From Moral Issues that Divide Us


James Fieser


Revised: 9/1/2017






Animal Sexual Behavior

Human Sexual Behavior

Homosexual Activity

What People Think

Ethical Issues

Aquinas: Natural Law

Kant: Respect for Humanity

Bentham and Paley: Utilitarian Cost-Benefit

De Sade: Unlimited Sexual Freedom

Goldman: Personal Freedom with Responsibility

Public Policy Issues



Homosexuality and Gay Marriage

Common Arguments Pro and Contra

The Conservative Position

The Liberal Position

A Middle Ground

Reading 1: Sex Only for Reproduction (from Thomas Aquinas, Summa Contra Gentiles)

Reading 2: The Right of Same-Sex Couples to Marry (from Obergefell v. Hodges, 2015)

Study Questions




Jane, a sophomore in college, was raised in a conservative family and actively attended a Baptist church. Her parents instilled within her the conviction that she should wait for marriage before having sex, and she even signed a purity pledge, promising to God to stay pure until marriage. During high school she dated a boy from her church, but she nevertheless stuck to her vows. Shortly after entering college, though, she fell in love with a handsome student named Bob, their relationship got steamy, and she set her purity vow aside. A particularly popular and social guy, Bob brought Jane to drinking parties across campus that would go on late into the night, and the two would frequently crash on a bedroom floor with other guests. On one occasion, a couple in the same room began getting intimate; Bob followed suit with Jane. The lights were off, and both couples were under covers on the opposite sides of the room, and Jane, though a little embarrassed, complied. The situation repeated itself the next night, but this time both couples were in more plain view. The two couples became close friends, and before long they swapped partners, and the guys encouraged the girls to be intimate with each other. They took digital pictures of their activities, blotting out their faces, and posted them on the internet. Jane and Bob drifted apart and she began casually dating on her own, typically sleeping with her new date on the first night. As Jane’s sexual contacts began to grow, she had to be treated for chlamydia and gonorrhea. One day while cleaning out her dresser she found her old purity pledge and laughed. What she became in college was exactly what she was hoping to avoid in high school.

            Jane’s story represents a range of sexual activities that raises moral questions: is it OK to have premarital sex, group sex, homosexual sex, casual sex, and one night stands? Is it OK to view sexually explicit photos, or post some of your own on the internet? The list continues when couples are married: is it OK to have adulterous relationships, swap spouses, or have more than one spouse? Some married couples have polyamorous relationships, that is, have more than one sexual partner at a time with the knowledge and consent of everyone. The liberal answer to all of these questions is a qualified yes: these activities are morally permissible, so long as they are done between consenting adults and no one is harmed or exploited. The traditional answer is an unqualified no: none of these activities is acceptable, and the only morally proper context for sexual activity is within a committed marriage between one man and one woman. For convenience, throughout this chapter we will use the term “non-traditional sexual practices” to refer to the above list of sexual activities, and “traditional sexual practices” to refer to the marriage-only view.




When we consider non-traditional sexual behaviors such as premarital sex, adultery, and homosexuality, we invariably make moral judgments about them, much as we do any other morally controversial issue. What is unique about the issue of sexual morality, though, is that there is an underlying biological drive towards sexual activity. We do not, by contrast, have a biological inclination to take recreational drugs, abort fetuses, damage the environment, harm animals, or engage in most other morally controversial actions. While understanding the biological factors of human sexuality will not by itself resolve the moral issues, it does reveal the kind of sexual creatures that we are by nature.


Animal Sexual Behavior

There is no mystery regarding the main biological purpose of sexual activity in both humans and animals: it is a mechanism for procreation, and the pleasure associated with it is a reward system to encourage procreation and thereby ensure the continuation of one’s genetic line and species. Biologists believe that sexual reproduction emerged within the animal world 300 million years ago, with asexual reproduction being the sole means prior to that. Animal species each have their own mating rituals, and it is impossible to clump all animal sexual behavior into a single category. However, one of the more important sexual issues regarding animals is the extent to which they are by nature monogamous, that is, inclined to have a single mate. For decades, conventional wisdom had it that many species mated for life, particularly birds, but more recent science has overturned that presumption.

            Only about 4% of mammals mate for life, such as otters, bats and beavers. But even in these cases most are not completely faithful to their partners, and DNA tests show that 10% or more of the offspring of monogamous animals are sired by different fathers. Biologists sometimes make a distinction between “social monogamy,” indicating that an animal couple consistently lives together, and “genetic monogamy,” where couples have a consistently single sexual partner. Thus, genetic monogamy in animals is even rarer than social monogamy. Monogamy in general may be a useful survival mechanism when the offspring are especially at risk and may benefit by having two parents. But socially monogamous animals that play the field also have survival advantages: females have an opportunity to pick better genes for their offspring, and philandering males increase the chance of continuing their genetic line by fathering as many children as they can. It is unlikely that animals have these reproduction benefits in mind while either remaining faithful or cheating; rather, it is more like a blind inner impulse that drives them to their respective sexual behaviors.

            The sexual behavior among primates, our closest genetic relatives, is particularly diverse. About 15% are socially monogamous, such as Gibbons apes and Marmosets monkeys. At the other extreme are Bonobo apes, sometimes called Pygmy Chimpanzees, which are notoriously promiscuous. Sex, for the Bonobo, functions as a mechanism for social bonding, apart from its reproductive purpose. It helps establish a wide network of relationships and smoothes over conflicts. Whereas we shake hands to greet each other, Bonobos have sex. Further, different males within their community copulate successively with the same adult female and, when an infant is born, each male behaves as if it is the father. Less than one-third of their sexual contacts are between adults of the opposite sex: much of it is bisexual and incestuous. Their sexual techniques are also varied as they display face-to-face genital sex, tongue kissing, oral sex, and genital rubbing.


Human Sexual Behavior

If a zoologist were to classify human sexual behavior strictly based on our actual conduct, how would we compare to other primates and the rest of the animal world? While we are not as promiscuous as Bonobo chimps, we are not as monogamous as Gibbons monkeys. Sociobiologist David Barash describes our biological predisposition towards having multiple sexual partners:


Social conservatives like to point out what they see as threats to "family values." But they do not have the slightest idea how great that real threat is, or where it comes from. Monogamy is definitely under siege, not by government, declining morals, or some vast homosexual conspiracy -- but by our own evolutionary biology. Infants have their infancy. And adults? Adultery. [“Deflating the Myth of Monogamy”]


Our best information about human sexual activity comes from surveys where researchers directly ask questions to people about their sex lives. While surveys like these have been conducted with regularity in recent decades, none are completely accurate. One reason is that people are prone to lie when asked sensitive questions about their sexual histories, in part from fear that the information will leak, and in part from a sense of embarrassment over their conduct. Here, though, are some statistics.

            As a species, we begin having sex shortly after reaching puberty, with the average in the U.S. being 16 years. 95 percent of Americans have premarital sex, and surveys show that the percentage has been this high since at least the 1950s. Worldwide, people have sex on average 106 times a year; the U.S. is near the top at 138 times, and Hong Kong near the bottom at 57. The average worldwide age for marriage is 22, with Mali having the youngest at 16.4 years, and the U.S. is near the top at 26.8 years. We have many sexual partners through our lives, and, in the US the average is around 13. Men report having perhaps twice as many sexual partners as women do, and, technically speaking, this disparity is puzzling since in a closed group of heterosexual men and women, the numbers would have to be identical. Much of the difference can be explained by the fact that prostitutes are typically not surveyed in such studies, whose clients range in number from hundreds to thousands. In addition to having many sexual partners, our choices are often impulsive: almost half of U.S. adults admit to having a one night stand. Also, adultery is commonplace. A famous study by Alfred Kinsey in 1953 indicated that 50 percent of married men and 26 percent of married women had adulterous relationships by age 40. More recent studies give similar percentages and DNA tests show that as many as 10 percent of the children of socially monogamous parents are sired by a different father. 5 to 15 percent of married couples have open marriages where the partners agree that each is free to engage in extramarital relationships. Married or unmarried, use of pornography within all age groups is high, with some studies indicating regular use as high as 50%. As with most animals, then, there seems to be a biological predisposition among humans to play the field at least to some extent.


Homosexual Activity

Another fundamental sexual issue connected with human biology is homosexual orientation, that is, the predisposition to be romantically and sexually attracted to people of the same gender. As with other matters of sexual behavior, it is difficult to get a precise estimate of the number of homosexual people, and estimates range between 2 and 7 percent of the population. A critical question is whether homosexual orientation is caused by biological mechanisms or mere social conditioning, or both. There appears to be two distinct biological factors related to homosexuality, the first is genetics. Genetic experiments with fruit flies have identified a group of genes that trigger homosexual courtship and mating. The search for similar genes in humans is still ongoing, but patterns of homosexual orientation within family trees, particularly on the mother’s side, suggest that there are genetic switches involved. The second biological factor is not strictly genetic, but rather epigenetic involving chromosomal changes during fetal development where the mother’s physiology feminizes the brains of her male fetuses. The chances of this happening increases with the number of older brothers that one has. With no older brothers, the chances are 3 percent that a male will be gay; with one brother it rises to 4 percent, with two brothers 5 percent, and three or more 6 percent. These percentages hold even when brothers are not raised together. The likely biological explanation for this is that with each new male child, mothers develop an increased immunization to an antigen produced by the male fetuses, and this affects how the subsequent male fetuses develop.

