of art, it has nonetheless been influential. In one place he simply states that music has this ability to purge emotions (Politics, 8.7). In another he states that tragic poetry does this “through pity and fear effecting the proper catharsis (or purging) of these emotions” (Poetics, 6). A good example of what he’s talking about is the kind of emotional release that I might experience when seeing a horror movie or reading a dramatic novel. Throughout the day we build up negative feelings that stay within us, just festering. The best thing for us would be to release those emotions, and nothing does this better than screaming in the movie theater or having our hearts pound as we read a dramatic story. When Greek audiences attended tragic plays, they were very vocal with their reactions, groaning and crying as they viewed the downfall of the tragic hero on stage.




It’s difficult to imagine what the history of philosophy would have been like if Socrates, Plato and Aristotle had not existed – or perhaps worse yet, if their writings had all been lost to the ravages of time as happened with those of the Presocratic philosophers. Socrates set in place the ideal model for the philosopher. We should pursue truth, even at the risk of going against popular social and religious beliefs. We should critically investigate theories, scrutinize their arguments, and reject what is unsound.  And ultimately, we should admit when we don’t have the final answer to a problem. While Socrates set out the goal and style of philosophizing, Plato added to its substance. His conceptions of absolute truth, human knowledge, and the human mind became the raw materials for philosophy down through the ages. The twentieth-century philosopher A.N. Whitehead said it best: “The safest general characterization of the European philosophical tradition is that it consists of a series of footnotes to Plato.” Today few people believe in Plato’s view of the Forms, but until as recently as 200 years ago it was the leading way of articulating the notion of absolute truth. Even now it is an indispensible way of characterizing the most optimistic conception of truth, even if we don’t accept it. Aristotle added further to our basic philosophical toolkit with his views of logic, natural purpose, causality, substance, and virtue. These are all part of our current philosophical vocabulary, and, when we seek clarification on any of these notions, we start by looking at what Aristotle said on the subject. Aristotle also gave us an alternative way of conceptualizing reality: rather than looking for it in the other-worldly realm of the Forms as Plato did, Aristotle says that we find it right here in the physical things that we see around us.

             As philosophy continued to develop after Socrates, Plato and Aristotle, it always looked back to these three founding fathers as something like authority figures. While they were certainly not correct in everything that they said, they laid before us the main philosophical issues, and they gave us the instruments for continuing the dialogue.


READING 1: SOCRATES ON TRIAL (from Plato, Apology)


Older Accusers Portrayed Socrates as a Natural Philosopher and Sophist

First, I must reply to older charges and my first accusers, and then I will go on to the later ones. I have had many accusers from the past, who have falsely attacked me before you during many years. . . . their charges against me go way back, and were made by them in the days when you were more impressible than you are now, in your childhood, or maybe in your youth. But the accusation when heard was simply assumed to be true, for there was no one to answer it. . . . What do the slanderers say? They will be my prosecutors, and I will sum up their words in an affidavit: “Socrates is an evil-doer, and a prying person, who searches into things beneath the earth and in heaven; he makes the worse appear the better cause, and he teaches these doctrines to others.” Such is the nature of the accusation. It is exactly what you have yourselves seen in the comedy of Aristophanes [The Clouds]. In this he has introduced a man whom he calls Socrates, going around and saying that he walks in air, and talking a lot of nonsense about matters of which I do not pretend to know either much or little (although I do not I mean to speak critically of anyone who is a student of natural philosophy). . . . Now, there is just as little foundation for the report that I am a teacher who takes money. This accusation certainly has no more truth in it than the other. Although, if someone were really able to teach, in my opinion it would be honorable to receive money for giving instruction.


Challenging Apollo and the Oracle of Delphi: Why Socrates became Hated

I dare say, Athenians, that someone among you will reply, “Yes, Socrates, but what is the origin of these accusations which are brought against you. There must have been something strange which you have been doing? All these rumors and this talk about you would never have arisen if you had been like other men: tell us, then, what is the cause of them, for we would be sorry to judge hastily of you.” Now I regard this as a fair challenge, and I will try to explain to you the reason why I am called wise and have such an evil fame. . . . You must have known Chaerephon; he was an early friend of mine, and also a friend of yours, for he shared in the recent exile of the people, and returned with you. Well, as you know, Chaerephon was very impulsive with everything that he did. He went to Delphi and boldly asked the oracle to tell him whether—as I said, I must beg you not to interrupt—he asked the oracle to tell him whether anyone was wiser than I was. . . . After long consideration, I thought of a method of testing the question. I reflected that if I could only find a man wiser than myself, then I might go to the god with a refutation in my hand. I would say to him, “Here is a man who is wiser than I am; but you said that I was the wisest.”


