[From "Philosophy and Sex", 3rd ed., Baker, Wininger, and Elliston, eds. (New York: Prometheus Books, 1998)].
Many discussions of the enforcement of morality by the law take as illustrative of the problem under consideration the regulation of various types of sexual behavior by the criminal law. It was, for example, the Wolfenden Report's recommendations concerning homosexuality and prostitution that led Lord Devlin to compose his now famous lecture "The Enforcement of Morals." And that lecture in turn provoked important philosophical responses from H. L. A. Hart, Ronald Dworkin, and others.
Much, if not all, of the recent philosophical literature on the enforcement of morals appears to take for granted the immorality of the sexual behavior in question. The focus of discussion, at least, is on whether such things as homosexuality, prostitution, and adultery ought to be made illegal even if they are immoral, and not on whether they are immoral.
I propose in this paper to consider the latter, more neglected topic, that of sexual morality, and to do so in the following fashion. I shall consider just one kind of behavior that is often taken to be a case of sexual immorality-adultery. I am interested in pursuing at least two questions. First, I want to explore the question of in what respects adulterous behavior falls within the domain of morality at all, for this surely is one of the puzzles one encounters when considering the topic of sexual morality. It is often hard to see on what grounds much of the behavior is deemed to be either moral or immoral, for example, private homosexual behavior between consenting adults. I have purposely selected adultery because it seems a more plausible candidate for moral assessment than many other kinds of sexual behavior.
The second question I want to examine is that of what is to be said about adultery if we are not especially concerned to stay within the area of its morality. I shall endeavor, in other words, to identify and to assess a number of the major arguments that might be advanced against adultery. I believe that they are the chief arguments that would be given in support of the view that adultery is immoral, but I think they are worth considering even if some of them turn out to be nonmoral arguments and considerations.
A number of the issues involved seem to me to be complicated and difficult. In a number of places I have at best indicated where further philosophical exploration is required, without having successfully conducted the exploration myself. This essay may very well be more useful as an illustration of how one might begin to think about the subject of sexual morality than as an elucidation of important truths about the topic.
Before I turn to the arguments themselves, there are two preliminary points that require some clarification. Throughout the paper I shall refer to the immorality of such things as breaking a promise, deceiving someone, and so on. In a very rough way I mean by this that there is something morally wrong in doing the action in question. I mean that the action is, in a strong sense of "prima facie," prima facie wrong or unjustified. I do not mean that it may never be right or justifiable to do the action just that the fact that it is an action of this description always counts against the rightness of the action. I leave entirely open the question of what it is that makes actions of this kind immoral in this sense of "immoral."
The second preliminary point concerns what is meant or implied by the concept of adultery. I mean by "adultery" any case of extramarital sex, and I want to explore the arguments for and against extramarital sex, undertaken in a variety of morally relevant situations. Someone might claim that the concept of adultery is conceptually connected with the concept of immorality and that to characterize behavior as adulterous is already to characterize it as immoral or unjustified in the sense described above. There may be something to this. Hence the importance of making it clear that I want to discuss extramarital sexual relations. If they are always immoral, this is something that must be shown by argument. If the concept of adultery does in some sense entail or imply immorality, I want to ask whether that connection is a rationally based one. If not all cases of extramarital sex are immoral (again, in the sense described above), then the concept of adultery should either be weakened accordingly or restricted to those classes of extramarital sex for which the predication of immorality is warranted.
One argument for the immorality of adultery might go something like this: What makes adultery immoral is that it involves the breaking of a promise, and what makes adultery seriously wrong is that it involves the breaking of an important promise. For, so the argument might continue, one of the things the two parties promise each other when they get married is that they will abstain from sexual relationships with third parties. Because of this promise both spouses quite reasonably entertain the expectation that the other will behave in conformity with it. Hence, when one of them has sexual intercourse with a third party, he or she breaks that promise about sexual relationships that was made when the marriage was entered into and defeats the reasonable expectations of exclusivity entertained by the spouse.
