1 Introduction

Imagine that two partners are in a romantic relationship, and that they are also (or perhaps a fortiori) friends. Yet theirs is not a typical relationship, for the partners have agreed on a most unusual restriction: Neither is allowed to have additional friends. Should either partner become friends with someone besides the other, the other partner will refuse to support it—indeed, will go so far as to withdraw her love, affection, and willingness to continue the relationship.

Many of us, I think, would sense that there’s something morally troubling about such a relationship. If asked to explain what’s morally troubling about it, we might say something like this: Friendships are an important human good, and when we’re in a romantic relationship with someone, we should want our partner to have such goods in her life. Or at least, we should want our partner to be free to pursue such goods as she sees fit. And part of letting our partner have the freedom to pursue her own good is to refrain from imposing costs on her when she does so. In the case of friendship, then, we shouldn’t impose costs on our partner—for example, by withdrawing our love, affection, or willingness to continue the relationship—if he becomes friends with someone else. Indeed, many would say that we should go further and actively support our partner’s efforts to find other friends. When our partner becomes friends with someone else, we should be happy for her—for she now has an additional source of value in her life.

So far, so good. But now consider this: Sexual and romantic relationships are themselves an important human good. They, too, contribute to our well-being in myriad ways—whether through sexual pleasure, through a special kind of emotional support and closeness, through helping us to discover more about ourselves, or through the countless other everyday joys of sharing one’s life intimately with another. So why not simply be happy for our partner if he found an additional partner, much as we’d be happy for our partner if he found an additional friend? Is disallowing one’s partner from having additional partners any better than disallowing one’s partner from having additional friends?

Questions like these are rarely asked, and even less often taken seriously. Most of us assume that there’s nothing morally suspect about having one’s relationship be dyadic and exclusive—that is, involving exactly two partners, and permitting neither partner to engage in romantic or sexual activity with anyone outside the relationship. We tend to assume, in other words, that monogamy is morally permissible—that there must be some morally relevant difference between disallowing one’s partner from having additional partners and disallowing one’s partner from having additional friends. Yet finding a morally relevant difference between the two is much more difficult than it might seem, for, as I’ll now argue, the standard defenses or justifications of monogamy all fail. I take this failure to be evidence that the “no additional partners” restriction of monogamy is in fact morally analogous to the “no additional friends” restriction described earlier. Just as a categorical restriction on having additional friends is immoral, so, too, is monogamy’s categorical restriction on having additional partners.

2 Monogamy on the Defensive

We’ve seen above how monogamous restrictions are prima facie analogous to a morally troubling “no additional friends” restriction. The task for those who would defend monogamy, then, is to find a morally relevant difference between the two kinds of restriction. There are broadly two ways in which one might try to find such a morally relevant difference: (1) argue that the “no additional friends” restriction has bad-making features that monogamous restrictions lack, or (2) argue that monogamous restrictions have good-making features that the “no additional friends” restriction lacks.

It is easy enough to imagine how one might go about the first of these strategies. One might say, for example, that a restriction on having additional friends would be much more onerous than monogamous restrictions. After all, to refrain from having additional partners merely requires that we keep our romantic and sexual activity to one person at a time, and surely that’s not so hard or extraordinary. But to refrain from having additional friends would require a much more sweeping change to our social life. Were we to restrict ourselves from having additional friends, we’d have to make sure not to be too friendly to others we know, not to laugh or chat too much with them, not to invite them to spend time with us, not to accept their invitations to spend time with them, not to go out of our way to support them when they’re in need, not to accept their support when we’re in need—in short, we’d have to make sure that our relations to all others (save our partner) stay businesslike at best. Such a straightjacketed social life is something no minimally decent person would want for her partner.

I grant that a restriction on having additional friends would be a good deal more onerous than monogamous restrictions, and that this is, in some sense, a morally relevant difference between the two kinds of restriction. Yet it is a morally relevant difference only in a weak sense, namely that it suggests that the restriction on having additional friends is morally worse than monogamous restrictions. And this, of course, is not what the defender of monogamy needs— since however worse the restriction on having additional friends is, it could, for all we know, be that monogamous restrictions are still morally impermissible. Some morally impermissible actions, after all, are worse than others; ceteris paribus, it’s morally worse to assault someone than to tell him a lie, yet that hardly suggests that lying is morally permissible.

What the defender of monogamy needs, then, is not simply to show that monogamous restrictions are morally better than the restriction on having additional friends, but that monogamous restrictions are morally permissible. And to do that, the defender of monogamy will have to go beyond strategy (1) above; that is, she’ll have to go beyond simply arguing that the restriction on having additional friends has bad-making features that monogamous restrictions lack. After all, however many unique bad-making features the restriction on additional friends might have, what matters is whether there is even one bad-making feature that it shares with monogamous restrictions. I’ve suggested above that there is a bad-making feature they share: Both restrict one’s partner’s access to a prima facie important human good—in one case, (additional) friendships, in the other, (additional) sexual and romantic relationships.