            The biological basis of homosexual orientation is a principal reason for the position that sexual orientation is an ingrained characteristic of one’s sexual identity, and not a matter of choice. According to the American Psychological Association (APA),


human beings cannot choose to be either gay or straight. For most people, sexual orientation emerges in early adolescence without any prior sexual experience. Although we can choose whether to act on our feelings, psychologists do not consider sexual orientation to be a conscious choice that can be voluntarily changed. []


For that reason, the APA urges “all mental health professionals to help dispel the stigma of mental illness that some people still associate with homosexual orientation” (ibid).

            The APA also opposes what are called “conversion therapies” that seek to change the sexual orientation of homosexuals and bisexuals. A common technique in these camps is aversion therapy whereby homosexual images or thoughts are associated with an unpleasant stimuli. One participant describes a particularly brutal conversion therapy summer camp that his parents forced him to attend for three months when in high school. His hands were bound each night before going to bed to keep him from touching himself, and, when awakened between 1 and 4 a.m. each morning he would recite this prayer 1,000 times: “My parents will love me again, and I will be worthy of them and the love of Him, Christ our Lord and Savior, Through whom, I will lay down my wicked ways of faggotry and sodomy.” He was forced to take ice baths and perform repetitive acts throughout the day, such as counting the grains of salt in a salt shaker, to emphasize how much worse his sinful behavior was by comparison. Once a week, while reciting his prayer, he would be shown homosexual pornography and, if he displayed a physiological reaction, he would receive 50 lashes on his buttocks. This therapy technique was almost certainly illegal, but even less barbaric ones, according to the APA, are ineffective and even psychologically harmful to those going through the process. With the above participant, the camp did not “cure” him, but left him feeling so wicked because of his inclinations that he tried to kill himself. Ultimately his father threw him out of the house. LGBT youth are more four times more likely to seriously attempt suicide than their non-LGBT counterparts (Center for Disease Control), and as many as 40% of homeless youth identify themselves as LGBT (Williams Institute).


What People Think

Surveys about people’s moral attitudes towards sex are mixed. The majority approves of divorce and premarital sex, are equally divided about homosexuality, and disapprove of polygamy and adultery. (Gallup, 5/7-10/09)


"Next, I'm going to read you a list of issues. Regardless of whether or not you think it should be legal, for each one, please tell me whether you personally believe that in general it is morally acceptable or morally wrong.


Morally Acceptable: 62

Morally Wrong: 30

"Sex between an unmarried man and woman"

Morally Acceptable: 57

Morally Wrong: 40

"Gay or Lesbian relations"

Morally Acceptable: 49

Morally Wrong: 47

"Polygamy, when one husband has more than one wife at the same time"

Morally Acceptable: 7

Morally Wrong: 91

"Married men and women having an affair"

Morally Acceptable: 6

Morally Wrong: 92




The above information on the biology and psychology of human sexual activity describes how humans are inclined to behave sexually, but, by itself, it does not settle the issue of which sexual behaviors are morally right and wrong. Philosophers have devoted considerable time to devising arguments either for or against the moral permissibility of specific sexual behaviors, and we will consider five influential views here.


Aquinas: Natural Law

Natural law theory is the most important philosophical defense of traditional sexual practices. Its basic position is that the natural purpose of sex is reproduction, and non-traditional sexual activity is morally wrong since it conflicts with that aim. According to medieval philosopher Thomas Aquinas (1225-1274), the theory’s main proponent, God implanted within human nature a set of instincts that define our purpose as human beings and establish what is morally right. We have, for example, a divinely-implanted instinct to be sociable, and this tells us that unsociable actions are wrong, such as murder and theft. We also have an instinct to care for our young, and this tells us that we are to nurture and educate our children. Similarly, we have an instinct to procreate, which tells us that we are to have sexual intercourse for the purpose of having children. For Aquinas, this rules out adultery, fornication, and homosexuality, each of which involves sexual relations that are not for purposes of reproduction. Such sexual misconduct, according to Aquinas, is a serious sin, second only to murder since, while murder destroys life, sexual misconduct thwarts the creation of life.

            Aquinas offers a very specific argument for his procreation-only view of sex, based on the natural purpose of body parts. The various parts of our bodies have precise aims, he argues, and sex organs have the clear function of facilitating reproduction through sexual intercourse:


The members of the body being the instruments of the soul, the end of every member is the use of it, as in the case of any other instrument. But there are members of the body the use of which is for the intercourse of the sexes: that therefore is their end. [Summa Contra Gentiles 3.126]


To use our sex organs for purposes other than reproduction, then, is a misuse of that part of our body. So too with the natural purpose of semen: it is there for reproduction, and any emission of it without that purpose in mind is a sin against nature:


Hence it is clear that every emission of the semen is contrary to the good of man, which takes place in a way whereby generation is impossible; and if this is done on purpose, it must be a sin. I mean a way in which generation is impossible in itself as is the case in every emission of the semen without the natural union of male and female: wherefore such sins are called 'sins against nature.' [Ibid, 3.122]


Not only must human sexual activity aim at procreation, but, according to Aquinas, it must also be done within the context of a monogamous marriage. Men have a natural desire to be sure that their children really are theirs, which would not be possible if couples were uncommitted. Also, polygamous marriages are wrong since “one male could not provide for several females as a helper in the rearing of their progeny” (ibid, 3.124).

            A common criticism of Aquinas’s position is that we regularly use parts of our bodies for purposes other than their naturally-intended function. We use our ears to hold up our glasses, which have nothing to do with their purpose of hearing sounds. We use our teeth for chewing gum, which does not facilitate food consumption. We do not consider any of these activities immoral, so why is it immoral if we use our sex organs for purposes other than procreation? Aquinas considered this objection and has a response:


“[One might ask whether it is a sin if] one were to walk on his hands, or do with his feet something that ought to be done with his hands. The answer is that by such irregular applications as those mentioned the good of man is not greatly injured: but the irregular emission of the semen is repugnant to the good of nature, which is the conservation of the species. [Ibid, 3.122]


Aquinas suggests here that the ultimate test for whether an unnatural use of a body part is immoral is whether it is contrary to human wellbeing. Using our ears to hold up glasses is not at odds with human wellbeing, and neither is using our teeth to chew gum. But, unnatural use of our sex organs and semen hinders the preservation of our species, and thus is contrary to our welfare.

            Another common criticism of Aquinas’s position is that his procreation-only view of sex rules out any number of sexual activities that even committed married couples might practice, such as oral sex, masturbation, sex with contraception use, sex when couples are infertile, and sex after menopause. Aquinas did recognize that infertility and menopause were special situations, and sex in these cases would still be permissible:


If it is by accident that generation cannot follow from the emission of the semen, the act is not against nature on that account, nor is it sinful; the case of the woman being barren would be a case in point. [3.122]


Sex with infertile couples, he argues, is permissible since procreation is obstructed by a glitch in the reproductive system that would under normal circumstances result in pregnancy. But this provision still leaves out acts like oral sex, masturbation, and sex with contraception use. On these issues Aquinas does not budge, and neither does the Catholic Church which follows Aquinas’s natural law philosophy. But less rigid natural law theorists offer some flexibility. Rather than restricting sex to reproduction only, they see that it also serves a natural purpose of strengthening a married couple’s relationship. This would allow for a wider menu of sexual activities that would include the above three. But, the problem with this broader natural purpose of sexual activity is that it opens the door to at least some non-traditional sexual practices. Sex can also strengthen the bonds of committed couples who are unmarried, and even committed homosexual couples. Thus, to avoid going down a slippery slope of sexual permissiveness, traditional natural law theorists limit sexual activity to purposes of procreation, and that’s that.


Kant: Respect for Humanity

German philosopher Immanuel Kant (1724-1804) is another strong defender of the traditional marriage-only view of sex. The basis of his general conception of morality is that actions are wrong when we treat people disrespectfully as mere things. Instead, we should act towards others in a way that shows respect for their humanity. When I steal from you I treat you as a thing, with complete disregard for your value as a human. So too if I lie to you, assault you, or use you in any other way merely for my personal gratification. This moral formula, which he calls the categorical imperative, similarly applies to questions about sexual behavior: sexual conduct that degrades a person’s humanity is wrong. He writes, “because sexual desire is not an inclination that a person has for another as a human, but an inclination for another’s sex, this inclination is a principle of degradation of humanity” (Lectures on Ethics). For Kant, this applies to any sexual activity outside of traditional marriage. Suppose, for example, that you have an adulterous relationship. By doing so, you disrespect your spouse by diverting your time and affection towards someone else. You also show disrespect to your lover by giving him or her false hope for a long-term relationship. More importantly, you display disrespect toward yourself by treating your body as an instrument for personal gratification outside the context of the marriage union that is founded on true love. So too with premarital sex since you would be using yourself and your lover as a mere instrument for personal gratification.