In many cases the immorality involved in breaching the promise relating to extramarital sex may be a good deal more serious than that involved in the breach of other promises. This is so because adherence to this promise may be of much greater importance to them than is adherence to many of the other promises given or received by them in their lifetime. The breaking of this promise may be much more hurtful and painful than is typically the case.
Why is this so? To begin with, it may have been difficult for the nonadulterous spouse to have kept the promise. Hence that spouse may feel the unfairness of having restrained himself or herself in the absence of reciprocal restraint having been exercised by the adulterous spouse. In addition, the spouse may perceive the breaking of the promise as an indication of a kind of indifference on the part of the adulterous spouse. If you really cared about me and my feelings, the spouse might say, you would not have done this to me. And third, and related to the above, the spouse may see the act of sexual intercourse with another as a sign of affection for the other person and as an additional rejection of the nonadulterous spouse as the one who is loved by the adulterous spouse. It is not just that the adulterous spouse does not take the feelings of the nonadulterous spouse sufficiently into account; the adulterous spouse also indicates through the act of adultery affection for someone other than the nonadulterous spouse. I will return to these points later. For the present it is sufficient to note that a set of arguments can be developed in support of the proposition that certain kinds of adultery are wrong just because they involve the breach of a serious promise that, among other things, leads to the intentional infliction of substantial pain on one spouse by the other.
Another argument for the immorality of adultery focuses not on the existence of a promise of sexual exclusivity but on the connection between adultery and deception. According to this argument adultery involves deception. And because deception is wrong, so is adultery.
Although it is certainly not obviously so, I shall simply assume in this essay that deception is always immoral. Thus, the crucial issue for my purposes is the asserted connection between extramarital sex and deception. Is it plausible to maintain, as this argument does, that adultery always involves deception and is, on that basis, to be condemned?
The most obvious person upon whom deceptions might be practiced is the nonparticipating spouse; and the most obvious thing about which the nonparticipating spouse can be deceived is the existence of the adulterous act. One clear case of deception is that of lying. Instead of saying that the afternoon was spent in bed with A, the adulterous spouse asserts that it was spent in the library with B or on the golf course with C.
There can also be deception even when no lies are told. Suppose, for instance, that a person has sexual intercourse with someone other than his or her spouse and just does not tell the spouse about it. Is that deception? It may not be a case of lying if, for example, he or she is never asked by the spouse about the situation. Still, we might say, it is surely deceptive because of the promises that were exchanged at marriage. As we saw earlier, these promises provide a foundation for the reasonable belief that neither spouse will engage in sexual relationships with any other person. Hence the failure to bring the fact of extramarital sex to the attention of the other spouse deceives that spouse about the present state of the marital relationship.
Adultery, in other words, can involve both active and passive deception. An adulterous spouse may just keep silent or, as is often the case, the spouse may engage in an increasingly complex way of life devoted to the concealment of the facts from the nonparticipating spouse. Lies, half-truths, clandestine meetings, and the like may become a central feature of the adulterous spouse's existence. These are things that can and do happen, and when they do they make the case against adultery an easy one. Still, neither active nor passive deception is inevitably a feature of an extramarital relationship.
It is possible, though, that a more subtle but pervasive kind of deceptiveness is a feature of adultery. It comes about because of the connection in our culture between sexual intimacy and certain feelings of love and affection. The point can be made indirectly by seeing that one way in which we can in our culture mark off our close friends from our mere acquaintances is through the kinds of intimacies that we are prepared to share with them. I may, for instance, be willing to reveal my very private thoughts and emotions to my closest friends or to my wife but to no one else. My sharing of these intimate facts about myself is, from one perspective, a way of making a gift to those who mean the most to me. Revealing these things and sharing them with those who mean the most to me is one means by which I create, maintain, and confirm those interpersonal relationships that are of most importance to me.
