Is cheating wrong? At one point, there was a moral consensus on this question across political and cultural lines. But now, many on the left seem to have reconsidered the immorality of adultery.

The Ashley Madison hack has spurred a national debate on data privacy as well as the state of marriage in society. Pundits like Fredrik deBoer, Dan Savage, and Glenn Greenwald wasted no time commenting on the controversy by pushing several familiar narratives:

1. Adultery is a victimless and harmless act and therefore within the bounds of morality. If two (or more) people consent to sexual activity, that is their prerogative, and society must be accepting of that choice or at the very least respectful and understanding.

2. The fact that many conservative people do not accept adultery is a function of their religious prudery. That is the only reason anyone could possibly have for opposing consensual sex, which, in the final analysis, is a private matter that ought to remain beyond the scrutiny of others.

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3. By insisting that adultery is immoral, religious groups are imposing their puritanical beliefs on others, stigmatizing the innocent lifestyles of certain people, and dehumanizing those who engage in otherwise harmless intimate relationships in pursuit of love and happiness.

We know these arguments so well because they are endlessly rehashed to defend the morality of homosexual acts and the push to redefine marriage. Simply replace every instance of the word “adultery” in the above with “homosexual act” or “same-sex relationships” and the parallels become undeniable.

What is interesting is that, unlike homosexuality, infidelity has not been embraced by our culture. According to a 2013 Gallup poll, 91 percent of respondents believed that married men and women having an affair is morally wrong. According to another study, even a large proportion of married individuals who cheated believed that their actions were immoral. Apparently, while the stigma associated with other sexual behaviors—like premarital, gay, and lesbian sex—has waned over the past decades, the social taboo against extramarital sex is alive and well.

Clearly, the liberal argument for the morality of adultery has not convinced the majority of Americans. This is instructive because liberalism often attributes society’s changing attitudes toward sexual morality as the public increasingly seeing “the light of reason” and the triumph of secular rationality over traditional religious closed-mindedness. Against this narrative, however, the public’s reluctance to embrace adultery despite liberalism’s standard set of arguments demonstrates how much of the liberal argumentation against traditional sexual mores hinge on cultural sympathy as opposed to sound reasoning.

Sympathy and the Harm Principle

We can see exactly how cultural bias factors into liberal argumentation by considering the core concepts upon which many of the arguments rely. Chief among these is the notion of harm. Most liberal ethical formulations draw heavily on John Stuart Mill’s philosophical elaboration of the “Harm Principle” in On Liberty. Many contemporary Americans believe that only acts that hurt other people should be the object of moral opprobrium. But as legal scholar Stephen D. Smith explains in The Disenchantment of Secular Discourse, from a purely secular perspective, harm is a subjective and context-dependent concept. Without the moorings of a normative doctrine like religion, the liberal secular treatment of harm can vary greatly.

The fact that some commentators are questioning whether adultery is harmful is a glaring example of how malleable and culturally dependent the liberal conception of harm truly is. In his piece, deBoer asks defiantly, “Suppose  . . .  all of the exposed Ashley Madison users were just cheating. So what? Why should that be the concern of progressive people?” He further muses, “We’ve collapsed the distinction between behaviors that are truly destructive and must be illegal, like sexual assault or sexual coercion, and those that we merely find untoward, like cheating.” From this perspective, infidelity is—at most—rude and unseemly, akin to picking one’s nose in public or not washing one’s hands after using the restroom.

What this means is that a spouse who is cheated on is not really a victim and has no legitimate grievance against the cheater and his lover. After all, why should something as silly as marriage vows hinder a person’s sexual autonomy? Whoever is foolish enough to take the bonds of matrimony seriously almost deserves to be cheated on. It’s “just cheating,” after all! Let’s try to be mature about it and learn to “mind our own business,” as deBoer casually puts it. The implication is that the 91 percent of the public that believes infidelity is a serious moral violation is nothing more than a bunch of prudes infected with a puritanical or Victorian self-righteousness.

We might wonder, why couldn’t the pain and suffering that the betrayed spouse feels—which some psychologists speak about in terms of post-traumatic stress disorder—be considered harmful in the logic of secular liberalism? One would think that, given how much stock liberal ethical theory puts into sexual autonomy and the negative emotional and psychological impact of curtailing sexual freedom, liberal pundits would express at least some passing consideration for the negative emotional and psychological impact of adultery upon the betrayed spouse.