            Kant argues there is something unique about the marriage relationship since it involves a commitment to one’s spouse as a whole person, not just as a sexual thing. Some sexual objectification still takes place between married couples during sex: the spouses are enjoying the other’s body, much as unmarried lovers do. What is different about marriage, though, is that spouses are devoted to the entire person of their mate, not just to their physical component. He writes, “If a person devotes to another, he is dedicated to her not only sexually, but to her whole person, and these cannot be separated” (Lectures on Ethics). Any use of sexual inclinations except within marriage, he argues, is an abuse of humanity. It is using one’s lover as merely a physical thing. Adultery and premarital sex are thus immoral. But, according to Kant, other non-traditional sex acts are so bad that they constitute crimes against nature, and those he specifically lists are masturbation, homosexuality, and bestiality. They not only strip away one’s humanity, but they lower the offender beneath the level of animals since even animals would not engage in these. They are the “most reprehensible violation that a person can commit with respect to duties to oneself,” worse even than committing suicide.

            What should we think about Kant’s uncompromising conclusions concerning the immorality of sex acts outside of marriage? Within the eighteenth-century German social structure, he may have been right that it would be degrading to oneself and one’s partner. Promiscuous women could be shunned from society, jailed, or driven into prostitution. You could not honestly say that you respect your girlfriend’s humanity while putting her at this kind of risk. But from today’s perspective it is less obvious that we of necessity treat our lover or ourselves disrespectfully as mere things when having sex outside of marriage. Many social taboos regarding sex have been lifted, and we do not risk branding ourselves or our lovers as social outcasts or criminals. Society is much more accepting of sexually active couples, particularly when they are committed to each other or live together. Since Kant’s day, opportunities for respect and devotion between unmarried lovers have increased. Further, marriage today is not what it used to be in Kant’s day. Divorce is easier, wives have their own careers, and children spend much of their time in day care or public school. Married couples have more of an opportunity to lead their own lives, even when they remain sexually faithful to each other. It may be an exaggeration to speak of marriage today as a dedication to the “whole person” of one’s spouse. The lines between the married and unmarried have thus become blurrier. While it may be morally wrong to treat people as mere things, as Kant argues, it is not obvious that this occurs with all unmarried lovers.


Bentham and Paley: Utilitarian Cost-Benefit

The utilitarian moral theory offers an approach to sexual morality that is distinct from both Aquinas’s natural law theory and Kant’s view of respect for persons. According to utilitarianism, an action is morally right if it results in more beneficial consequences than harmful ones for everyone affected. For example, to determine whether a non-traditional sexual practice like casual sex is morally wrong, we need to consider all the negative consequences of that conduct. There is the possibility of unwanted pregnancy, hurt feelings, jealousy, sexually transmitted diseases, and, if couples are married, there’s the possibility of divorce and child custody battles. The more these harmful factors are relevant to your situation, the more the conduct becomes wrong.

            British philosopher Jeremy Bentham was a founder of classic utilitarianism and he applied the utilitarian cost-benefit analysis directly to issues of sexual morality. Until recently, few respectable philosophers wrote in defense of non-traditional sexual practices, and when they did the public backlash was swift and decisive. Jeremy Bentham well understood these constraints, and what he wrote in defense of non-traditional sexual values remained in unpublished manuscript form during his life time. His overall view of sexual morality is mixed. On the one hand he argues that marriage is unquestionably justified by its beneficial consequences:


“From whatever point of view we regard the institution of marriage, we cannot fail to be struck by the utility of that excellent arrangement; the bond that holds society together; the very groundwork of our civilization. . . . . To realize its benefits to the full, we need only picture the world as it would be without the institution.” [Theory of Legislation, 1802, Ch. 19.]


On the other hand, though, he argued society would benefit from more tolerant laws regarding non-traditional sexual practices. Homosexuality should be decriminalized, and there should be reduced penalties for adultery. He also defended cohabitation and short-term marriage as alternatives to traditional marriage contracts. He writes, “Permanent connections are suitable to some situations in life: transient, to others” (quoted in Mary Sokol, “Jeremy Bentham on Love and Marriage,” The Journal of Legal History, 2009, Vol. 30).

            But, while Bentham himself saw the utility of more permissive attitudes about non-traditional sexual behaviors, other utilitarians in Bentham’s time had a more conservative cost-benefit analysis. A case in point is British philosopher William Paley (1743-1805) who gave detailed lists of harmful consequences of premarital sex, seduction, adultery, polygamy, and divorce. For example, premarital sex “discourages marriage, by abating the chief temptation to it”. It also contributes to prostitution, “produces habits of ungovernable lewdness”, and spreads venereal diseases that linger for generations. He recognized that the individual offender may not experience the full range of negative consequences from his own behavior, but he argued that the damage of premarital sex needs to be estimated by “the general tendency and consequence of crimes of the same nature”. We should thus consider what the larger consequence would be if premarital sex became universal (Principles of Moral and Political Philosophy, 1785, 3.3.2).

            The problem is that utilitarian approaches to moral decision making do not necessarily side with either traditional or nontraditional sexual practices. Rather, they only give us a formula for answering moral questions once we plug in the relevant data. The data itself are complex, and the harm that might result from premarital sex may change dramatically in different cultures depending on prevailing attitudes about marriage and single parenthood, or the availability of contraception. Social attitudes about sexual conduct vary greatly from one society to another, perhaps more than with any other morally relevant human behavior. In some societies, even today, adulterers and homosexuals can be executed for their moral crimes, whereas in other societies these practices are socially accepted. Consequentialism is an excellent method for determining whether non-traditional sexual conduct will have negative repercussions within a particular society, and whether it is wise to engage in that activity. However, that may not necessarily determine the issue of whether it is the morally right thing to do. It may say more about the rigidness or permissibility of your society than it does about the underlying moral status of that non-traditional sexual practice.


De Sade: Unlimited Sexual Freedom

Bentham’s endorsement of non-traditional sexual practices was comparatively moderate. But French author Marquis de Sade (1740-1814) takes a dramatically more radical position, arguing that nature grants us the widest possible range of sexual freedom, which justifies premarital sex, adultery, homosexuality, and prostitution. Men and women alike, he argues, are naturally designed to sleep around with everyone, and it is only unjust social conventions that force us into monogamous marriages:


It is certain that, in the state of nature, women are born vulguivaguous, that is . . . belonging to all males. Without a doubt, such were the first laws of nature and the only institutions of the first communities which men made. Private-interest, selfishness and love degraded these views, which were at first so simple and natural. One believed to grow rich by taking a woman, and with it the good of her family. [Philosophy in the Bedroom (1795)]


This, he believes, entitles anyone, male or female, to have sex-on-demand with anyone we desire, and any one sexual partner is as good as another, irrespective of age, gender, and even species. De Sade’s position on sex is grounded in an unusual version of natural law theory. For De Sade, natural instincts determine the personal pleasures in which we may rightfully indulge. Sexual inclinations are primarily there to give us pleasure, and nature does not care how we act out on that instinct, as long as we enjoy it. He writes, “Nature places no great importance on fluid which runs through our loins, and is not concerned if we prefer to direct it down one path or another.”

            There are two main problems with De Sade’s view. First, his version of natural law theory would justify my acting out on any natural instinct that gives me pleasure, including the impulse to steal or kill. De Sade himself argues just that point: “it is impossible for murder to ever be an outrage against nature” (ibid). It should not be punished by the government, he argues, and we should impose no penalty upon the murder beyond the risk he takes of vengeance of the family or friends of his victim. De Sade is essentially denying the validity of any moral code that restricts one’s behavior, a position usually called moral nihilism. If you are a moral nihilist, then De Sade is your man. But, for the clear majority of humans who embrace the basic concept of morality, De Sade’s nihilism cannot be taken seriously in a debate about sexual morality or any other moral issue for that matter.

            A second problem with his theory is that his view of sexual appetites is more descriptive of Bonobo chimps than humans. De Sade himself may have had a Bonobo-like sex drive, but he is hardly representative of the human norm. He argues that society has suppressed the unquenchable sexual appetites of both men and women, and traditional sexual practices do not reflect our true sexual nature. But that explanation is not convincing. While society and its laws do have the power to restrain our behavior, such social forces cannot redefine who we are. Cultures of all types and sizes invariably weave together the values of sex, love, marriage and family responsibility. That seems to be a better general indicator of our inclinations, and not the Bonobo-like aberrations that people like De Sade exhibit.