Socrates Examines and Alienates Politicians, Poets and Craftsmen

So, I went to one who had the reputation of wisdom and observed him; his name I need not mention. He was a politician whom I selected for examination, and the result was this. When I began to talk with him, I could not help thinking that he was not really wise, although he was considered wise by many, and still wiser by himself. Immediately I tried to explain to him that he thought himself wise, but was not really wise. The consequence was that he hated me, and his hostility was shared by several who were present and heard me. . . . After the politicians, I went to the poets: tragic, dithyrambic, and all sorts. There, I said to myself, you will be instantly detected. Now you will find out that you are more ignorant than they are. Accordingly, I took them some of the most elaborate passages in their own writings, and asked what was the meaning of them, thinking that they would teach me something. Will you believe me? I am almost ashamed to admit the truth, but I must say that there is hardly a person present who would not have talked better about their poetry than the poets did themselves. Then I knew that it is not by wisdom do poets write poetry, but by a sort of genius and inspiration. They are like diviners or soothsayers who also say many fine things, but do not understand the meaning of them. The poets appeared to me to be much in the same case. I further observed that upon the strength of their poetry they believed themselves to be the wisest of men in other things in which they were not wise. So I left, thinking myself to be superior to them for the same reason that I was superior to the politicians.

             Finally, I went to the artisans. I was conscious that I knew nothing at all, as I may say, and I was sure that they knew many admirable things. Here I was not mistaken, for they did know many things of which I was ignorant, and in this they certainly were wiser than I was. But I observed that even the good artisans fell into the same error as the poets. Because they were good workmen they thought that they also knew all sorts of higher matters, and this defect in them overshadowed their wisdom. Therefore I asked myself on behalf of the oracle, whether I would like to be as I was, neither having their knowledge nor their ignorance, or like them in both. I answered to myself and to the oracle that I was better off as I was.


Wisdom Consists of Recognizing One’s Ignorance

This inquisition has led to my having many enemies of the worst and most dangerous kind, and has given occasion also to great slander. I am called wise, for my hearers always imagine that I myself possess the wisdom which I find wanting in others. But the truth is, men of Athens, that the god only is wise, and by his answer he intends to show that the wisdom of men is worth little or nothing. He is not speaking of Socrates, he is only using my name by way of illustration. It is as if he said, “Among you mortal men, he is the wisest, who, like Socrates, knows that his wisdom is in truth worth nothing.” So I go about the world, obedient to the god, and search and make inquiry into the wisdom of anyone, whether citizen or stranger, who appears to be wise. If he is not wise, then in vindication of the oracle I show him that he is not wise. My occupation completely absorbs me, and I have no time left either for any public matter of interest or any concern of my own. I am in utter poverty by reason of my devotion to the god.

             There is another thing. Young men of the richer classes, who have little to do, hang around me by their own choice. They like to hear the pretenders examined, and they often imitate me, and proceed to examine others. There are plenty of persons, as they quickly discover, who think that they know something, but really know little or nothing. Then, those who are examined by them are angry with me, instead of being angry with themselves. This annoying Socrates, they say. This villainous misleader of youth!  . . . This is the reason why my three accusers, Meletus and Anytus and Lycon, have come after me. Meletus has a quarrel with me on behalf of the poets, Anytus, on behalf of the craftsmen and politicians, and Lycon, on behalf of the rhetoricians.


Athens Benefits from Socrates being an Inquisitive and Nagging Gadfly

I want you to know, that if you kill someone like me, you will injure yourselves more than you will injure me. . . . For if you kill me you will not easily find a successor to me since I am a sort of gadfly (if I may use such a ridiculous figure of speech) and am given to the state by the god. The state is a great and noble horse that is slow in its motions because of its large size and needs to be agitated into life. I am that gadfly which the god has attached to the state, and all day long, and in all places, I am always latching onto you, provoking, persuading and criticizing you. You will not easily find another like me, and therefore I would advise you to spare me. . . . Someone may wonder why I go about in private giving advice, and busying myself with the concerns of others, but do not come forward in public and advise the state. . . . Do you think that I could have survived all these years, if I had led a public life, supposing that, like a good man, I had always maintained what is right and pursued justice as the most important? No indeed, men of Athens, neither I nor any other man. But I have been always the same in all my actions, public as well as private. . . .