At this point, the defender of monogamy might say that while both kinds of restriction have this apparently bad-making feature, this is a problem only for the restriction on having additional friends—for only this latter restriction seems to lack any justification. There’s simply no good reason why partners should restrict one another from having additional friends. When it comes to sexual and romantic relationships, however, there are good reasons why partners should restrict one another from having more than one at a time. Here the defender of monogamy is opting for strategy (2) above—that is, arguing that monogamous restrictions have good-making features that the restriction on additional friends lacks. This is a more promising route than strategy (1), for, to the extent that monogamy has unique good-making features, that could explain why monogamy is morally permissible while the restriction on having additional friends is not. Let’s consider, then, some attempts to find unique good-making features of monogamy—in short, some defenses of monogamy.

Here, regrettably, I cannot consider all the defenses of monogamy on offer. In particular, I must set aside some of the more sophisticated and recherché defenses in favor of those that are simpler, better known, and more likely to resonate with monogamists in general. Given the very limited state of the literature on the topic, even these latter kinds of defenses of monogamy have not yet received much critical attention. In addressing them here, I hope to show that defending monogamy turns out not to be nearly as easy as most people assume.

2.1 The Specialness Defense

One common defense of monogamy is that monogamy helps one’s romantic relationships to be special. Many think that there is or can be a distinctive value in choosing, and being chosen by, just one person. This distinctive value, the thought continues, is enough to justify monogamy.

The most obvious problem with this defense of monogamy is that it seems to apply equally to the case of friendship. If having only one partner makes for a more special romantic relationship, and if the value of this specialness is sufficient to justify monogamous restrictions, then it is difficult to see why having only one friend would not likewise make for a more special friendship, and why this specialness would not likewise justify the “no additional friends” restriction described earlier. But clearly such an appeal to specialness could not justify the “no additional friends” restriction. Having additional friends does not make any particular friendship less special. And the same holds true for affectionate or loving relationships more broadly. Consider, for example, the relationship between parents and children. We do not generally think that having strictly one child is a way of making the parent-child relationship more special; were one to have more children, would not one’s relationship with the first child remain just as special? And would not one’s relationships with the other children be just as special as one’s relationship with the first child? If indeed that is so, then those who defend monogamy on grounds of specialness must point out a relevant difference between romantic relationships and other loving relationships—some difference in virtue of which one could have a more special romantic relationship by having only one partner yet not have, say, a more special parent-child relationship by having only one child. It is far from clear whether there is such a difference, much less what it might be.

I can think of only one reason why one might think that monogamy helps one’s relationships to be special: if one understands “special” to mean “exclusive.” (This sense of “special” occurs in sentences like “There will be special seating for us at the event.”) Under this understanding of “special,” monogamy indeed helps one’s relationships to be special; that, of course, follows trivially from equating “special” with “exclusive.” But surely there is more to this defense of monogamy than the trivially true claim that monogamous relationships are more exclusive than nonmonogamous relationships. We must, then, find another understanding of “special.”

I propose that we understand “special” here to mean “highly valuable.” This, I think, is a much more natural sense of the word to use when talking about loving relationships (e.g., “My relationship with this close friend is very special”). If monogamy helped relationships to be more special in this sense, that would certainly be a point in its favor. Notably, however, it does not follow from the fact that monogamy makes a relationship more special in the first sense, the sense of exclusivity, that it makes a relationship more special in the second sense, the sense of being highly valuable. Or at least, if it does follow, it is not at all obvious. Especially in light of the other examples of loving relationships, such as parent-child relationships, I cannot come up with any good reason to think that exclusivity somehow helps a relationship to be highly valuable. What seems more likely is that it is only if one conflates the above two senses of “special” that this defense of monogamy will seem plausible.

2.2 The Sexual Health Defense

A further defense of monogamy centers on sexual health. The idea is that having multiple sexual relationships at a time leads to a much higher risk of sexually transmitted infections (STIs) and, in heterosexual relationships, of unwanted pregnancy. If partners want to reduce such risks, they are well advised to restrict each other to one sexual relationship at a time—in other words, to embrace monogamy.

Sexual health is an important concern. For multiple reasons, however, it fails to justify monogamy. First, a concern for sexual health is simply too narrow to justify the full range of monogamous restrictions. After all, monogamous restrictions apply not only to sex, but to activities like intimate dancing and outercourse, and often to emotional intimacy as well. Even if the sexual health defense succeeds in justifying monogamous restrictions on sex, it does little to justify these other restrictions that are a part of monogamy.