Goldman: Personal Freedom with Responsibility

One final theory in support of non-traditional sexual activities emphasizes the connection between personal freedom and responsibility. The idea of personal freedom arises out of the theory of natural rights, which maintains that all people are born with a set of rights, including the liberty rights to think, speak and act as we so choose. On this view, the major restriction on my conduct is whether my actions cause harm to another person. As Supreme Court Justice Oliver Wendell Holmes once said, “The right to swing my fist ends where the other man's nose begins.” Applying this principle of personal freedom to sex, then, all sexual activities are morally permissible as a matter of liberty, as long as one’s conduct does not harm someone else. This would be particularly so with sexual relations between consenting adults within the privacy of their own home, and this freedom would include the full range of non-traditional sexual behaviors. Our sexual choices, then, are on a moral par with other activities that we do with other willing partners, such as playing cards or tennis.

            A leading advocate of this view is Alan Goldman in his influential essay “Plain Sex” (1977). According to Goldman, defenders of traditional sexual practices err by viewing sex as principally a mechanism for attaining a further goal, such as reproduction or love. He calls this the means-end view and describes it here:


[Means-ends views of sex] attribute a necessary external goal or purpose to sexual activity, whether it be reproduction, the expression of love, simple communication, or interpersonal awareness. They analyze sexual activity as a means to one of these ends, implying that sexual desire is a desire to reproduce, to love or be loved, or to communicate with others. All definitions of this type suggest false views of the relation of sex to perversion and morality by implying that sex which does not fit one of these models or fulfill one of these functions is in some way deviant or incomplete. [“Plain Sex”]


Aquinas, for example, holds the means-end view by seeing the sole purpose of sex as a means of attaining the end of reproduction, and, consequently, all sexual activities are thereby immoral when they do not facilitate reproduction. Goldman rejects the means-end view of sex on the grounds that pleasures are often ends in themselves, irrespective of biological functions that they perform. “The pleasures of eating and exercising are to a large extent independent of their roles in nourishment or health (as the junk-food industry discovered with a vengeance).” Pleasures from food, exercise and sex all take on lives of their own, apart from their survival functions. Sexual desire, according to Goldman, is not a means to an end, but is simply the “desire for contact with another person's body and for the pleasure which such contact produces.”

            Unlike De Sade who believes there are no moral limits to sexual activity, Goldman argues that there are clear restrictions: we cannot harm, deceive or manipulate other people while pursuing our sexual interests. These restrictions are not unique to sexual activity but apply to all of our interactions with other people. I cannot, for example, force you to play tennis with me against your will, or club you with my tennis racket if you play better than I do. For Goldman, the connection between sex and morality is the same as it is with sports and morality. He makes this point here comparing sexual ethics with business ethics:


We can speak of asexual ethic as we can speak of a business ethic, without implying that business in itself is either moral or immoral or that special rules are required to judge business practices which are not derived from rules that apply elsewhere as well. Sex is not in itself amoral category, although like business it invariably places us into relations with others in which moral rules apply. It gives us opportunity to do what is otherwise recognized as wrong, to harm others, deceive them or manipulate them against their wills. [ibid]


Thus, sexual activities—traditional or non-traditional—have no special moral status in and of themselves, but, like any other human activity, can become tools for immoral conduct if we harm others in the process.

            Goldman’s approach to sexual freedom has a very modern feel, but his theory is by no means new. Eight centuries ago Aquinas considered a scenario similar to this: if a single woman voluntarily consents to sex and no one is harmed, is it morally permissible? Aquinas answered no: it would still be immoral since it would be contrary to our ultimate human good. Harm is certainly an important indicator of immorality, but it is not the only moral litmus test that we have. This is where Goldman may have gone wrong. The history of ethics is abundant with alternatives for testing the morality of any action, including non-traditional sexual practices. With Aquinas I may ask if I am obstructing the natural purpose of humans as responsible procreators? With Kant, am I treating myself or my lover disrespectfully as a mere thing? With Bentham, am I contributing to a way of life that undermines the greater social good? With other philosophers, am I acting contrary to a traditional value system to which I adhere? Am I developing bad habits or vices that will encumber me in the future? Not all of these moral litmus tests may be relevant to my situation, but it is hasty to dismiss them off hand and consult only the test of harm.




While in about a half dozen countries today homosexuality and adultery are punishable by death, the trend has been to decriminalize non-traditional sexual practices, and this is also the case in the U.S. The U.S. federal government has enacted several general sex laws regarding the distribution of obscene material, sex abuse, and sexual exploitation of children. But the laws pertaining to typical non-traditional sexual practices are determined by each state individually, not the federal government. Throughout U.S. history, most states have used their authority to criminalize adultery, premarital sex, homosexuality, pornography and prostitution. The result has been an inconsistent patchwork of laws from one state to another. The age of sexual consent can be 16, 17 or 18, depending on one’s state. Two states allow for some forms of prostitution, about a dozen criminalize premarital sex, and about 20 criminalize adultery. Supreme Court rulings, though, set some guidelines for the sex laws that states can or cannot enact.



For over 100 years contraception has been a major issue in public policy. The story begins in 1873 with the passage of a Federal law called the Comstock Act which banned the distribution of “obscene, lewd, or lascivious” material through the mail. This included devices or printed material aimed at “the prevention of conception.” Penalties for violating the law ranged from a $100 fine to ten years imprisonment at hard labor. Shortly thereafter, 24 states enacted similar laws against contraception. The designer of the original Federal law was Anthony Comstock, founder of an anti-obscenity organization called the New York Society for the Suppression of Vice, which assisted law enforcement agencies in several thousand obscenity convictions. Discussions about contraception at that time were as heated as abortion debates are today, and they drew on similar arguments. Comstock himself believed that birth control promoted lust and prostitution, and that contraceptives were a type of pornographic object. Other critics of contraception argued that its use is essentially murder:


As birth control means the deliberate frustration of a natural act which might have issued in a new life, it is an unnatural crime, and is stigmatized by theologians as a sin akin to murder. . . . [N]o ordinary decent man or woman approaches or begins the practice of artificial birth control without experiencing at first unpleasant feelings of uneasiness, hesitation, repugnance, shame, and remorse. [Halliday Sutherland, Birth Control (1922)]


            The Comstock Act was first challenged in 1916 when contraception activist Margaret Sanger was arrested for opening America’s first birth control clinic. On appeal, the court concluded that physicians could distribute information on contraception to married women for “the cure and prevention of disease,” but ordinary citizens like Sanger could not. Twenty years later Sanger was again in court after the U.S. government seized a shipment of contraceptive diaphragms that she ordered from Japan. By this time contraceptives were widely distributed throughout the U.S., though still prohibited by the Comstock Act. The Court ruled that the importation of contraceptives was legal for medical purposes (U.S. v. One Package, 1936).

            Still, the Comstock Act remained valid, along with similar State laws that banned contraception. Once such law was a Connecticut statute that made it a crime to use any drug or device to prevent conception. In 1961, two directors of Planned Parenthood were arrested and convicted in Connecticut after giving contraception information to a married couple. The case made its way to the Supreme Court, which overturned the conviction. Embedded in the Constitution, the Court argued, is a right to privacy that grants married couples the freedom to use contraception. To that extent, the government needs to stay out of the marriage bedroom: “Would we allow the police to search the sacred precincts of marital bedrooms for telltale signs of the use of contraceptives? The very idea is repulsive to the notions of privacy surrounding the marriage relationship” (Griswold v. Connecticut, 1965). In 1971 Congress finally rewrote the Comstock Act to remove mention of birth control, and a Supreme Court case the following year extended the right to use birth control to unmarried couples (Eisenstadt v. Baird, 1972).

            The century-long battle over contraception is by no means over, and the battleground now is sex education classes in public middle schools and high schools. One option for such classes is comprehensive sex education, which includes information about contraception. The other is abstinence-only-until-marriage education, which emphasizes abstinence as the only effective way of preventing pregnancy and sexually transmitted disease; at the same time, it stresses the inadequacies of contraceptive methods such as condoms and birth control pills. Since 1982 the U.S. Federal government has funded abstinence-only programs in public schools. Defenders of this approach appreciate the moral lesson that sex should be delayed until marriage. Any favorable discussion of contraception in sex education classes, they argue, would send a mixed message to young and impressionable students. Critics, though, argue that abstinence-only programs are ineffective, convey scientifically false or misleading information, and puts students at risk when they do become sexually active. They also use tactics of fear and shame, such as is depicted in the following account of an abstinence-only presentation:


[The abstinence-only teacher] pulled an often squirming and reluctant and always female volunteer onto the stage, took out a toothbrush that looked like it had been used to scrub toilets and asked if she would brush her teeth with it. When she predictably refused, he pulled out another toothbrush, this one pristine in its original box, and asked her if she would brush her teeth with that one. When she answered in the affirmative, he turned to the assembly and said, “If you have sex before marriage, you are the dirty toothbrush.” [Shelby Knox, U.S. House Committee hearing, Assessing the Evidence of Domestic Abstinence-Only Programs (2008)]


For other critics of these programs, it is not so much the emphasis on abstinence that concerns them, but the exclusion or denigration of contraception alternatives. They recommend middle-ground position called “abstinence-plus”: emphasize abstinence, but also include basic information on contraception.



