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Adultery: Is It Ever Justified?

We examine the ethics of adultery—and you may be surprised!

In my first post on adultery, I avoided discussing the ethics of cheating. Well, I tried to, at least; it's hard to discuss a topic like that without lapsing into the morality of it, so here goes. (For those of you that read my post on the ethics of procrastination, some of the discussion of moral philosophy will sound familiar.)

At the risk of spoiling the ending, let me reassure you that we'll find that adultery is wrong—most of the time. (Maybe that's not such a reassurance.) It's almost never justified just because you really really want to get together with that hottie in your office or at your club (sorry). But it might be justified in extraordinary circumstances, which to some people, unfortunately, might be rather ordinary.

This post also makes a general point about ethics and moral philosophy, that they're really good for coming up with general rules and prohibitions which apply in most cases, but there are always exceptions to those "do shall nots." Ethical systems are great for helping you frame moral issues (which is how ethics is normally taught in the classroom), but in the end, judgment is essential for arriving at a final answer. And you can't teach judgment—you develop it over time.

Let's say Christine tells her best friend Sally that she's thinking of cheating on her husband. What would Sally say? Well, she might ask her friend why she's thinking of cheating. Did her husband cheat? Is he mean, cold, or distant to her? Has the romance left their marriage? All of these may—or may not—seem like relevant questions, even if in the end Sally says that cheating is wrong.

What would philosophers have to offer on the subject of cheating? I mean, listen to Sally—cheating is just plain wrong, isn't it? And our intuitions are definitely that cheating is wrong. Well, so is lying, but we can all think of situations in which we would lie, and we would justify it if asked. Even taking a life can be justified if done in self-defense, or to save another life. In philosophical theories of morality, there are few absolutes, which means no easy answers—but we do get to ask lots of good questions!

So what supports our intuitions that cheating is wrong? There are three obvious answers, which conveniently correspond to the three ethical schools we'll look at to answer the question.

Answer 1: Because it hurts your spouse.

How would you feel if your spouse cheated on you? Some of you may know this from experience, but I think we can all imagine it—it hurts! You've been betrayed and lied to, and you feel angry, depressed, unworthy, second-rate, unwanted. You want to lash out at the same time you want to crawl inside yourself and hide. Your spouse chose to seek out intimacy of one sort or another with another person-not you. That defines "sucks."

Sorry if I hit a nerve—believe me, that wasn't my intention. But I wanted to make the point that infidelity is very hurtful, and does real psychological, emotional, and spiritual damage to one's partner. And to philosophers who teach an ethical system known as utilitarianism, hurting people is wrong, period.

Utilitarians maintain that the morality of an action depends on the amount of utility it creates, which can be thought of (as seminal utilitarian Jeremy Bentham did) in terms of pleasure and pain (among other concepts). One action is morally better than another if it leads to a greater amount of pleasure (or lesser amount of pain), and the right action is the one that leads to the greatest amount of pleasure (compared to pain). Utilitarianism is based on a lot of common sense, but can be absurdly demanding as well—for instance, if the poor would benefit more from a dollar than you, extreme utilitarians (such as Peter Singer) may demand that you give all of your money away to the poor until you are equally poor. But more moderate utilitarians would say that, given a choice among reasonable options, you must simply choose the one that, as far as you can tell, benefits the most people to the greatest degree.

Well, we already established that cheating hurts your spouse—that would seem to make it wrong to a utilitarian, at least prima facie ("at first glance"). Compared to remaining faithful, cheating lessens your spouse's happiness or pleasure and increases her pain. Of course, your spouse may not be the only one affected—your children may also be hurt, either if they find out and are vicariously hurt through Mommy or Daddy being hurt, or even if they don't find out and and your spouse's pain nonetheless flows over to them. Family members, close friends, co-workers—anyone who is close to you may be affected, and utilitarianism demands that every person count equally when figuring the total good and bad caused by an action.