More damningly, the sexual health defense does not even succeed in justifying monogamous restrictions on sex—not in light of the various methods of contraception and safer sex. Through properly using condoms and other methods of safer sex, partners can dramatically reduce the risk of STIs and unwanted pregnancy. Some might object that even with such methods, the risk is not wholly eliminated. But then, there are risks of all kinds to be found in activities that we nevertheless find worthwhile. Driving, biking, and playing sports, for example, all involve risks, particularly risks of bodily harm or even death. Yet it would be silly to say, merely on that basis, that we ought not to engage in such activities, or that it is okay for partners to forbid one another from engaging in them. I see no reason for thinking that non-monogamous sex is any different.

A genuine, intellectually honest assessment of risk must take into account not only the fact that a risk exists, but the nature and extent of the risk weighed against the benefits of the activity that carries the risk. In order to justify monogamy on grounds of sexual health, one would have to show that the risk of STIs and unwanted pregnancy is so serious, and the benefits of non-monogamous sexual activity so minor, that it makes sense for partners to refuse one another even the possibility of taking on board a new sexual relationship. To be sure, some cases may well fit this description, especially in areas where protection, contraception, and STI testing are unavailable. However, for those of us in developed countries with access to contraception, protection, and STI testing, considerations of sexual health alone are not likely to justify monogamy.

Risk assessments ought generally to be done case by case, with open discussion between partners. Admittedly, even for those who do have access to sexual health resources, in some cases sex with another may not be worth the risks involved. For example, suppose that a certain person refuses to discuss his sexual history, get tested, or use protection. In such a case, clearly each partner in a couple would be right to bar one another from sex with that person. Acknowledging the potential for cases like this, however, does nothing to justify the across-the-board restrictions inherent to monogamy, for there are other cases in which the risks are much lower (say, when a new potential partner is perfectly willing to discuss his sexual history, get tested, and use protection). Embracing non-monogamy, it is essential to remember, does not at all mean that one must be open to any sexual contact between one’s partner(s) and others. Rather, it means that one will, at least in principle, be open to sexual contact between one’s partner(s) and others in at least some cases. More precisely, if one is to be consistent in one’s non-monogamy, one should be open to sexual contact between one’s partner(s) and others in any case in which there is no good reason not to be open to it.

2.3 The Children Defense

The next defense of monogamy centers on raising children. Specifically, one might think that monogamy is the healthiest relationship style for raising children; children develop best when they see their parents as romantically involved only with one another. Of course, this point could justify monogamy only for partners who have children, particularly young children; it does nothing to justify monogamy for partners who are child-free or whose children have grown up. Still, many partners do in fact have young children. So if indeed in those cases monogamy is justified, that’s a strong point in monogamy’s defense.

There are multiple problems with this defense of monogamy. The first is that, even if we assume that it is harmful to children to see their parents be romantically involved with others, it does not follow that parents ought not to be romantically involved with others. To draw an analogy, we might suppose that watching violent films is harmful for young children. It does not follow, of course, that parents ought not to watch violent films. They need only make sure that, if they decide to watch violent films, they do so when their children are away or asleep. Similarly, even if young children need to see their parents as monogamous, parents are nevertheless free to have other relationships; they need only keep their other relationships private. Perhaps this will strike some as wrongfully hiding the truth from children. Yet that objection seems odd; since when are parents not allowed to have a private life? Moreover, as a matter of course, parents refrain from exposing their children to things that the children are considered too young to confront or understand—not the least of which happen to be the parents’ own sexual relations. Why would the parents’ sexual relations with others be any less okay to keep private?

Thus far in my response I have assumed that children develop best when they perceive their parents as monogamous. As it turns out, there is no good evidence for this assumption; it is mere speculation, with about as much plausibility as the speculation that children develop best with heterosexual parents. By the evidence available, whether a family environment is monogamous or non-monogamous does not by itself have any bearing on how suitable it is for children. Apart from having basic, material needs met, what matters most for children is having an ample amount of love, support, acceptance, and understanding. There is no reason to suppose that parents must be monogamous for their children to have the love, support, acceptance, and understanding that every child needs. If anything, for parents to have other partners who help provide these needs is likely to be helpful, not harmful, to the children.

Still, some might feel a lingering worry. One feature of non-monogamous relationships, after all, is that partners break up. A pair of non-monogamous parents will often have a gradual stream of partners coming into and out of their lives over the years. If the children get to know and to spend time with these partners, the children are prone to becoming attached. Thus, when either parent breaks up with a partner, does that not present a hardship for the children? Won’t the children feel hurt and abandoned?