Pornography is usually defined as the explicit depiction of sexual subject matter with the primary purpose of causing sexual arousal. A key component of pornography is that it is a representation of sexual activities through some type of media, such as drawings, photographs, film, and writing. While artistic depictions of erotic images have been around since ancient civilization, pornography as a phenomenon did not emerge until cheap and easily accessible forms of media were created. With the printing press came erotic novels, with the camera came erotic photographs, and with film came erotic movies. At each juncture these works were censored by governments and religious authorities, and in 1857 Britain enacted one of the first anti-pornography laws, the Obscene Publications Act. A few years later the Act was clarified: material is defined as obscene depending on “whether the tendency of the matter charged as obscenity is to deprave and corrupt those whose minds are open to such immoral influences and into whose hands a publication of this sort may fall.”

            In the U.S., the Comstock Act banned the distribution of obscene material through the mail, as it did with contraception. Two Supreme Court decisions placed restrictions on how far governments can go in banning pornography. In Stanley v. Georgia (1969), the Supreme Court maintained that a person can possess and view pornography: a person has “the right to satisfy his intellectual and emotional needs in the privacy of his own home.” Governments have no business controlling peoples’ private thoughts: “Our whole constitutional heritage rebels at the thought of giving government the power to control men's minds.” This, though, does not apply to the private possession of child pornography, which is specifically prohibited under both federal and state laws. While the personal possession of pornography is Constitutionally protected as a matter of liberty, the distribution of pornography is another matter, and the question is whether it is Constitutionally protected as a type of freedom of the press. In Miller v. California (1973) the Supreme Court said that it is not. States can rightfully prohibit the sale and distribution of obscene material when it meets three specific guidelines:


The basic guidelines for the trier of fact must be: (a) whether 'the average person, applying contemporary community standards' would find that the work, taken as a whole, appeals to the prurient interest . . . (b) whether the work depicts or describes, in a patently offensive way, sexual conduct specifically defined by the applicable state law; and (c) whether the work, taken as a whole, lacks serious literary, artistic, political, or scientific value. [Miller v. California]


Commonly referred to as the three-pronged Miller test for obscenity, the essence of the guidelines is this. First, the material in question must appeal to base sexual interest as judged by local community standards. There is no uniform national standard for what counts as obscene, and local communities may decide this themselves. Second, the state must have specific laws that classify the material as patently offensive, such as a designation like this: “patently offensive representations or descriptions of ultimate sexual acts, normal or perverted, actual or simulated.” Third, the material must lack serious literary, artistic, political, or scientific value. Works that have such value would be Constitutionally protected, such as a science text book that contains pictures of nude people, and thus could not be outlawed as obscene. While the Miller test for obscenity does not use the word “pornography”, it in essence draws a distinction between hardcore and softcore pornography: hardcore pornography fulfills the above three conditions and is not Constitutionally protected, while softcore pornography does not fulfill the three conditions and is thus Constitutionally protected.

            The pornography market expanded dramatically with the advent of the internet, and with that came an increase in harms from pornography through divorce, job loss because of pornography addiction, and children having easy access hardcore pornography. With this increase in social harm from pornography, should governments combat this by creating additional laws against pornography distribution? The legal answer is no. Government restrictions on pornography must follow the three-pronged Miller test for obscenity, regardless of the social harm that pornography causes. Legal scholar Rodney A. Smolla explains why:


there is a tremendous temptation for us to move against offensive speech of all kind . . . [such as] sexually explicit speech. The whole history of this country is wrapped up in the natural tendency that all of us have to know evil speech and to want to legislate against it. And the reason we have these very specific doctrines with these very demanding standards like Miller, is to prevent us from yielding to that temptation. . . . [U.S. Senate Committee hearing on Why the Government Should Care about Pornography (2005)]


However, Smolla argues, most of the pornography circulating on the internet today is hardcore and could easily pass the Miller test. It is just a question of whether governments choose to devote limited resources to the prosecution of pornography distributors. The reality is that child pornography cases monopolize prosecutors’ time and budget, which leaves few government resources for pursing the distribution of hard core pornography.


Homosexuality and Gay Marriage

Over the past few decades, disputes over homosexuality and gay marriage laws have been particularly prominent. From the founding of the U.S., all states enacted sodomy laws that prohibited anal sex; these were originally adapted from earlier British “buggery laws” that carried the death penalty. State sodomy laws typically applied to both male-male and male-female situations, but they were usually enforced only with violent sexual crimes such as sexual assault and rape. Over time, penalties were reduced from death to fines and imprisonment. When the gay rights movement began in the 1960s and several states repealed their sodomy laws altogether, other conservative states rewrote their sodomy laws to apply to only homosexual activity. In a 1986 sodomy case, Bowers v. Hardwick, the Supreme Court upheld the rights of states to have sodomy laws, maintaining that nothing in the Constitution "would extend a fundamental right to homosexuals to engage in acts of consensual sodomy." However, the Supreme Court reversed its decision in the landmark case Lawrence v. Texas (2003). According to that ruling, state laws criminalizing homosexual activity are unconstitutional since they violate the right to privacy. The court noted that public opinion, both in the U.S. and Europe, had turned against sodomy laws and there was a growing sense that the rights of homosexuals should be protected:


In the United States criticism of Bowers has been substantial and continuing, disapproving of its reasoning in all respects, not just as to its historical assumptions. . . . To the extent Bowers relied on values we share with a wider civilization, it should be noted that the reasoning and holding in Bowers have been rejected elsewhere. The European Court of Human Rights has followed not Bowers. . . . Other nations, too, have taken action consistent with an affirmation of the protected right of homosexual adults to engage in intimate, consensual conduct. . . . There has been no showing that in this country the governmental interest in circumscribing personal choice is somehow more legitimate or urgent. [Lawrence v. Texas, 2003, majority opinion]


Ultimately, the Lawrence decision defends the privacy of homosexuals in their bedrooms as a constitutionally protected liberty right, and the presumption is that this ruling will ultimately invalidate adultery and anti-fornication laws as well.

            Granting legal protection to private and consensual homosexual activity is one thing, but allowing gay couples to marry is another. Beginning in 2004 states began permitting same sex marriages. Defenders of such gay marriage legislation argued that it was a matter of justice: heterosexual couples can express their commitment to each other through marriage, and it is discriminatory to deny this to homosexuals. Marriage also grants couples a range of legal rights, such as to adopt children, inherit property, be on a family insurance policy, visit relatives in hospitals. On the other hand, critics of gay marriage legislation argued that marriage is a unique contract with religious and moral implications that has historically applied to only heterosexual couples; allowing gay couples to marry undermines the historic nature of the institution itself. Also, critics argue, children thrive better in households with heterosexual parents, and marriage should be about what’s in the best interests of children. Some states offered a compromise arrangement of “civil unions” which give gay couples a select set of legal rights, but not as many as full marriage.

            In reaction to the trend towards gay marriage, about 30 states banned same sex marriage, some with state constitution amendments. Aanticipating the gay marriage trend, in 1996 Congress passed the Defense of Marriage Act (DOMA), which limited the rights of legally married homosexuals. There were two central components to the law. First, gay marriages legalized in one state would not have to be acknowledged in another state; second, the federal government itself would not acknowledge gay marriages. The effect of this second stipulation was that gay couples, even when legally married in some states, could not receive any legal benefits of marriage at the federal level, such as social security or tax benefits.

            But in the 2013 Supreme Court case, U.S. v. Windsor, that all changed when the Court ruled in a 5-4 vote that DOMA was unconstitutional. In this case, Edith Windsor was legally married to another woman in Canada and they resided in New York, which recognizes same-sex marriages. When Windsor’s spouse died, the Federal IRS imposed a $363,053 estate tax on her since under the Defense of Marriage Act (1996) the Federal government does not acknowledge the legitimacy of same-sex marriages. The Supreme Court ruled in Windsor’s favor on the grounds that DOMA intruded into the rights of states that granted same sex marriages and made such marriages unequal. The Court wrote,


DOMA's principal effect is to identify a subset of state-sanctioned marriages and make them unequal. The principal purpose is to impose inequality, not for other reasons like governmental efficiency... By this dynamic DOMA undermines both the public and private significance of state-sanctioned same-sex marriages; for it tells those couples, and all the world, that their otherwise valid marriages are unworthy of federal recognition. This places same-sex couples in an unstable position of being in a second-tier marriage. The differentiation demeans the couple, whose moral and sexual choices the Constitution protects . . . and whose relationship the State has sought to dignify (U.S. v. Windsor, 2013).


While this did not legalize gay marriage throughout the country, it provided legal ammunition to challenge bans on same sex marriage at the state level, which resulted in the legalization of same-sex marriage in 35 states. Finally, in the 2015 Supreme Court case Obergefell v. Hodges, gay marriage was recognized as a Constitutional right, and required all 50 states to issue marriage licenses to same-sex couples. The Court argued,


The limitation of marriage to opposite-sex couples may long have seemed natural and just, but its inconsistency with the central meaning of the fundamental right to marry is now manifest. With that knowledge must come the recognition that laws excluding same-sex couples from the marriage right impose stigma and injury of the kind prohibited by our basic charter. (Obergefell v. Hodges, 2015)




It is common to depict moral controversies as a debate between conservative and liberal sides of the issue. This is so with sexual morality, and we will conclude with a brief consideration of the strengths and weaknesses of the two sides.