In our culture, it might be claimed, sexual intimacy is one of the chief currencies through which gifts of this sort are exchanged. One way to tell someone-particularly someone of the opposite sex-that you have feelings of affection and love for them is by allowing them, or sharing with them, sexual behaviors that one does not share with others. This way of measuring affection was certainly very much a part of the culture in which I matured. It worked something like this: If you were a girl, you showed how much you liked a boy by the degree of sexual intimacy you would allow. If you liked him only a little you never did more than kiss-and even the kiss was not very passionate. If you liked him a lot and if your feeling was reciprocated, necking and, possibly, petting were permissible. If the attachment was still stronger and you thought it might even become a permanent relationship, the sexual activity was correspondingly more intense and intimate, although whether it led to sexual intercourse depended on whether the parties (particularly the girl) accepted fully the prohibition on nonmarital sex. The situation for the boys was related but not exactly the same. The assumption was that males did not naturally link sex with affection in the way in which females did. However, since women did link sex with affection, males had to take that fact into account. That is to say, because a woman would permit sexual intimacies only if she had feelings of affection for the male and only if those feelings were reciprocated, the male had to have and express those feelings too, before sexual intimacies of any sort would occur.
The result was that the importance of a correlation between sexual intimacy and feelings of love and affection was taught by the culture and assimilated by those growing up in the culture. The scale of possible positive feelings toward persons of the other sex ran from casual liking, at one end, to the love that was deemed essential to, and characteristic of, marriage, at the other. The scale of possible sexual behavior ran from brief, passionless kissing or hand-holding, at one end, to sexual intercourse, at the other. And the correlation between the two scales was quite precise. As a result, any act of sexual intimacy carried substantial meaning with it, and no act of sexual intimacy was simply a pleasurable set of bodily sensations. Many such acts were, of course, more pleasurable to the participants because they were a way of saying what their feelings were. And sometimes they were less pleasurable for the same reason. The point is, however, that sexual activity was much more than mere bodily enjoyment. It was not like eating a good meal, listening to good music, lying in the sun, or getting a pleasant back rub. It was behavior that meant a great deal concerning one's feelings for persons of the opposite sex in whom one was most interested and with whom one was most involved. It was among the most authoritative ways in which one could communicate to another the nature and degree of one's affection.
If this sketch is even roughly right, then several things become somewhat clearer. To begin with, a possible rationale for many of the rules of conventional sexual morality can be developed. If, for example, sexual intercourse is associated with the kind of affection and commitment to another that is regarded as characteristic of the marriage relationship, then it is natural that sexual intercourse should be thought properly to take place between persons who are married to each other. And if it is thought that this kind of affection and commitment is only to be found within the marriage relationship, then it is not surprising that sexual intercourse should only be thought to be proper within marriage.
Related to what has just been said is the idea that sexual intercourse ought to be restricted to those who are married to each other, as a means by which to confirm the very special feelings that the spouses have for each other. Because our culture teaches that sexual intercourse means that the strongest of all feelings for each other are shared by the lovers, it is natural that persons who are married to each other should be able to say this to each other in this way. Revealing and confirming verbally that these feelings are present is one thing that helps to sustain the relationship; engaging in sexual intercourse is another.
In addition, this account would help to provide a framework within which to make sense of the notion that some sex is better than other sex. As I indicated earlier, the fact that sexual intimacy can be meaningful in the sense described tends to make it also the case that sexual intercourse can sometimes be more enjoyable than at other times. On this view, sexual intercourse will typically be more enjoyable if strong feelings of affection are present than it will be if it is merely "mechanical." This is so in part because people enjoy being loved, especially by those whom they love. Just as we like to hear words of affection, so we like to receive affectionate behavior. And the meaning enhances the independently pleasurable behavior.