It is indeed true that non-monogamous parents sometimes break up with their partners—including partners who have become a valued part of the children’s lives. In not at all such cases, however, will this present a hardship for the children; particularly when the breakup is amicable, the ex-partner might well remain friends with the parents and thus continue to have a place in the children’s lives. Of course, in cases where the ex-partner does depart from the children’s lives, whether for having broken up with the parents on bad terms or for any other reason, that is indeed saddening for the children. Ultimately, though, such a prospect is not a good reason for parents to stick to monogamy. After all, there are all kinds of figures who give invaluable support and guidance to children, and to whom the children become attached, yet who have only a passing presence in the children’s lives. As children grow older, they must say goodbye to valued teachers, coaches, camp counselors, grandparents, pets, and friends. I doubt anyone would suggest that it would be better in the end if such figures were never an important part of children’s lives in the first place, just so the children could be spared the pain of seeing them go. Even with the pain of saying farewell, the children are better off for having known them. But then, why would the same not hold true in cases where non-monogamous parents cut ties with one of their partners?

A further point is that the above worry—the worry about how children might be affected by breakups between parents and their partners—applies not only to nonmonogamous parents, but also to monogamous single parents. A monogamous single parent might well have a series of partners gradually coming into and out of her life as her children grow up. Is the risk of the children’s being harmed by breakups so grave that monogamous single parents ought not to start new relationships? Surely few would want to say this.

There is only one further way I see of defending monogamy by appealing to the need to protect children, and that is to charge that non-monogamy is too impractical for raising children: Parents simply do not have enough time or energy to devote themselves adequately both to their children and to (multiple) other partners. But that leads us to the next defense of monogamy, a defense that deserves a section of its own.

2.4 The Practicality Defense

One might defend monogamy on practical grounds. One might argue, for instance, that while it would be nice if we could devote our romantic attention to unlimited partners at a time, our time and energy are finite. Being monogamous, then, is a way for us to ensure that we do not, by taking on too many partners at a time, become unable to devote the time and energy to our partner—and, if we have them, our children—that are called for in a relationship.

There’s no doubt that we humans are limited in our time and energy. Yet this does nothing to justify monogamous restrictions. The mere fact that we are incapable of devoting our romantic attention to unlimited partners at a time hardly justifies setting the limit to one. After all, we are likewise incapable of having unlimited friends at a time, but surely that doesn’t justify a “no additional friends” restriction like the one described in the introduction.

Another problem with the practicality defense is that it could be directed at any use of time and energy that does not involve one’s partner or children. Should one pursue a hobby or spend time with one’s friends, then—barring the prospect of having one’s partner and children along for everything one does—one will be spending time and energy away from one’s partner and children. Surely there is nothing wrong with this. Indeed, it is a normal part of healthy relationships. But in light of this, the practicality defense is in trouble. Since it is acceptable for one to spend time and energy away from one’s partner and children, why should it matter if some of the time and energy one spends away from one’s partner and children happen to involve sex and romance with others? From the standpoint of time and energy management, at least, there seems to be nothing wrong here.

There is, however, an improved version of the practicality defense. Specifically, one might propose that not merely time and energy management, but considerations of people’s emotional limitations can justify monogamy. Romantic relationships, after all, require us to extend our concern to others, to be wrapped up in their world, to become vulnerable to them. And, no matter how much we may wish it were otherwise, we can love and care for other people only so much. Given the emotionally demanding nature of romantic relationships, along with our own emotional limitations, it is entirely legitimate to focus our attention on developing one relationship at a time—and to expect our partner to do the same. In at least some cases, partners who commit to directing their attention in this way will have a deeper, more manageable, and more satisfying romantic life than they would if they spread themselves more thinly.

While more plausible than what came before, this new version of the practicality defense has its own set of problems. The first stems from the fact that not all forms of non-monogamy involve openness to multiple emotionally intimate relationships at a time. In some forms of non-monogamy, the focus is on sex rather than emotional intimacy. Even if we grant that a single romantic relationship will leave us emotionally exhausted, allowing casual sex on the side (but nothing beyond that) seems just as much a solution as opting for full-blown monogamy.