However, guess who else counts in that "everyone"? You. And therein lies one reason utilitarians might allow for cheating in some circumstances, particularly cases in which there is good reason to believe that you will benefit from the affair more than others will suffer. Let's say the romance in your marriage has completely disappeared; you and your spouse no longer speak, touch, or connect in any way. You begin to look elsewhere for the affection and intimacy you crave, whether sexual, romantic, or both. Maybe you don't think your spouse would even care—he doesn't want to be with you anymore, so why should he care if someone else does? It might lift you out of your misery to have someone in your life that cares, that wants you around, that you mean something to, and vice versa.

In such a case, and assuming that no one else (children, friends, etc.) would be significantly affected, a utilitarian would probably say "go ahead, do it!" Utilitarianism allows for some people to get hurt, as long as some other people are benefited by a greater amount (which is a frequent criticism of utilitarianism). Of course, you could be wrong about your spouse's feelings, or even about how much you stand to gain from an affair (maybe your guilt would overwhelm any positive feelings). But if to the best of your knowledge (and without rationalizing it to yourself), you believe that cheating on your spouse would increase your happiness more than it would lower your spouse's (and that of anyone connected to you), then the utilitarian would have to allow it.

To make matters more ambiguous, there is another person who stands to gain from the affair—your paramour. She's a person, and her well-being must be included in your pleasure/pain calculations. So that's another "positive" to add to your own, possibly able to offset the harm to your spouse (and others). If the person you plan to cheat with is in a similar situation to yours—you're both abjectly miserable in your separate relationships—that would make the case for cheating even stronger. But then again, what about your paramour's significant other? That's probably a negative... oh, my head hurts! There's a lot to consider when making utilitarian decisions, and that leads to the criticism that utilitarianism puts too much of a burden on decision-makers.

Some people justify their affairs by saying "it's for the good of the marriage," or "it will make our marriage stronger." In other words, I may be hurting my spouse now, but in the long run, we'll both be happier. While this may actually be a rationalization when people say it, it does have some philosophical validity. Utilitarians don't simply compare the pleasure and pain that an action causes right now, but also the effects it creates in the future. Utilitarians use this thinking to defend or criticize policies on such things as governmental budget deficits or environmental impact that will affect not only people presently living, but their children and grandchildren as well.

But one problem with this way of thinking is that it is very, very hard to predict the future. Economists disagree about the impact of budget deficits, scientists disagree about environmental effects, and reasonable people will disagree about the effects of infidelity on a marriage, even (or especially) if the people are in the situation themselves. How do you how your spouse is going to handle your infidelity? You may think you know him pretty well—he was your soul mate, at least for some time—but unless you did this to him before, you have no way to know how he's going to react. (And if you did do it to him, I think anyone can guess how he's going to react!) Once again, utilitarianism is very demanding regarding the information you need to make the best decision.

To conclude, utilitarians do make allowances for cheating in especially desperate cases, in which the consequences of cheating may be overall positive, but on the whole, they would agree that cheating is usually wrong. And we didn't even get into rule utilitarianism, which recommends rules that result in the right action most of the time. One example is "do not lie"—even though lies can occasionally do good overall, they usually don't, and following a rule of not lying will result in more good things than bad. The same thing would go for "do not cheat"—such a rule may prevent some "good" affairs, but it would prevent many more bad ones.

Answer 2: Because it involves breaking a vow or promise.

You might be saying to yourself (or to your computer), "cheating isn't wrong because it causes more harm than good—it's wrong because it means you're breaking your promise to be faithful, or violating your wedding vows." In other words, you would be saying that cheating is wrong regardless of the consequences, no matter if it makes you and your paramour happier than it makes others unhappy. If so, you may be a deontologist. (Congratulations—you've made your mother and me very proud.)