The difference, we are told, is that the emotional distress of the betrayed spouse is due to a misplaced sense of marital commitment, which is ultimately based on provincial religious attitudes, whereas emotional distress caused by curtailed sexual freedom is based on immutable human needs at the core of personhood. In other words, if a married man has sexual needs that can only be satisfied by someone not his wife, those needs take priority over marriage vows. To put the point succinctly: sexual needs are real, but marriage vows are based on religion, which is not real as far as rational secularism is concerned. If betrayed spouses feel bad, it is their own fault for naively buying into this whole idea of marital commitment. This is similar to the way in which parents and family members who are distressed when a loved one adopts a “gay lifestyle” or chooses to have sex-change surgery are told that their distress is not legitimate. Rather, any negative emotions or harm are their own fault—the result of buying into naive and prudish views on sexuality and gender.

Other Victims

Arguments in this vein conveniently render adultery a harmless, victimless act. But what about other factors that could be seen as harmful? For example, there are empirical data to suggest that parents’ unfaithfulness often negatively affects children. Family instability, often the result of adultery, correlates with numerous social ills, such as drug use and depression among adolescents, dropping out of school, and future unemployment. Do these harms outweigh the purported benefits of cheating? Even under a purely utilitarian conception of sexual morality, it would seem the harm from such social problems is more significant than the harm that may come to a person who has to withhold himself from cheating.

In other contexts, liberal commentators are eager to highlight these same social ills. Consider the bestselling book Freakonomics. The authors present research that correlates the legalization of abortion with subsequent drops in crime rates. They hypothesize that legalizing abortion made it easier for women to terminate unwanted pregnancies, which caused a decrease in unwanted births and meant that fewer children grew up in detrimental environments and unstable households that would make them prone to criminality.

Pro-abortion advocates often use these sociological data on crime rates to argue that abortion greatly benefits society as a whole. The obvious conclusion that goes unnoticed is that these same benefits of abortion could be equally achieved by preventing premarital and extramarital sex. The exact same logic applies—if fewer people have sex outside of marriage, fewer children will be born to mothers who are not in a position to provide an upbringing that will prevent those children from eventually falling into illegal and destructive behavior. Research shows that crime rates, education levels, unemployment, drug use, and future income all can be significantly influenced by controlling reproduction via access to abortion and contraception. Obviously, those same benefits would, mutatis mutandis, be obtained by a decrease in the amount of premarital and extramarital activity.

What would liberalism say about all of this? As we saw, liberal ethics can explain away the pain of a betrayed spouse by arguing that that pain is based on religious beliefs. Since religion cannot be taken seriously in secular moral considerations, those beliefs are just “hang-ups” that the betrayed spouse should dispense with. Similarly, the liberal ethical perspective could maintain that if children are distressed by their parents’ infidelity and the subsequent instability in their home life, that distress is also the result of misbegotten expectations. Children ought to be taught that it’s okay for Daddy and Mommy to have affairs. In other words, if everyone’s expectations are properly set in accordance with postmodern liberal conceptions of family and sexuality, then no harm will arise.

The Hypocrisy of Liberal Sexual Ethics

There are several problems with this reasoning. First, it is question-begging. Obviously, if everyone believed that this highly individualistic liberal model for society were correct, these harms would go away. But if everyone believed that the traditional religious attitude about sexual freedom and propriety were correct, then no married person would ever feel frustrated or sexually deprived by not being able to cheat on his spouse.

The second problem is that there are still plenty of other grave harms associated with adultery that have nothing to do with expectation-setting. For example, what about the right of a husband to know that the children his wife gives birth to are his children and not the children of other men? Given the significant amount of financial resources needed to raise children, this is not a trivial concern. Or how about the right of a wife to know that her husband does not have illegitimate children that he is supporting behind her back, in essence secretly siphoning off funds from their family to support children from another woman? How about a child’s right to know who his biological parents are, and the right not to feel like one’s birth was the result of a mistake or a sleazy affair?

These are all rights that other cultures consider to be basic human rights. In Islam, for example, these rights are enumerated in great detail in traditional manuals of Islamic law and are considered to be among the cardinal reasons for God’s prohibition of adultery. Christianity and other religious traditions also recognize these rights and concomitant harms. Up until the nineteenth century, American courts noted that, “The harm of adultery lay not in the alienation of the wife’s affections and loss of comfort in her company but in its tendency to adulterate the issue of an innocent husband and to turn the inheritance away from his own blood, to that of a stranger.”

Given these harms, wouldn’t proper application of the “Harm Principle” lead us to conclude that infidelity is indubitably immoral? The fact that these considerations are so often overshadowed by an obsessive, dogmatic concern for “sexual freedom” is proof of the one-dimensionality and inherent hypocrisy of liberal sexual ethics. If liberalism can be so clumsy, out of touch, and misguided when it comes to a moral issue as clear-cut as adultery, what does that say about liberalism’s treatment of other points of sexual morality?