But surely this won’t do, some will object—for what starts as a bit of casual sex on the side can all too easily become something more serious. If we wish for security and stability in our romantic relationships, then, we must stick to monogamy. This maneuver, I must say, strikes me as tenuous. Surely much of the time, we can reasonably be confident that the potential for a close emotional bond with another is low, and that the connection is purely or primarily sexual. Nevertheless, we can set that issue aside. For there lurks a deeper problem here. To see what it is, let us imagine a case in which a casual sexual relationship does morph into something more serious. It begins with two acquaintances who decide to indulge in the occasional hookup. At this stage, their connection will not be emotionally draining, since it lacks an emotional bond altogether. Now imagine, though, that over time their connection comes to hold a deeper emotional significance. The two come to have not just a sexual acquaintanceship, but a sexual friendship. Surely this new stage of their connection need not be emotionally burdensome—not more than any other friendship, anyway. Now imagine, lastly, that their sexual friendship becomes more serious still—indeed, that it becomes a close friendship. Must it now be emotionally burdensome?

No again, it seems. After all, close friendship is not something we in general find emotionally taxing—more truly the opposite, in fact. Rather, in our close friendships we find a source of love, support, and empathy. And even when close friendships do contain challenges, such as moments of stress or tension, these do not tend to be dominant or definitive features of the friendship; they are the exception rather than the rule. On the whole, our close friendships energize, encourage, and empower us. And their doing so does not appear at all contingent on whether they happen to involve sex. Thus, we may conclude that the above partners’ connection in its final stage need not be emotionally draining. And now for the crucial point: Their connection in its final stage just is a romantic relationship. In having a sexual relationship that is equally a friendship—and not just a friendship, but a close friendship— the partners hold a deep bond both physically and emotionally. It is precisely this kind of bond that is a hallmark of romantic relationships. The result we face, then, is that romantic relationships need not be so emotionally burdensome after all.

Why might it seem to so many that romantic relationships, by their very nature, leave us emotionally exhausted? One thing that might explain the popularity of this thought is the common assumption that one’s partner is supposed to meet all of one’s deepest personal needs, such as love, sex, and companionship. In holding this assumption, partners subject themselves to a more stringent standard of behavior in their relationships. Any failure of either partner to meet the other’s personal needs will present itself as a grinding obstacle that must be set straight, should it be possible, in order to have a proper relationship. To live under such a standard can no doubt be tiring.

The assumption that one’s partner is supposed to meet all of one’s personal needs, however, is itself a relic of monogamy. If one is allowed to have no more than one partner at a time, then it is easy to see why one’s partner would be expected to meet all of one’s personal needs. When no one else is allowed to provide sex or romantic love, failures of one’s partner to meet these needs will, barring cheating, mean that these needs will go unmet. But absent a background of monogamy, the assumption that one’s partner is supposed to meet all of one’s personal needs collapses. If one is allowed to have multiple partners at a time, after all, then failures of a certain partner to meet some of one’s personal needs do not have to be grinding obstacles in the way of a satisfying romantic life. For one can simply have those needs be met by another partner. For example, for some partners the focus can be on fulfilling sexual needs, while for other partners the focus can be on emotional needs.

While such arrangements might at first seem strange, a similar pattern holds in friendship: We do not expect a friend to be everything, to provide everything, to meet all of our personal needs. (Indeed, imagine that one did hold such an expectation of a friend—would we not find this neurotic and absurd?) Some friends are valuable to us in some ways, while other friends are valuable to us in other ways. Why should it not be the same with our partners in romance?

2.5 The Jealousy Defense

I arrive now at what appears to be the most popular defense of monogamy, the defense that comes almost immediately to everyone’s mind: the appeal to jealousy. In jealousy our thoughts and feelings flail about within a mire of crippling anxiety, despair, self-loathing, sometimes even rage. And it all seems to come from seeing our partner take an interest in someone else. What option is left to us partners, then, but a mutual promise to forsake all others? At stake here is our comfort, our happiness, our sanity. Only monogamy can keep us safe from jealousy; that is its justification.

In the face of the sheer power of jealousy, it’s easy to lose sight of the question of why we feel jealous. Yet that is a question worth posing here at the outset, for jealousy, when we pause to reflect on it, truly is odd. After all, when we see our partner find joy in someone else, would it not make more sense for us to be happy for her? Would it not be truer to our love, truer to our good will, to share in her joy? Surely delight and encouragement are the right, the sensible, the mature—truly, one might say the loving—reaction to our partner’s good. Why, then, when our partner’s good happens to involve an interest in someone else, do we feel so awful instead?

The answer, I think, can only be that we feel jealous precisely because we are less rational and less mature than we could be. Were it not for certain unreasonable fears and preconceptions that burden our minds, we would react to our partner’s new love in the way that is so evidently called for: by simply being happy for him. Which fears, which preconceptions keep us from this? First and foremost here is the fear of losing our partner to someone else. When we feel dread at the prospect of our partner’s finding a new lover, what most often underlies our feelings is the worry that our partner will come to desire her not in addition to us, but instead of us. Second, what breeds jealousy further is the common assumption that if our partner wishes for another or finds happiness in another, this means that there’s something wrong with us and our relationship—in short, that we’re “not enough” for our partner.13 When we see any indication of interest in someone else as a sign that our partner is dissatisfied with us, it’s only natural for us to feel hurt at the sight of our partner taking interest in another. Although other factors can play a role in jealousy, it is these two—the fear of losing our partner to someone else, along with the assumption that for our partner to show interest in someone else is a gesture of dissatisfaction with us—that appear to lie most insidiously at its root.