Deontology is somewhat hard to define, but often it's contrasted with ethical theories like utilitarianism, that base ethical judgment on outcomes or consequences. (Generally, such ethical theories are called consequentialist; utilitarianism is one type of consequentialism that focuses on utility as the consequence of choice.) Instead, deontologists make ethical decisions based on duties, rights, or principles that are not based on outcomes or consequences. For instance, a deontologist might regard lying as wrong because it violates a duty of truth-telling, or the right to be told the truth, or respect for other people, but not because it leads to bad outcomes.

A deontologist would be likely to say that cheating is wrong because it involves violating a duty of fidelity contained in the wedding vows, or breaking the promise you made to your spouse at your wedding, of failing to respect your spouse. A deontologist does not consider the good or bad consequences of any particular instance of cheating—cheating itself is wrong, because you should not break promises, violate your duty of fidelity, etc.

So cheating's wrong, period. That should do it for deontology, right? Not so fast. As we said before, few ethical systems endorse ironclad restrictions, even though deontologists (like Immanuel Kant) are often thought to. For instance, while deontologists may decide that cheating is wrong in general, they may make exceptions for certain circumstances, such cheating in the face of spousal neglect or abandonment. (I'm not saying that all deontologists would make these exceptions, but just that some may.) There are various ways to do this:

1. Some use the terms prima facie or pro tanto duties to describe duties that hold true in general, as long as there are no mitigating factors to speak against them. For instance, there is a prima facie duty not to kill, unless your own life is threatened. Likewise, cheating would normally be wrong, unless the person feels neglected by his spouse (for example). The mitigating factors may also include other duties that conflict with the duty of fidelity—for instance, the duty to look after your own emotional well-being.

2. Others would say cheating in general is wrong, but more elaborate descriptions of cheating, such as "cheating-when-neglected," would be OK. Again, think of killing in self-defense; while killing is generally wrong, killing-in-self-defense usually isn't, because the logic that forbids killing in general may not forbid killing in self-defense. In the same way, cheating may generally be wrong, but cheating-when-neglected may not be, depending on how the duties are formulated (for instance, by using the categorical imperative in Kant's ethics).

There's an importance distinction to make here: while many deontologists would allow exceptions to the general wrongness of cheating, they would be based on the circumstances surrounding the person cheating, not on the particular consequences of cheating. In other words, anyone in the circumstance of being neglected by her spouse may be justified in cheating, whether or not it leads to good overall consequences. On the other hand, even good consequences will not justify cheating if you don't fall under one of the circumstances that allow cheating.

In conclusion, deontology tells us pretty much the same thing that utilitarianism did: cheating is usually wrong, except in extreme cases. But while those cases are very hard to identify according to utilitarianism, which requires that you accurately predict the effects of your cheating on every relevant person, deontology makes its exceptions according to personal circumstances that are much easier to know. For instance, you know if you are neglected by your spouse, but you can only guess how cheating will affect you, your spouse, or anyone else.

Answer 3: Because it makes you a bad person

One more thing your friend may say when you tell her you're considering cheating is: "that's not the kind of person you are," or "what would you think of yourself if you did that?" Your friend would not be focusing on the consequences of cheating, or the morality of the act itself, but rather what cheating would say about you: your moral character, the person you think you are, and the person you aspire to be. And this is the domain of virtue ethics.

Virtue ethics focuses on those qualities of a person—the virtues, naturally—that make her a good person, or that contribute to leading a good life. As opposed to utilitarianism and deontology, virtue ethicists don't provide formulas or rules for determining which qualities count as virtues and which as vices; most of them are pretty common-sense. Honesty, obviously, is a virtue, as are kindness and trustworthiness. Fidelity would be another—we normally think of faithful people as good. Likewise, if you want to be a good person, and you think that fidelity is a virtue that contribute to a person being good, than you should aspire toward being faithful.

Well, that was even simpler than deontology, butdon't click to another post just yet—remember what we said about no ethical system being absolute? Virtue ethicists (especially those who draw their inspiration from Aristotle) also emphasize moderation in all things, especially when defining virtues. For instance, it is possible to be too honest, if you end up saying this that hurt people unnecessarily ("you know, Jim, you really are putting on weight"), or too kind, if you give away all of your money and end up needing financial help yourself. Virtues can be considered the "mean" between two extremes, which implies that any good quality can be taken to the extreme.