The Unexamined Life Not Worth Living

Someone will say: “Yes, Socrates, but why can’t you hold your tongue, and then you might go to a foreign city and no one will interfere with you? Now I have great difficulty in making you understand my answer to this. For you will not believe that I am serious if I tell you that I cannot hold my tongue since doing so would be disobedient to the god. You are still less likely to believe me if I say again that daily discourse about virtue (and the other things about which you hear me examining myself and others) is the greatest human good, and that the unexamined life is not worth living. Yet I say what is true, although it is something of which it is hard for me to persuade you.




The Allegory of the Cave (from Republic, 7)

Socrates: Let me now illustrate the extent to which our nature is enlightened or unenlightened. Imagine people living in an underground cave, which has a mouth that is both open towards the light and reaches all along the cave. They have been here since their childhood, and have their legs and necks chained so that they cannot move, and can only see in front of them, being prevented by the chains from turning their heads around. Above and behind them a fire is blazing at a distance, and between the fire and the prisoners there is a raised pathway. If you look, you will see a low wall built along the pathway, like the screen that puppeteers have in front of them, over which they show the puppets.

             Glaucon: I see.

             Socrates: Do you see men passing along the wall carrying all sorts of vessels, statues and figures of animals made of wood and stone and various materials, which appear over the wall? Some of them are talking, others silent.

             Glaucon: You have described a strange image, and they are strange prisoners.

             Socrates: They are like us. They see only their own shadows, or the shadows of each other, which the fire throws on the opposite wall of the cave?

             Glaucon: True. How could they see anything but the shadows if they were never allowed to move their heads?

             Socrates: Of the objects which are being carried in a similar way would they only see the shadows?

             Glaucon: Yes.

             Socrates: If they were able to speak with each other, would they not suppose that they were naming what was actually before them?

             Glaucon: Very true.

             Socrates: Suppose further that the prison had an echo that came from the other side, would they not be sure to imagine that, when one of the passing carriers spoke, the voice which they heard came from the passing shadow?

             Glaucon: No question.

             Socrates: To them the truth would be literally nothing but the shadows of the images.

             Glaucon: That is certain.

             Socrates: Now look again, and see what will naturally happen if the prisoners are released and corrected of their error. At first, if one of them is freed, suddenly stands up, turn his neck around, walks and looks towards the light, he will feel sharp pains. The glare will distress him, and he will be unable to see the realities of which in his former state he had seen the shadows. Next imagine someone saying to him that what he saw before was an illusion, but that now, when he is approaching nearer to being and his eye is turned towards more real existence, he has a clearer vision. How will he reply? You may further imagine that someone pointing to the objects as they are carried past and requiring him to name them. Will he not be confused? Will he not imagine that the shadows which he formerly saw are truer than the objects which are now shown to him?

             Glaucon: Far truer.

             Socrates: If he is compelled to look straight at the light, will he not have a pain in his eyes which will make him turn away to take shelter in the objects of vision which he can see? Will he not conceive these to be in reality clearer than the things which are now being shown to him?

             Glaucon: True.

             Socrates: Suppose once more that he is reluctantly dragged up a steep and rocky path, and held tightly until he is pulled into the presence of the sun itself. Is he not likely to be pained and irritated? When exposed to the light, with his eyes dazzled, would he be able to see anything at all of what are now called realities?

             Glaucon: No, not at first.

             Socrates: He will need to grow accustomed to the sight of the upper world. First he will see the shadows best, next the reflections of men and other objects in the water, and then the objects themselves. Then he will gaze upon the light of the moon and the stars and the sparkling heaven. He will see the sky and the stars by night better than he will see the sun or the light of the sun by day.

             Glaucon: Certainly.

             Socrates: Finally, he will be able to see the sun, and not mere reflections of it in the water, but he will see it in its own proper place, and not in a different one. He will examine it as it is.

             Glaucon: Certainly.

             Socrates: He will then proceed to argue that it is the sun that makes the season and the years, and is the guardian of all that is in the visible world, and in a certain way the cause of all things which he and his fellows have been accustomed to see.

             Glaucon: Clearly. He would first see the sun and then reason about him.

             Socrates: When he remembered his old dwelling, and the presumed wisdom of the cave and his fellow-prisoners, do you not suppose that he would feel happy about himself because of the change, and pity them?

             Glaucon: Certainly.

             Socrates: Suppose that they were in the habit of awarding honors among themselves on those who were quickest to observe the passing shadows. They would comment about of them went before, which followed after, which were together, and who were best able to draw conclusions as to the future. Do you think that he would care for such honors and glories, or envy the possessors of them? Would he not say with Homer, “Better to be the poor servant of a poor master” and to endure anything, rather than think as they do and live after their manner?

             Glaucon: Yes. I think that he would rather endure anything than entertain these false notions and live in this miserable manner.