Now that we have in mind these key factors behind jealousy, we are in a better position to consider whether monogamy is the solution. Many people take it as obvious that monogamy is the only answer, or at any rate the best answer, to jealousy. In fact, however, this is far from obvious. As is well known, monogamy does not preclude jealousy; indeed, it is a commonplace in monogamous relationships to worry whether one’s partner is interested in someone else, or even simply whether she might become interested in someone else. Why is this? Wasn’t monogamy supposed to ensure freedom from jealousy? As it turns out, it’s no surprise that monogamy fails to preclude jealousy. For monogamy is not a way of addressing the factors, described above, that underlie jealousy; instead, it is merely a capitulation to them.

I use “capitulation” quite intentionally here. What I mean by it is that, rather than confronting the underlying needs or problems that jealousy indicates, monogamy is instead simply a way of avoiding behaviors that trigger jealous feelings, even at the cost of restricting the partners’ freedom and well-being. To see in more detail what I mean, let’s consider an example from another context. Imagine that two partners are beset by jealousy not of the romantic or sexual kind, but jealousy of a kind that centers on one another’s accomplishments in the workplace. Each fears seeing his own work become outmatched by that of his partner. This fear, in turn, feeds on the partners’ shared assumption that if one’s partner is producing superior work, that shows one’s own work to be inadequate. In the face of their jealousy, the partners mutually commit to putting out only mediocre work from now on; that way, neither will feel jealous of the other’s accomplishments.

Now let us ask ourselves whether the partners have chosen a healthy, desirable solution to their jealousy. Clearly not—and not simply because the doubts and disquiets of jealousy remain likely to lurk in the partners’ minds. (“Oh dear—what if he gets careless on his current project and ends up producing something good?”) More deeply, what is wrong is the very spirit, the very direction of the partners’ whole approach to the matter. Rather than running away from their jealous feelings, as it were, by restricting their behavior so as not to trigger them, the partners should confront their jealous feelings head-on. They should take responsibility for their feelings, seek to overcome their insecurities, work to free themselves from the fears and false assumptions that give rise to the problem in the first place. They should, in short, take the path of greater maturity.

I’d now like to suggest that monogamy is analogous to the above case. Monogamy, too, is a capitulation to jealousy. Just as with workplace jealousy, the proper response to romantic and sexual jealousy is not to restrict our behavior in order to avoid triggering it, but instead to confront it head-on. Below I’ll say more about how we can do so. First, though, we should take a moment to recognize just how counterproductive monogamy’s capitulation to jealousy really is.

Not only does monogamy fail to be a guarantee against jealousy. Worse, by capitulating to jealousy, monogamy in fact perpetuates it. To see how, consider the opportunity costs that are a part of monogamy. If you are in a monogamous relationship, your partner has committed not to be with anyone else. By this simple fact, monogamy makes it much more natural to worry about keeping your partner. For in being with you, your partner is forgoing other options, and the only way for him to openly pursue those options is to end his relationship with you. From here seeps the unshakable awareness: “The more desirable those other options seem, the more desirable it will seem to my partner to leave me for someone else.” It’s this kind of relationship style that breeds jealousy so well, that stokes the fear that your partner will decide to “trade up.” Under monogamy, it’s all too natural to be concerned not simply that your partner likes you, but that he does not like anyone else more.

Together with this heightened fear comes a sense of pressure: pressure to be more impressive than the others, to ensure that you always one-up the “competition” for your partner. (How sad it is that monogamy makes the word competition come so naturally here, when talking about something like the love of your partner!) And a trying task this often is. As noted earlier, monogamy fosters an expectation that you’re to fulfill all of your partner’s personal needs; after all, it’s not as if she is allowed to reach out to other partners here. Naturally, facing such a high standard only makes it easier to feel insecure, to worry whether you’re really enough for your partner. In every mistake, every shortcoming lies an invitation to wonder, “Might this just have led my partner to think, even if only for a moment, that it’d be nicer if someone else took my place?” All of this builds up a perfect environment for jealousy to fester.