Likewise, fidelity can be taken too far. Imagine a woman in a broken marriage, whose husband neglects her and wantonly cheats on her, and who is miserable and maybe even suicidal. She knows a man at work who would be more than happy to take her out to lunch, get to know her better, maybe go to a movie (or more). It's not hard to imagine that a perfect devotion to the virtue of fidelity would be excessive in her case; it would not contribute to a good life in her case, and seeing her co-worker would hardly make her a bad person, especially given her circumstances (the same circumstances that would probably justify her behavior in deontological terms as well).


Is cheating wrong? We surveyed the three major ethical theories—utilitarianism, deontology, and virtue ethics—each of them essentially different, but all of them arriving at basically the same conclusion: cheating is usually wrong, but can be justified in certain, possibly rare, instances. The fact that all three of these moral systems agree makes for a pretty strong argument, and it would seem like a fairly common-sense one at that. Sure, some people may adhere to a strict code of "no cheating," no matter what, as typified by certain religious systems of ethics; and others will say "do whatever feels good," such as hedonists or ethical egoists. But these are the extreme ends of the spectrum (which itself is not an argument against them), and most people fall somewhere in the middle, as our description above endorses.

So if you're faced with a situation in which you, your spouse or partner, or someone else that you know is considering cheating (or is actually cheating), it is natural to condemn it out of hand. But remember that most moral philosophies allow for some justifications for cheating: some consider the consequences of the affair, others the circumstances around the affair, and yet others the character of the people involved. Whichever school of ethics sounds right to you, try to apply its lessons to your particular situation. If nothing else, it gives you one more way to look at things, and an additional viewpoint is always a good thing—no exceptions!

Other posts on adultery:

Suggestions for further reading

Utilitarianism is usually traced back to Jeremy Bentham (1738-1832) and his 1781 book The Principles of Morals and Legislation, and John Stuart Mill (1806-1873) and his 1863 book Utilitarianism. For prominent modern utilitarians, see Peter Singer and Richard Brandt.

The chief proponent of deontology is Immanuel Kant (1724-1804), whose seminal work in ethics is his 1785 book Grounding for the Metaphysics of Morals. Another prominent deontologist was W.D. Ross (1877-1971), whose most important work was his 1930 book The Right and the Good. Modern deontologists (chiefly Kantians) include Thomas E. Hill, Jr., Christine Korsgaard, and Marcia Baron.

For arguments between utilitarians and deontologists, see J.J.C. Smart and Bernard Williams' 1973 book Utilitarianism: For and Against and Samuel Scheffler's 1988 edited collection Consequentialism and Its Critics. Any ethics textbook or reader should also provide an excellent account of the contrast between these two important ethical theories.

Finally, virtue ethics goes back to the days of the ancient philosophers Plato (429-347 BCE), whose primary ethical work (written as dialogues) includes his Republic, and Aristotle (384-322 BCE), whose main ethical work is The Nicomachean Ethics (publication dates for the ancient works are unknown). Modern virtue ethicists include Philippa Foot, Michael Slote, and Julia Annas.

For some recent work specifically on adultery, along the lines of these three major ethical theories, you can look for these academic journal articles in your local college library:

  • Richard Wasserstrom, "Is Adultery Moral?", Philosophical Forum, vol. 5, pp. 513-528, Summer 1974.
  • Michael J. Wreen, "What's Really Wrong with Adultery," International Journal of Applied Philosophy, vol. 3, pp. 45-49, Fall 1986.
  • Mike W. Martin, "Adultery and Fidelity," Journal of Social Philosophy, vol. 25, no. 3, pp. 76-91, Winter 1994.
  • Raja Fouad Halwani, "Virtue Ethics and Adultery," Journal of Social Philosophy, vol. 29, no. 3, pp. 5-18, Winter 1998.