More to the point, an additional rationale for the prohibition on extramarital sex can now be developed. For given this way of viewing the sexual world, extramarital sex will almost always involve deception of a deeper sort. If the adulterous spouse does not in fact have the appropriate feelings of affection for the extramarital partner, then the adulterous spouse is deceiving that person about the presence of such feelings. If, on the other hand, the adulterous spouse does have the corresponding feelings for the extramarital partner but not toward the nonparticipating spouse, the adulterous spouse is very probably deceiving the nonparticipating spouse about the presence of such feelings toward that spouse. Indeed, it might be argued, whenever there is no longer love between the two persons who are married to each other, there is deception just because being married implies both to the participants and to the world that such a bond exists. Deception is inevitable, the argument might conclude, because the feelings of affection that ought to accompany any act of sexual intercourse can only be held toward one other person at any given time in one's life. And if this is so, then the adulterous spouse always deceives either the partner in adultery or the nonparticipating spouse about the existence of such feelings. Thus extramarital sex involves deception of this sort and is for that reason immoral even if no deception vis-a-vis the occurrence of the act of adultery takes place.
What might be said in response to the foregoing arguments? The first thing that might be said is that the account of the connection between sexual intimacy and feelings of affection is inaccurate-not in the sense that no one thinks of things that way but in the sense that there is substantially more divergence of opinion than the account suggests. For example, the view I have delineated may describe reasonably accurately the concepts of the sexual world in which I grew up, but it does not capture the sexual Weltanschauung of today's youth at all. Thus, whether or not adultery implies deception in respect to feelings depends very much on the persons who are involved and the way they look at the "meaning" of sexual intimacy.
Second, the argument leaves unanswered the question of whether it is desirable for sexual intimacy to carry the sorts of messages described above. For those persons for whom sex does have these implications there are special feelings and sensibilities that must be taken into account. But it is another question entirely whether any valuable end-moral or otherwise-is served by investing sexual behavior with such significance. That is something that must be shown and not just assumed. It might, for instance, be the case that substantially more good than harm would come from a kind of demystification of sexual behavior -one that would encourage the enjoyment of sex more for its own sake and one that would reject the centrality both of the association of sex with love and of love with only one other person.
I regard these as two of the more difficult unresolved issues that our culture faces today in respect of thinking sensibly about the attitudes toward sex and love that we should try to develop in ourselves and in our children.
Much of the contemporary literature that advocates sexual liberation of one sort or another embraces one or the other of two different views about the relationship between sex and love. One view holds that sex should be separated from love and affection. To be sure, sex is probably better when the partners genuinely like and enjoy being with each other. But sex is basically an intensive, exciting sensuous activity that can be enjoyed in a variety of suitable settings with a variety of suitable partners. The situation in respect to sexual pleasure is no different from that of the person who knows and appreciates fine food and who can have a satisfying meal in any number of good restaurants with any number of congenial companions. One question that must be settled here is whether sex can be thus demystified; another, more important, question is whether it would be desirable to do so. What might we gain and what might we lose if we all lived in a world in which an act of sexual intercourse was no more or less significant or enjoyable than having a delicious meal in a nice setting with a good friend? The answer to this question lies beyond the scope of this essay.
The second view of the relationship between sex and love seeks to drive the wedge in a different place. On this view it is not the link between sex and love that needs to be broken, but rather the connection between love and exclusivity. For a number of the reasons already given it is desirable, so this argument goes, that sexual intimacy continue to be reserved to and shared with only those for whom one has very great affection. The mistake lies in thinking that any "normal" adult will have those feelings toward only one other adult during his or her lifetime-or even at any time in his or her life. It is the concept of adult love, not ideas about sex, that needs demystification. What are thought to be both unrealistic and unfortunate are the notions of exclusivity and possessiveness that attach to the dominant conception of love between adults in our culture and others. Parents of four, five, six, or even ten children can certainly claim, and sometimes claim correctly, that they love all of their children, that they love them all equally, and that it is simply untrue to their feelings to insist that the numbers involved diminish either the quantity or the quality of their love. If this is readily understandable in the case of parents and children, there is no necessary reason why it is an impossible or undesirable ideal in the case of adults. To be sure, there is probably a limit to the number of intimate, "primary" relationships that any person can maintain at any given time without affecting the quality of the relationship. But one adult ought surely to be able to love two, three, or even six other adults at any one time without that love being different in kind or degree from that of the traditional, monogamous, lifetime marriage. And between the individuals in these relationships, whether within a marriage or without, sexual intimacy is fitting and good.