As these considerations suggest, monogamy is not the solution to jealousy; indeed, it is largely what makes jealousy so persistent a problem in the first place. The kind of context in which jealousy most readily stews is that of a refusal to share, that of competition for something—precisely the kind of context sustained by monogamy. By abandoning monogamy, we destroy much of the lifeblood of jealousy. Accordingly, it is with the abandonment of monogamy that the real solution to jealousy begins.

But abandoning monogamy is only the first step. Other steps remain. Rather than capitulating to jealousy in the vain hope that that will make it go away, as monogamy does, these further steps involve confronting jealousy directly. That is how we can best be assured of being free of jealousy in the end—or, at the very least, assured that whenever jealousy does arise, we will have healthy, effective ways of coping with it and working through it.

Here, more specifically, are some of the key steps by which we can confront jealousy directly. The first is simply to realize how irrational jealousy is. Jealousy is built on a bed of unreasonable fears and false preconceptions. Consider, first, the assumption that for your partner to feel interest in someone else is a sign of dissatisfaction with you, a sign that you are “not enough” for him. Implicit in this idea is a view of relationships as driven by a need to correct for deficiency. In such a view, being a good partner is like filling an empty receptacle: If you do your job well, there is nothing left to be filled, nothing that your partner could possibly gain from having another partner. Thus, if your partner does become interested in someone else, it must be because of some deficiency in your partner’s life that you’ve failed to offset, some portion of the receptacle that you’ve failed to fill. But this is a false and pernicious view of relationships. It’s not—or at least, it need not be, and arguably should not be—as if we form relationships as a way of correcting for some problem or deficiency in our lives; rather, we form relationships because they are a source of value within our lives and within the lives of our partners. And there’s no tension between having a perfectly fine relationship with one partner while acknowledging that additional relationships could make for additional sources of value within our life and within the lives of others.15

Once more, we might consider an analogy with friendship. To make a new friend is no indication at all that there’s something wrong with an existing friend. It doesn’t even remotely suggest that the existing friend “isn’t enough.” (And let’s imagine now that the existing friend did confront us with such a charge. “What’s wrong—am I not enough for you?” he demands. How sadly neurotic, how appallingly petty and immature this would be!) After all, at least in typical, healthy cases, we form friendships not to correct for some deficiency, but to add a source of value to our lives and to the lives of our friends. The same, it seems, holds true for love. Just as we have no reason to feel hurt when a friend of ours makes an additional friend, we have no reason to feel hurt when a partner of ours finds an additional partner.

Consider, next, the fear that is so central to jealousy: that of losing a partner to someone else. When in the grip of this fear, we often forget to ask ourselves a simple yet crucial question: If our relationship is mutually fulfilling, shouldn’t we trust our partner not to leave us for someone else? Of course, for many of us, being monogamous will have made this a more difficult question to answer. As noted earlier, under monogamy the stability of our relationship is not just a matter of whether it’s fulfilling on its own terms; rather, it’s likely also to be a matter of whether our partner perceives other potential relationships as more fulfilling. To the extent that she does, she’ll have reason to leave us for someone else. But let’s assume here that we’ve already taken the first step toward overcoming jealousy, namely abandoning monogamy. Absent monogamy, for our partner to suspect that another relationship would be fulfilling, or even more fulfilling than his relationship with us, need not present a reason for him to leave us. For we’ve left it open to him to pursue others while staying with us; we haven’t forced him to choose between us and another. With this in mind, let’s come back to the above question: If our relationship is mutually fulfilling, shouldn’t we trust our partner not to leave us for someone else? It appears so. That our partner would leave us for someone else—and would leave us despite being in a mutually fulfilling relationship with us—does not seem like the kind of prospect toward which it is reasonable to harbor so much fear. By realizing and reflecting on this, we are likely to loosen the fear’s hold on us. (And what if our relationship is not mutually fulfilling? Then, presumably, it is not worth maintaining in the first place. For our partner to leave us for someone she’s happy with would then be something to be welcomed, not feared.)

Admittedly, there are circumstances that make more salient the prospect of your partner’s leaving you for someone else. For example, what if your partner discovers that she would find being with a certain other person even more fulfilling than being with you, yet this other person lives far away, in someplace you cannot move to? In order to be with the other, your partner would have to move away from you. In cases like this, it might seem that there’s good reason to fear that your partner will leave you for someone else. It might seem, further, that monogamy would function as a kind of protective barrier here; if two partners have decided to restrict themselves from sex and romance with outsiders, then each partner is less likely to discover that there is someone else with whom he has better sex, to whom he feels a deeper romantic connection, or with whom he otherwise gets along better.