The Conservative Position

The conservative position regarding sex is that sexual activity should take place only between a man and a woman in a monogamous marriage. Nontraditional sexual practices such as premarital sex, homosexuality, adultery, and pornography are immoral and should be illegal. The main arguments for the conservative position are these:

            1. Natural law: sexual activity is for the purpose of procreation, and purely recreational sex is contrary to this natural aim. Human nature is not open-ended, and does not allow for a free-for-all of any conduct that we like. Our nature is defined by a larger human good that is reflected in many of our natural inclinations and functions. Sex is one of these: it is there for the continuation of the species, which for us involves a committed monogamous relation between one man and one woman. A criticism of this argument is that sexual activity serves a wider range of functions than mere procreation. It strengthens a couple’s relationship, enhances their feelings towards each other, and gives people a great sense of pleasure; these non-procreative functions apply to many nontraditional sexual practices as well as they do to traditional ones.

            2. Family values: Nontraditional sexual practices damage the social institution of marriage and its commitment to raising children in the most stable home situation. Society is not just about the desires of individual adults, but also about raising the next generation of citizens who will carry on in our footsteps and hopefully improve on what we have done. Nontraditional sexual practices weaken family units by leading to single parenthood, same sex parenthood, divorces, marital conflict, all of which reduce a child’s opportunity to thrive. A criticism of this argument is that children thrive just as well in many nontraditional family settings as they do in traditional ones. Certainly, all parents should give the highest priority to their children’s wellbeing, but there are ways of doing this without eliminating nontraditional sexual practices.

            3. Harm from STDs and pregnancy: Nontraditional sexual practices are accompanied by serious harms, such as sexually transmitted diseases, unwanted pregnancies, and psychological feelings of shame. To the extent that we judge the rightness of our conduct based on their consequences, the negative side effects of nontraditional sexual practices are enormous, and not worth the risk. A criticism of this argument is that there are ways of reducing the risks associated with nontraditional sexual practices. Safe sex reduces STDs, contraception use reduces unwanted pregnancies, avoiding one night stands reduces feelings of shame. With the right type of risk management, the benefits of many nontraditional sexual practices may outweigh their potential harms.


The Liberal Position

The liberal position regarding sex is that any type of non-harmful or non-exploitive sexual conduct is morally permissible and should be legal, including premarital sex, homosexuality, adultery, and pornography. The main arguments for the liberal position are these:

            1. Freedom: One of our most important values is the freedom of individuals to act as they choose, as long as their actions do not harm others, and this includes nontraditional sexual activity. Toleration of differences is an important component of a free society, and, while conservative critics might not especially like nontraditional sexual practices, they are not justified in attempting to suppress them. A criticism of this argument is that the freely chosen sexual actions of nontraditionalists may have a negative impact on the lives of traditionalists. Sexual permissiveness pervades all aspects of culture including movies, television shows, music, internet sites. This compromises the abilities of traditional parents to raise their children in a way that conforms to more traditional sexual values.

            2. Cultural relativism: Like many social values, moral attitudes about sexual practices vary dramatically from culture to culture, and our society has already grown to accept nontraditional sexual practices as a social norm. It makes no sense to hold people to a 19th century standard of sexual morality when our culture has shifted to one that is so much more sexually permissive. A criticism of this argument is that just because everyone is doing it does not mean that society should approve of it. True, people’s sexual attitudes and behavior do change with cultural trends, but traditional sexual values have withstood the test of time and remain an important standard of morality amid cultural shifts.

            3. Different Strokes: Some people are not suited for traditional monogamous marriage, and sexual alternatives should be available to them. To the extent that homosexuality is biologically grounded, it is not realistic to expect gays to change their sexual orientation—any more than it is possible for heterosexuals to change theirs. The average age for marriage is now around age 27, and it is unrealistic for young couples to postpone sex until then, and statistics show that hardly anyone does anyway. Pornography can also make that long waiting time more manageable. Some marriages are beyond repair, but the couples may need to stay together for financial reasons or because of children. Extramarital options can make their lives more fulfilling. A criticism of this argument is that traditional monogamous marriage is a viable option for most people. Some may opt out if they find it too restricting, but that does not mean society should approve of every sexual activity that nontraditionalists choose to engage in.


A Middle Ground

While disputes over sexual morality can get heated, there are several opportunities for compromise, and the U.S. has already embraced some of these. The most pervasive nontraditional sexual practice is premarital sex, and people largely approve of it. The most potentially damaging nontraditional sexual practice is adultery, and people largely condemn it. Pornography is widely used, and, though soft core forms are Constitutionally protected, hard core forms are not, and child pornographers are actively prosecuted. While people are divided over the morality of homosexuality, there is growing recognition of the biological factors driving homosexual orientation. In the spirit of toleration, the most important concession is the decriminalization of homosexuality and legalization of same-sex marriage, and this has now been done. Thus, traditionalists can still disapprove of these changes if they so choose, yet homosexuals are protected by law.


READING 1: SEX ONLY FOR REPRODUCTION (from Thomas Aquinas, Summa Contra Gentiles)


Unnaturalness of Fornication (3.122)

So appears the foolishness of those who say that simple fornication is not a sin. For they say the following. Given a woman free from a husband, and under no control of father or any other person, if anyone approaches her with her consent, he does her no wrong, because she is pleased so to act, and has the disposal of her own person: nor does he do any wrong to another, for she is under no one’s control: therefore there appears no sin. Nor does it seem to be a sufficient answer to say that she wrongs God, for God is not offended by us except by what we do against our own good (Chap. 121): but it does not appear that this conduct is against man’s good: hence no wrong seems to be done to God thereby. In like manner also it does not appear a sufficient answer, that wrong is thereby done to one’s neighbor, who is scandalized: for sometimes a neighbor is scandalized by what of itself is not a sin, in which case the sin is only incidental: but the question is not whether fornication is a sin incidentally, but whether it is a sin ordinarily and in itself.

            We must seek a solution to the above arguments. It has been said (Chap. 16.64) that God has care of everything according to that which is good for it. Now it is good for everything to gain its end, and evil for it to be diverted from its proper end. But as it is with the whole so also is it with the parts; our position then should be that every part of man and every act of his may attain its proper end. Now though semen is superfluous for the preservation of the individual, yet it is necessary to him for the propagation of the species. Other excretions, such as excrement, urine, sweat, and the like, are needful for no further purpose: hence the only good that comes to man regarding them is by their removal from the body. But that is not the object in the emission of semen, but rather the profit of generation, to which the union of the sexes is directed. Further, the generation of man would be useless unless appropriate nurturing followed, without which the offspring generated could not survive. The emission of semen then ought to be directed so that both the proper generation may result and the education of the offspring be secured.

            Hence it is clear that every emission of semen is contrary to the good of man, which takes place in a way whereby generation is impossible. And if this is done on purpose, it must be a sin. That is, it is a sin when generation is impossible in itself as is the case in every emission of semen without the natural union of male and female. For this reason such sins are called “sins against nature.” But if it is by accident that generation cannot follow from the emission of semen, the act is not against nature on that account, nor is it sinful; the case of the woman being barren would be a case in point.


Naturalness of Marriage

Likewise it must be against the good of man for semen to be emitted under conditions which, allowing generation to result, nevertheless prevent the proper education of the offspring. We observe that in those animals, dogs for instance, in which the female by herself suffices for the rearing of the offspring, the male and female stay no time together after the performance of the sexual act. But with all animals in which the female by herself does not suffice for the rearing of the offspring, male and female dwell together after the sexual act so long as is necessary for the rearing and training of the offspring. This appears in birds, whose young are incapable of finding their own food immediately when they are hatched: for since the bird does not suckle her young with milk, according to the provision made by nature in quadrupeds, but has to seek food abroad for her young, and therefore keep them warm in the period of feeding, the female could not do this duty all alone by herself: hence divine providence has put in the male a natural instinct or standing by the female for the rearing of the brood. Now in the human species the female is clearly insufficient of herself for the rearing of the offspring, since the need of human life makes many demands, which cannot be met by one parent alone. Hence the fitness of human life requires man to stand by woman after the sexual act is done, and not to go off at once and form connections with anyone he meets, as is the way with fornicators. Nor is this reasoning evaded by the fact of some particular woman having wealth and power enough to nourish her offspring all by herself: for in human acts the line of natural rightness is not drawn to suit the accidental variety of the individual, but the properties common to the whole species.