The issues raised by a position such as the one described above are also surely worth exploring in detail and with care. Is there something to be called "sexual love" that is different from parental love or the nonsexual love of close friends? Is there something about love in general that links it naturally and appropriately with feelings of exclusivity and possession? Or is there something about sexual love, whatever that may be, that makes these feelings especially fitting? Once again, the issues are conceptual, empirical, and normative all at once: What is love? How could it be different? Would it be a good thing or a bad thing if it were different?
Suppose, though, that having delineated these problems we were now to pass them by. Suppose, moreover, that we were to be persuaded of the possibility and the desirability of weakening substantially either the links between sex and love or the links between sexual love and exclusivity. Would it not then be the case that adultery could be free from all of the morally objectionable features described thus far? To be more specific, let us imagine that a husband and wife have what is today sometimes characterized as an "open marriage." Suppose, that is, that they have agreed in advance that extramarital sex is-under certain circumstances-acceptable behavior for each to engage in. Suppose that as a result there is no impulse to deceive each other about the occurrence or nature of any such relationships and that no deception in fact occurs. Suppose, too, that there is no deception in respect to the feelings involved between the adulterous spouse and the extramarital partner. And suppose, finally, that one or the other or both of the spouses then have sexual intercourse in circumstances consistent with these understandings. Under this description, so the argument might conclude, adultery is simply not immoral. At a minimum adultery cannot very plausibly be condemned either on grounds that it involves deception or on grounds that it requires the breaking of a promise.
At least two responses are worth considering. One calls attention to the connection between marriage and adultery; the other looks to more instrumental arguments for the immorality of adultery. Both deserve further exploration.
One way to deal with the case of the "open marriage" is to question whether the two persons involved are still properly to be described as being married to each other. Part of the meaning of what it is for two persons to be married to each other, so this argument would go, is to have committed oneself to have sexual relationships only with one's spouse. Of course, it would be added, we know that that commitment is not always honored. We know that persons who are married to each other often do commit adultery. But there is a difference between being willing to make a commitment to marital fidelity, even though one may fail to honor that commitment, and not making the commitment at all. Whatever the relationship may be between the two individuals in the case just described, the absence of any commitment to sexual exclusivity requires the conclusion that their relationship is not a marital one. For a commitment to sexual exclusivity is a necessary but not a sufficient condition for the existence of a marriage.
Although there may be something to this suggestion, it is too strong as stated to be acceptable. To begin with it is doubtful that there are many, if any, necessary conditions for marriage; but even if there are, a commitment to sexual exclusivity is not such a condition.
To see that this is so, consider what might be taken to be some of the essential characteristics of a marriage. We might be tempted to propose that the concept of marriage requires the following: a formal ceremony of some sort in which mutual obligations are undertaken between two persons of the opposite sex; the capacity on the part of the persons involved to have sexual intercourse with each other; the willingness to have sexual intercourse only with each other; and feelings of love and affection between the two persons. The problem is that we can imagine relationships that are clearly marital and yet lack one or more of these features. For example, in our own society it is possible for two persons to be married without going through a formal ceremony, as in the common-law marriages recognized in some jurisdictions. It is also possible for two persons to get married even though one or both lacks the capacity to engage in sexual intercourse. Thus, two very elderly persons who have neither the desire nor the ability to have intercourse can nonetheless get married, as can persons whose sexual organs have been injured so that intercourse is not possible. And we certainly know of marriages in which love was not present at the time of the marriage, as, for instance, in marriages of state and marriages of convenience.