Yet there is something puzzling, if not deeply unsettling, in the hope that your partner will remain ignorant of options that are better for her. While seeing your partner abandon you for another is no doubt painful, consider the nature of the alternative just described: a case in which your partner stays with you only because, given monogamous restrictions, she has not experienced a certain other person—a person whom she would in fact be happier with. Is that really that desirable a state of affairs? Indeed, is it not that state of affairs that we should be more concerned to avoid here? When leaving us for someone else is the path to a more fulfilling romantic life for our partner, should we not want that for him? However much it may crush us to see our partner leave us behind in this way, our love and care for her should lead us to want what’s best for her. Even when it is reasonable, then, to suspect that our partner will leave us for someone she’s happier with, that is a prospect to be welcomed rather than feared.

To welcome such a prospect might seem to require a high degree of emotional independence from one’s partner—and, indeed, it almost certainly does. By “emotional independence” here I do not at all mean a lack of love or affection, but rather, being comfortable with oneself, satisfied with oneself, secure in oneself. To be emotionally independent in this sense is to understand that, however much one treasures one’s relationship, one does not require one’s partner for one to happy; one could still live a deeply fulfilling life even if one’s partner decided to leave. The more one attains this kind of emotional independence and maturity, the less one is likely to suffer from the insecurity that lies at the core of jealousy. As ever, the most genuine security comes from within. Just as one should be prepared to face life should one’s partner die, one should be prepared to face life should one’s partner decide to leave.

Abandoning monogamy, recognizing the irrationality of jealousy, and cultivating emotional independence are together a foundation for overcoming jealousy. Of course, they do not guarantee that one will never feel jealous at all. Many nonmonogamous relationships involve occasional moments of jealousy. But then, many non-monogamous relationships have likewise been the site of partners’ discovering powerful ways of coping with and working through their jealousy. Such experiences suggest that jealousy is not something to which partners in a non-monogamous relationship must resign themselves. Rather, when partners in a non-monogamous relationship find themselves feeling jealous, they can simply accept it as a challenge to be managed constructively, much like other challenges that arise in relationships.

3 Conclusion

With that I conclude my responses to what are, in my view, the most prominent defenses of monogamy. If my responses are on the mark, these defenses all fail. Of course, there are other, less well-known defenses. Regrettably, I cannot respond to them here. And even if these further defenses likewise fail, there remains the possibility that newer, better defenses of monogamy will arise. Still, given the apparent failure of what might have seemed its flagship defenses, monogamy is in a bad way. Unless some other defense turns out to succeed where its more prominent forerunners have failed, monogamous restrictions will, by all indications, be analogous to the morally troubling restriction on having additional friends. Thus, while the case I’ve advanced against monogamy is not conclusive, it is, at the very least, suggestive. However far the matter remains from being settled, the evidence thus far points largely in one direction: We morally ought to reject monogamy. Just as one morally ought to allow one’s partner to have additional friends, one morally ought to allow one’s partner to have additional partners.

A few final clarifications are called for. First, in suggesting that non-monogamy is morally required, I’m not suggesting that partners have no right to be monogamous. That is, I’m not suggesting that partners ought to be coercively prevented from holding one another to monogamous restrictions (whatever such coercive prevention would mean in practice). Even if a certain restriction is immoral, partners could still—and, I believe, often or typically do—have the right to hold one another to it. This, at any rate, is what I take the case to be with monogamy. Partners indeed have the right to be monogamous, though that does not suffice to make monogamy right.

Second, at this point some might feel a lingering worry: Isn’t non-monogamy a radical lifestyle change? Could people really be expected to abandon so much of what is familiar to their romantic life? In fact, however, non-monogamy need not pose as radical a lifestyle shift as it might seem. Contrary to what people often assume, being non-monogamous does not mean that one must maintain multiple relationships at a time. After all, one can be non-monogamous and in a relationship with only one person at a certain time—for example, in a case in which one simply hasn’t found others in whom one is interested. For that matter, one can even be non-monogamous while single, just as one can be monogamous while single. What being non-monogamous means, rather, is simply that one is open to having multiple relationships at a time—open in the sense of rejecting restrictions thereon—both for oneself and whatever partners one might have.

Thus, even if you have little desire to pursue multiple relationships at a time, you can live accordingly while remaining non-monogamous. You can stick to relationships with only one person at a time; the key is simply that you remain open to your partner’s having multiple relationships at a time, should she desire it. Now, if your partner likewise has no interest in pursuing multiple relationships at a time, then your relationship with him will, from a certain distance, appear no different from a typical, monogamous relationship. Crucially, though, in being non-monogamous, you and your partner would both remain open to having multiple relationships at a time. That is, you and your partner would recognize that if either of you does come to desire an additional relationship, neither of you will in principle stand opposed to pursuing it. It is this openness, rather than the actual state of being in multiple relationships at a time, that is the essence of non-monogamy.