            A further consideration is, that in the human species the young need not only bodily nutrition, as animals do, but also the training of the soul. Other animals have their natural instincts to provide for themselves: but man lives by reason, which takes the experience of a long time to arrive at discretion. Hence children need instruction by the confirmed experience of their parents: nor are they capable of such instruction as soon as they are born, but after a long time, the time in fact taken to arrive at the years of discretion. For this instruction again a long time is needed; and then moreover, because of the assaults of passion, whereby the judgment of prudence is thwarted, there is need not of instruction only, but also of repression. For this purpose the woman by herself is not competent, but at this point especially there is required the accompaniment of the man, in whom there is at once reason more perfect to instruct, and force more potent to chastise. Therefore in the human race the advancement of the young in good must last, not for a short time, as in birds, but for a long period of life. Hence, whereas it is necessary in all animals for the male to stand by the female for such time as the father’s accompaniment is required for bringing up of the offspring, it is natural for man to be tied to the society of one fixed woman for a long period, not a short one. This social tie we call marriage. Marriage then is natural to man, and an irregular connection outside of marriage is contrary to the good of man; and therefore fornication must be sinful.

            Nor yet should it be counted a slight sin for one to procure the emission of semen irrespective of the proper purpose of generation and rearing of issue, on the pretence that it is a slight sin, or no sin at all, to apply any part of one’s body to another use than that to which it is naturally ordained—as if, for example, one were to walk on his hands, or do with his feet something that ought to be done with his hands. The answer is that by such irregular applications as those mentioned the good of man is not greatly injured: but the irregular emission of semen is repugnant to the good of nature, which is the conservation of the species. Hence, after the sin of murder, whereby a human nature already in actual existence is destroyed, this sort of sin seem to hold the second place, whereby the generation of human nature is precluded. . . .

            The above assertions are confirmed by divine authority. The unlawfulness of any emission of semen, upon which offspring cannot be consequent, is evident from such texts as these: Thou shalt not lie with mankind as with womankind: Thou shalt not lie with any beast (Levit. 18.22-23): Nor the effeminate, nor sodomites, shall possess the kingdom of God (1 Cor. 6.10). The unlawfulness of fornication and of all connection with any other woman than one’s own wife is clear from Deut. 23.17: There shall be no whore among the daughters of Israel, nor whoremonger among the sons of Israel: Keep thyself from all fornication, and beyond thine own wife suffer not the charge of knowing another (Job. 4.13): Fly fornication (1 Cor. 6.18).

            Hereby is refuted the error of those who say that there is no more sin in the emission of semen than in the ejection of other superfluous products from the body.


Against Divorce (3.123)

Looking at the matter rightly, one must see that the above mentioned reasons not only support a long duration for that natural human partnership of male and female, which we call marriage, but further imply that the partnership ought to be lifelong.

            1. Property is a means to the preservation of human life. And because natural life cannot be preserved in one and the same person of the father living on for all time, nature arranges for its preservation by the son succeeding his father in likeness of species. For this reason, it is appropriate that the son should succeed his father in his property. It is natural therefore that the father’s interest in his son should continue to the end of his life, and that father and mother should dwell together to the end.

            2. Woman is taken into partnership with man for the need of childbearing: therefore when the fertility and beauty of woman ceases, there is a prohibition against her being taken up by another man. If then a man, taking a woman to wife in the time of her youth, when beauty and fertility remain with her, could send her away when she was advanced in years, he would do the woman harm, contrary to natural equity.

            3. It is manifestly absurd for the woman to be able to send away the man, seeing that woman is naturally subject to the rule of man, and it is not in the power of a subject to run away from control. It being then against the order of nature for the woman to be allowed to desert the man, if the man were allowed to desert the woman, the partnership of man and woman would not be on fair terms, but would be a sort of slavery on the woman’s side.

            4. Men show a natural anxiety to be sure of their own offspring; and whatever stands in the way of that assurance runs counter to the natural instinct of the race. But if the man could send away the woman, or the woman the man, and form a connection with another, certainty as to parentage would be difficult, when a woman had intercourse first with one man and then with another. . . .


Against Polygamy (3.124)

One general reason holds for all animals, which is this, that every animal desires free enjoyment of the pleasure of sexual union as of eating: which freedom is impeded by there being either several males to one female, or the other way about: and therefore animals fight alike for food and for sexual jealousy. But in men there is a special reason, inasmuch as man naturally desires to be sure of his own offspring. But here a difference comes in. Both of the above mentioned reasons hold for the case of the cohabitation of one female with several males: but the second reason does not hold against the cohabitation of one male with several females,—I mean certainty in point of parentage is not in that case prevented. But the first reason makes against it: for as the free enjoyment of the female is taken from the male, if the female has another partner, so the same free enjoyment is taken from the female, if the male has more than one partner.

            2. In every species of animal in which the father takes any interest in the offspring, one male keeps company with one female only, as in all birds that rear their young in common: for one male could not avail for several females as a helper in the rearing of their offspring: whereas in animals in which the males take no interest in the offspring, one male consorts with several females promiscuously, and the female with several males, as appears in dogs, poultry, and the like. But the male’s interest in the offspring is greater in the human species than in any other.

            3 and 4. The reason why a wife is not allowed more than one husband at a time is because otherwise paternity would be uncertain. If then while the wife has one husband only, the husband has more than one wife, there will not be a friendship of equality on both sides, friendship consisting in a certain equality. There will not be the friendship of a free man with a free woman, but a sort of friendship of a slave with her master. The husband might well be allowed a plurality of wives, if the understanding were allowable, that the friendship of each with him was not to be that of a free woman with a free man but of a slave with her master. And this is borne out by experience: for among men that keep many wives the wives are counted as menials.

            5. From one man having several wives there arises domestic discord, as experience shows.

            Hence it is said: They shall be two in one flesh (Gen. 2.24).


Against Incest (3.125)

Since in marriage there is a union of different persons, those persons who ought to consider themselves as one because of their being of one stock, are properly excluded from intermarrying, that they may love one another more ardently on the mere ground of their common origin.

            2. Since the intercourse of man and wife carries with it a certain natural shame, those persons should be prevented from such intercourse who owe one another a mutual reverence on account of the tie of blood. And this is the reason touched on in Leviticus 18.

            3. Excessive indulgence in sexual pleasures makes for the corruption of good manners: for such pleasures of all others most absorb the mind and hinder the right exercise of reason. But such excessive indulgence would result, if the intercourse of the sexes were allowed among persons who must necessarily dwell under the same roof, where the occasion of such intercourse could not be withdrawn.

            5. In human society the widening of friendships is of the first importance. That is done by the marriage tie being formed with strangers. . . .


READING 2: THE RIGHT OF SAME-SEX COUPLES TO MARRY (from Obergefell v. Hodges, 2015)


This analysis compels the conclusion that same-sex couples may exercise the right to marry. The four principles and traditions to be discussed demonstrate that the reasons marriage is fundamental under the Constitution apply with equal force to same-sex couples.


Marriage Choice inherent in Individual Autonomy

A first premise of the Court’s relevant precedents is that the right to personal choice regarding marriage is inherent in the concept of individual autonomy. This abiding connection between marriage and liberty is why Loving invalidated interracial marriage bans under the Due Process Clause. . . . Like choices concerning contraception, family relationships, procreation, and childrearing, all of which are protected by the Constitution, decisions concerning marriage are among the most intimate that an individual can make. . . . Indeed, the Court has noted it would be contradictory “to recognize a right of privacy with respect to other matters of family life and not with respect to the decision to enter the relationship that is the foundation of the family in our society.” . . .

            Choices about marriage shape an individual’s destiny. As the Supreme Judicial Court of Massachusetts has explained, because “it fulfils yearnings for security, safe haven, and connection that express our common humanity, civil marriage is an esteemed institution, and the decision whether and whom to marry is among life’s momentous acts of self-definition.” . . . .

            The nature of marriage is that, through its enduring bond, two persons together can find other freedoms, such as expression, intimacy, and spirituality. This is true for all persons, whatever their sexual orientation. . . . . There is dignity in the bond between two men or two women who seek to marry and in their autonomy to make such profound choices. . . . (“[T]he freedom to marry, or not marry, a person of another race resides with the individual and cannot be infringed by the State”).


Two-Person Union of Highest Importance to Committed Individuals

A second principle in this Court’s jurisprudence is that the right to marry is fundamental because it supports a two-person union unlike any other in its importance to the committed individuals. This point was central to Griswold v. Connecticut, which held the Constitution protects the right of married couples to use contraception. . . . Suggesting that marriage is a right “older than the Bill of Rights,” Griswold described marriage this way:

            “Marriage is a coming together for better or for worse, hopefully enduring, and intimate to the degree of being sacred. It is an association that promotes a way of life, not causes; a harmony in living, not political faiths; a bilateral loyalty, not commercial or social projects. Yet it is an association for as noble a purpose as any involved in our prior decisions. ” . . .

            And in Turner, the Court again acknowledged the intimate association protected by this right, holding prisoners could not be denied the right to marry because their committed relationships satisfied the basic reasons why marriage is a fundamental right. The right to marry thus dignifies couples who “wish to define themselves by their commitment to each other.” . . . Marriage responds to the universal fear that a lonely person might call out only to find no one there. It offers the hope of companionship and understanding and assurance that while both still live there will be someone to care for the other.