Counterexamples not satisfying the condition relating to the abstention from extramarital sex are even more easily produced. We certainly know of societies and cultures in which polygamy and polyandry are practiced, and we have no difficulty in recognizing these relationships as cases of marriages. It might be objected, though, that these are not counterexamples because they are plural marriages rather than marriages in which sex is permitted with someone other than one of the persons to whom one is married. But we also know of societies in which it is permissible for married persons to have sexual relationships with persons to whom they are not married, for example, temple prostitutes, concubines, and homosexual lovers. And even if we knew of no such societies, the conceptual claim would still, I submit, not be well taken. For suppose all of the other indicia of marriage were present: suppose the two persons were of the opposite sex; suppose they had the capacity and desire to have intercourse with each other; suppose they participated in a formal ceremony in which they understood themselves voluntarily to be entering into a relationship with each other in which substantial mutual commitments were assumed. If all these conditions were satisfied we would not be in any doubt as to whether or not the two persons were married, even though they had not taken on a commitment of sexual exclusivity and even though they had expressly agreed that extramarital sexual intercourse was a permissible behavior for each to engage in.
A commitment to sexual exclusivity is neither a necessary nor a sufficient condition for the existence of a marriage. It does, nonetheless, have this much to do with the nature of marriage-like the other indicia enumerated above, its presence tends to establish the existence of a marriage. Thus, in the absence of a formal ceremony of any sort an explicit commitment to sexual exclusivity would count in favor of regarding the two persons as married. The conceptual role of the commitment to sexual exclusivity can, perhaps, be brought out through the following example. Suppose we found a tribe that had a practice in which all the other indicia of marriage were present but in which the two parties were prohibited even from having sexual intercourse with each other. Moreover, suppose that sexual intercourse with others was clearly permitted. In such a case we would, I think, reject the idea that the two persons were married to each other, and we would describe their relationship in other terms, for example, as some kind of formalized, special friendship relation-a kind of heterosexual "blood-brother" bond.
Compare that case with the following one. Again suppose that the tribe had a practice in which all of the other indicia of marriage were present, but instead of a prohibition on sexual intercourse between the persons in the relationship there was no rule at all. Sexual intercourse was permissible with the person with whom one had this ceremonial relationship, but it was no more or less permissible than with a number of other persons to whom one was not so related (for instance, all consenting adults of the opposite sex). While we might be in doubt as to whether we ought to describe the persons as married to each other, we would probably conclude that they were married and that they simply were members of a tribe whose views about sex were quite different from our own.
What all of this shows is that a prohibition on sexual intercourse between the two persons involved in a relationship is conceptually incompatible with the claim that the two of them are married. The permissibility of intramarital sex is a necessary part of the idea of marriage. But no such incompatibility follows simply from the added permissibility of extramarital sex.
These arguments do not, of course, exhaust the arguments for the prohibition on extramarital sexual relations. The remaining argument that I wish to consider is-as I indicated earlier-a more instrumental one. It seeks to justify the prohibition by virtue of the role that it plays in the development and maintenance of nuclear families. The argument, or set of arguments, might, I believe, go something like this:
Consider first a far-fetched nonsexual example. Suppose a society were organized so that after some suitable age-say 18, 19, or 20-persons were forbidden to eat anything but bread and water with anyone but their spouse. Persons might still choose in such a society not to get married. Good food just might not be very important to them because they have underdeveloped taste buds. Or good food might be bad for them because there is something wrong with their digestive system. Or good food might be important to them, but they might decide that the enjoyment of good food would get in the way of the attainment of other things that were more important. But most persons would, I think, be led to favor marriage in part because they preferred a richer, more varied diet to one of bread and water. And they might remain married because the family was the only legitimate setting within which good food was obtainable. If it is important to have society organized so that persons will both get married and stay married, such an arrangement would be well suited to the preservation of the family, and the prohibitions relating to food consumption could be understood as fulfilling that function.
It is obvious that one of the more powerful human desires is the desire for sexual gratification. The desire is a natural one, like hunger and thirst, in the sense that it need not be learned in order to be present within us and operative on us. But there is in addition much that we do learn about what the act of sexual intercourse is like. Once we experience sexual intercourse ourselves-and, in particular, once we experience orgasm-we discover that it is among the most intensive, short-term pleasures of the body.