             Socrates: Imagine again such a person suddenly coming out of the sun to be replaced in his old situation. Would he not be certain to have his eyes filled with darkness?

             Glaucon: Absolutely.

             Socrates: Suppose that there was a contest, and he had to compete in measuring the shadows with the prisoners who had never moved out of the den. He would do this while his sight was still weak, and before his eyes had become steady (and the time which would be needed to acquire this new habit of sight might be very considerable). Would he not be ridiculous? Men would say of him that up he went with his eyes, and down he came without them. They would say that it was better not even to think of ascending. If anyone tried to free them and lead them up to the light, if they could catch the offender, they would kill him.

             Glaucon: No question.

             Socrates: This entire allegory, Glaucon, you may now connect with the previous argument. The cave is the world of sight, the light of the fire is the sun. You will not misunderstand me if you interpret the journey upwards to be the ascent of the soul into the intellectual world (based on my inadequate understanding which I presented to you at your request, whether I am correct or incorrect only the gods know). But, whether true or false, my opinion is that, in the world of knowledge, the Form of the good appears last of all, and is seen only with great effort. When seen, it is also understood to be the universal author of all things that are beautiful and right. It is the parent of light, and the parent of the lord of light [i.e., the physical sun] in this visible world. It is the immediate source of reason and truth in the intellectual realm. It is the power upon which he who would act rationally either in public or private life must have his eye fixed.

             Glaucon: I agree, as far as I am able to understand you.

             Socrates: Further, you must not wonder that those who achieve this sublime vision are unwilling to descend to human affairs. For their souls are always hurrying towards the upper world where they desire to dwell. This desire of theirs is very natural, if we may trust our allegory.

             Glaucon: Yes, very natural.

             Socrates: Is there anything surprising if someone acts in a strange manner if he passes from divine contemplation to the evil state of human existence? While his eyes are blinking and before he has become accustomed to the surrounding darkness, he may be compelled to fight in courts of law, or in other places, about the images or the shadows of images of justice. He would be trying to address the conceptions of those who have never yet seen absolute justice.

             Glaucon: Anything but surprising.




Please answer all of the following questions.


1. What were the charges against Socrates?

2. What are the three parts to the Socratic dialectical method?

3. What are Socrates’ two arguments for obedience to the state?

4. According to Plato, what is the difference between knowledge and opinion?

5. According to Plato, what are the four main features of the Forms?

6. What is Plato’s argument for the immortality of the soul from the Forms?

7. What, for Plato, are the three parts of the soul, and what do they do?

8. What, for Plato, are the three parts of society, and what is the function of each?

9. According to Aristotle, what is the difference between natural and artificial objects?

10. According to Aristotle, how are matter and form related?

11. According to Aristotle, what is the distinction between substance and accident.

12. According to Aristotle, how are soul and body related?

13. For Aristotle, what are the three kinds of souls?

14. What are moral virtues, and what is their relation to vices?

15. Why, according to Aristotle, are there natural rulers and natural subjects?

 [Reading 1: Socrates on Trial]

16. In the Apology, what is Socrates’ response to Aristophanes’ portrayal of him?

17. In the Apology, what did Socrates find wrong with the claims to knowledge by the politicians, poets and craftsmen?

18. In the Apology, Socrates states that if he is executed Athens will injure itself more than it will Socrates. What is Socrates’ rationale for this statement?

[Reading 2: Plato’s Allegory of the Cave]

19. Plato’s Allegory of the Cave, what does the prisoner experience when he is first freed?

20. At the close of Plato’s Allegory of the Cave, what does say is represented by the cave, the fire, and the journey upward?

[Short Essay]

21. Short essay: pick any one of the following views in this chapter and criticize it in a minimum of 150 words. Pick any one of the following views by Socrates, Plato, or Aristotle and criticize it in a minimum of 150 words.  Socrates: that wisdom consists of knowing that you know nothing; that we owe the state obedience as a debt of gratitude. Plato: that the universe is split between the perfect realm of the Forms and the imperfect physical world; that we gain knowledge of the Forms by recollecting them from a past-life encounter in the spirit-realm; that death releases the soul from bodily limitations; that governments can rightfully trick people into thinking that they are naturally assigned their places in the social hierarchy; that art is a bad copy of a bad copy. Aristotle: that all natural objects have a built-in purpose; that there is an unmoved prime mover of the cosmos; that the body and soul are inseparably connected as matter and form; that there are three kinds of souls, namely, nutritive, appetitive and rational; that virtues are a mean between vices of deficiency and vices of excess; that there are natural rulers and natural subjects; that drama has a cathartic effect.