            As this Court held in Lawrence, same-sex couples have the same right as opposite-sex couples to enjoy intimate association. Lawrence invalidated laws that made same-sex intimacy a criminal act. And it acknowledged that “[w]hen sexuality finds overt expression in intimate conduct with another person, the conduct can be but one element in a personal bond that is more enduring.” . . . But while Lawrence confirmed a dimension of freedom that allows individuals to engage in intimate association without criminal liability, it does not follow that freedom stops there. Outlaw to outcast may be a step forward, but it does not achieve the full promise of liberty.


Right to Marry Safeguards Children and Families

A third basis for protecting the right to marry is that it safeguards children and families and thus draws meaning from related rights of childrearing, procreation, and education. . . . The Court has recognized these connections by describing the varied rights as a unified whole: “[T]he right to ‘marry, establish a home and bring up children’ is a central part of the liberty protected by the Due Process Clause.” . . . Under the laws of the several States, some of marriage’s protections for children and families are material. But marriage also confers more profound benefits. By giving recognition and legal structure to their parents’ relationship, marriage allows children “to understand the integrity and closeness of their own family and its concord with other families in their community and in their daily lives.” . . . Marriage also affords the permanency and stability important to children’s best interests. . . .

            As all parties agree, many same-sex couples provide loving and nurturing homes to their children, whether biological or adopted. And hundreds of thousands of children are presently being raised by such couples. . . . Most States have allowed gays and lesbians to adopt, either as individuals or as couples, and many adopted and foster children have same-sex parents. . . . This provides powerful confirmation from the law itself that gays and lesbians can create loving, supportive families.

            Excluding same-sex couples from marriage thus conflicts with a central premise of the right to marry. Without the recognition, stability, and predictability marriage offers, their children suffer the stigma of knowing their families are somehow lesser. They also suffer the significant material costs of being raised by unmarried parents, relegated through no fault of their own to a more difficult and uncertain family life. The marriage laws at issue here thus harm and humiliate the children of same-sex couples. . . .

            That is not to say the right to marry is less meaningful for those who do not or cannot have children. An ability, desire, or promise to procreate is not and has not been a prerequisite for a valid marriage in any State. In light of precedent protecting the right of a married couple not to procreate, it cannot be said the Court or the States have conditioned the right to marry on the capacity or commitment to procreate. The constitutional marriage right has many aspects, of which childbearing is only one.


Marriage is a Keystone of Social Order and Receives State Benefits

Fourth and finally, this Court’s cases and the Nation’s traditions make clear that marriage is a keystone of our social order. Alexis de Tocqueville recognized this truth on his travels through the United States almost two centuries ago:


“There is certainly no country in the world where the tie of marriage is so much respected as in America . . . [W]hen the American retires from the turmoil of public life to the bosom of his family, he finds in it the image of order and of peace . . . . [H]e afterwards carries [that image] with him into public affairs.” . . .


In Maynard v. Hill . . . the Court echoed de Tocqueville, explaining that marriage is “the foundation of the family and of society, without which there would be neither civilization nor progress.” Marriage, the Maynard Court said, has long been “ ‘a great public institution, giving character to our whole civil polity.’ ” Id., at 213. This idea has been reiterated even as the institution has evolved in substantial ways over time, superseding rules related to parental consent, gender, and race once thought by many to be essential. . . . Marriage remains a building block of our national community.

            For that reason, just as a couple vows to support each other, so does society pledge to support the couple, offering symbolic recognition and material benefits to protect and nourish the union. Indeed, while the States are in general free to vary the benefits they confer on all married couples, they have throughout our history made marriage the basis for an expanding list of governmental rights, benefits, and responsibilities. These aspects of marital status include: taxation; inheritance and property rights; rules of intestate succession; spousal privilege in the law of evidence; hospital access; medical decisionmaking authority; adoption rights; the rights and benefits of survivors; birth and death certificates; professional ethics rules; campaign finance restrictions; workers’ compensation benefits; health insurance; and child custody, support, and visitation rules. . . . Valid marriage under state law is also a significant status for over a thousand provisions of federal law. . . . The States have contributed to the fundamental character of the marriage right by placing that institution at the center of so many facets of the legal and social order.

            There is no difference between same- and opposite-sex couples with respect to this principle. Yet by virtue of their exclusion from that institution, same-sex couples are denied the constellation of benefits that the States have linked to marriage. This harm results in more than just material burdens. Same-sex couples are consigned to an instability many opposite-sex couples would deem intolerable in their own lives. As the State itself makes marriage all the more precious by the significance it attaches to it, exclusion from that status has the effect of teaching that gays and lesbians are unequal in important respects. It demeans gays and lesbians for the State to lock them out of a central institution of the Nation’s society. Same-sex couples, too, may aspire to the transcendent purposes of marriage and seek fulfillment in its highest meaning.


Exclusion of Same-Sex Marriage Inconsistent with the Meaning of the Right to Marry

            The limitation of marriage to opposite-sex couples may long have seemed natural and just, but its inconsistency with the central meaning of the fundamental right to marry is now manifest. With that knowledge must come the recognition that laws excluding same-sex couples from the marriage right impose stigma and injury of the kind prohibited by our basic charter.

            Objecting that this does not reflect an appropriate framing of the issue, the respondents refer to Washington v. Glucksberg, . . . which called for a “careful description” of fundamental rights. They assert the petitioners do not seek to exercise the right to marry but rather a new and nonexistent “right to same-sex marriage.” Brief for Respondent in . . . Glucksberg did insist that liberty under the Due Process Clause must be defined in a most circumscribed manner, with central reference to specific historical practices. Yet while that approach may have been appropriate for the asserted right there involved (physician-assisted suicide), it is inconsistent with the approach this Court has used in discussing other fundamental rights, including marriage and intimacy. Loving did not ask about a “right to interracial marriage”; Turner did not ask about a “right of inmates to marry”; and Zablocki did not ask about a “right of fathers with unpaid child support duties to marry.” Rather, each case inquired about the right to marry in its comprehensive sense, asking if there was a sufficient justification for excluding the relevant class from the right. . . .

            That principle applies here. If rights were defined by who exercised them in the past, then received practices could serve as their own continued justification and new groups could not invoke rights once denied. This Court has rejected that approach, both with respect to the right to marry and the rights of gays and lesbians. . . .

            The right to marry is fundamental as a matter of history and tradition, but rights come not from ancient sources alone. They rise, too, from a better informed understanding of how constitutional imperatives define a liberty that remains urgent in our own era. Many who deem same-sex marriage to be wrong reach that conclusion based on decent and honorable religious or philosophical premises, and neither they nor their beliefs are disparaged here. But when that sincere, personal opposition becomes enacted law and public policy, the necessary consequence is to put the imprimatur of the State itself on an exclusion that soon demeans or stigmatizes those whose own liberty is then denied. Under the Constitution, same-sex couples seek in marriage the same legal treatment as opposite-sex couples, and it would disparage their choices and diminish their personhood to deny them this right.




Please answer all of the following questions.


1. What are some of the features of animal sexual behavior in primates?

2. What are some of the features of human sexual behavior?

3. What is Aquinas’s argument for his procreation-only view of sex and a criticism of it?

4. What is Kant’s argument against non-traditional sexual practices and a criticism of it?

5. What is Bentham’s utilitarian argument for some non-traditional sexual practices?

6. What is Paley’s utilitarian argument against non-traditional sexual practices?

7. What is De Sade’s natural law view of sexual morality and what are the two problems with it?

8. What is Goldman’s personal freedom view of sexual morality and a criticism of it?

9. Explain the legal status of contraception in both the Comstock Act (1873) and the Supreme Court case Griswold v. Connecticut (1965).

10. What is the legal status of pornography ownership by individuals as established by Stanley v. Georgia (1969), and what are the restrictions on that?

11. What is the Miller test for Obscenity established in Miller v. California (1973)?

12. Explain DOMA (Defense of Marriage Act).

13. Explain the legal status of homosexuality as established in Lawrence v. Texas (2003), U.S. v. Windsor (2013), and Obergefell v. Hodges (2015).

14. What are the criticisms of the three conservative arguments regarding sex?

15. What are the criticisms of the three liberal arguments regarding sex?

[Reading 1: Aquinas]

16. What is Aquinas’s argument for the naturalness of marriage?

17. What are Aquinas’s arguments against divorce?

18. What are Aquinas’s arguments against polygamy?

[Reading 2: Obergefell v. Hodges]

19. What, according to the Supreme Court, are the four principles upon which same-sex marriage is based?

20. What, according to the Supreme Court, is wrong with basing rights solely on the past?

[Question for Analysis]

21. Pick any one of the following views in this chapter and criticize it in a minimum of 150 words. Aquinas’s procreation-only view of sex; Kant’s view of non-traditional sexual practices; Paley’s view of non-traditional sexual practices; De Sade’s natural law view of sexual morality; Goldman’s personal freedom view of sexual morality; the ruling in one of the Supreme Court cases on sexual issues.