Because this is so it is easy to see how the prohibition on extramarital sex helps to hold marriage together. At least during that period of life when the enjoyment of sexual intercourse is one of the desirable bodily pleasures, persons will wish to enjoy those pleasures. If one consequence of being married is that one is prohibited from having sexual intercourse with anyone but one's spouse, then the spouses in a marriage are in a position to provide an important source of pleasure for each other that is unavailable to them elsewhere in the society.
The point emerges still more clearly if this rule of sexual morality is seen as being of a piece with the other rules of sexual morality. When this prohibition is coupled, for example, with the prohibition on nonmarital sexual intercourse, we are presented with the inducement both to get married and to stay married. For if sexual intercourse is only legitimate within marriage, then persons seeking that gratification that is a feature of sexual intercourse are furnished explicit social directions for its attainment, namely, marriage.
Nor, to continue the argument, is it necessary to focus exclusively on the bodily enjoyment that is involved. Orgasm may be a significant part of what there is to sexual intercourse, but it is not the whole of it. We need only recall the earlier discussion of the meaning that sexual intimacy has in our own culture to begin to see some of the more intricate ways in which sexual exclusivity may be connected with the establishment and maintenance of marriage as the primary heterosexual love relationship. Adultery is wrong, in other words, because a prohibition on extramarital sex is a way to help maintain the institutions of marriage and the nuclear family.
I am frankly not sure what we are to say about an argument such as the preceding one. What I am convinced of is that, like the arguments discussed earlier, this one also reveals something of the difficulty and complexity of the issues that are involved. So what I want now to do in the final portion of this essay is to try to delineate with reasonable precision several of what I take to be the fundamental, unresolved issues.
The first is whether this last argument is an argument for the immorality of extramarital sexual intercourse. What does seem clear is that there are differences between this argument and the ones considered earlier. The earlier arguments condemned adulterous behavior because it was behavior that involved breaking a promise, taking unfair advantage of or deceiving another. To the degree to which the prohibition on extramarital sex can be supported by arguments that invoke considerations such as these, there is little question but that violations of the prohibition are properly regarded as immoral. And such a claim could be defended on one or both of two distinct grounds. The first is that action such as promise-breaking and deception are simply wrong. The second is that adultery involving promise-breaking or deception is wrong because it involves the straightforward infliction of harm on another human being-typically the nonadulterous spouse-who has a strong claim not to have that harm so inflicted.
The argument that connects the prohibition on extramarital sex with the maintenance and preservation of the institution of marriage is an argument for the instrumental value of the prohibition. To some degree this counts, I think, against regarding all violations of the prohibition as obvious cases of immorality. This is so partly because hypothetical imperatives are less clearly within the domain of morality than are categorical ones, and even more because instrumental prohibitions are within the domain of morality only if the end that they serve or the way that they serve it is itself within the domain of morality.
What this should help us see, I think, is the fact that the argument that connects the prohibition on adultery with the preservation of marriage is at best seriously incomplete. Before we ought to be convinced by it, we ought to have reasons for believing that marriage is a morally desirable and just social institution. And such reasons are not quite as easy to find or as obvious as it may seem. For the concept of marriage is, as we have seen, both a loosely structured and a complicated one. There may be all sorts of intimate, interpersonal relationships that will resemble but not be identical with the typical marriage relationship presupposed by the traditional sexual morality. There may be a number of distinguishable sexual and loving arrangements that can all legitimately claim to be called marriages. The prohibitions of the traditional sexual morality may be effective ways to maintain some marriages and ineffective ways to promote and preserve others. The prohibitions of the traditional sexual morality may make good psychological sense if certain psychological theories are true, and they may be purveyors of immense psychological mischief if other psychological theories are true. The prohibitions of traditional sexual morality may seem obviously correct if sexual intimacy carries the meaning that the dominant culture has often ascribed to it, and they may seem equally bizarre if sex is viewed through the perspective of the counterculture. Irrespective of whether instrumental arguments of this sort are properly deemed moral arguments, they ought not fully convince anyone until questions such as these are answered.