In one of the classes I teach at Baylor University, we cover, among other topics, the issue of marriage. I begin by asking my students, “Is there a difference between these two questions: ‘How do you define marriage?’ and ‘What is marriage?’” Most of them say “no,” which implies that they believe that defining and discovering are pretty much the same sort of activity.

I then ask, “Is there a difference between these two questions: ‘How do you define a human person?,’ and ‘What is a human person?’?” Initially, most say “no,” but their confidence wanes once I press them: “So, suppose that Mr. X, a slave owner, defines a human person as ‘a human being of the Caucasian race.’ Is he correct in his definition?” The students quickly respond with an emphatic “no,” to which I reply, “But doesn’t that mean that defining and discovering are not the same activity? After all, your rejection of Mr. X’s definition implies that a definition can be wrong if it is inconsistent with the nature of the thing the definition was meant to describe.” We then move on to discuss the differences between nominal and real definitions, essential and accidental properties, and whether the law—in the case of marriage—should or should not recognize only those unions that are real marriages (whatever those may turn out to be).

Unsurprisingly, they all wind up agreeing in principle that the state should only recognize “real marriages,” just as our welfare policy should only try to remedy real poverty, our criminal law should only proscribe real crimes, our contract law should only honor real contracts, and our public school science classes should only teach real science. Regardless of the post-modern rhetorical sophistry they have uncritically assimilated from the wider culture, they inevitably confess, when pressed in just the right way, that they are closet realists. They viscerally grasp that the only intellectually legitimate answer to the question “Why should we believe what is real?” must be the real answer. The unreal answer, they apprehend, can never in principle be the right answer.

Of course, on the question of marriage and the law’s recognition of it, this is only a first step in addressing this question. After all, some of them support the legal recognition of same-sex partnerships as marriages, while others do not. Their disagreement, therefore, is not over whether the law should recognize real marriages; on that, they all agree. Rather, they disagree on what counts as a real marriage.

Framing the Marriage Question

This way of framing the question of marriage and its legal recognition, though it offers both sides of a contested question a common ground from which to argue for their positions, has been almost universally absent from the way the debate is presented in popular culture. And yet, this seems to be the only substantive question whose answer is capable of providing us with real direction in deciding what policy is the most just.

This is why the new book by Patrick Lee and Robert P. George—Conjugal Union: What Marriage Is and Why It Matters—is such an important philosophical contribution to both the legal and policy discussions on marriage. Published by Cambridge University Press, the book provides a careful and systematic defense of what is often labeled “traditional marriage.”

Because of our culture’s uncritical embrace of chronological snobbery—i.e., new is always better than old—the unfortunate term “traditional marriage” not only implies that “marriage” is merely a noun in front of which any adjective can be placed without affecting the noun’s substantive meaning; it also implicitly assumes the non-normativity of “traditional marriage.” Imagine, for example, one were to place the adjective “male” in front of the term “lesbian.” This would not merely modify the term “lesbian.” Rather, it would create a whole new term, referring to a different thing: a biological male who believes himself to be a woman who is sexually attracted almost exclusively to biological females. In this new term, “male” does not function like “tall,” “short,” “black,” or “white.” It is more like placing “dead” in front of “man” and pretending that a “dead man” is just a type of man rather than a whole new thing.

These examples illustrate what Lee and George maintain is a largely unevaluated assumption in the debate over marriage: the idea that placing “same-sex,” “gay,” “polyamorous,” or even “traditional” in front of the term “marriage” merely modifies the latter and does not affect its substantive meaning. Thus, same-sex marriage is not a new thing; it is merely a new sort of the same thing, as would be the case if we discovered a red-and-white-striped horse and concluded that despite its strange appearance it was still just a horse. Within such a conceptual framework, it seems to make sense for many people that when the government excludes same-sex couples from legally recognized marriage it is no different from the government excluding tall, short, black, or white opposite-sex couples from the institution.

New Natural Law and the Is-Ought Distinction

Conjugal Union is a small book (143 pages) consisting of five chapters. After the introductory first chapter, the authors move on in chapter two (“Human Nature and Morality”) to offer a brief defense of the New Natural Law (NNL), a moral theory that they will employ throughout the book. Offering a concise and clear defense of this view, including an account of the basic human goods and practical principles, Lee and George situate it between what they believe are two mistaken extremes: Hedonism and Naturalism.

Hedonists believe that “as long as sexual activity is consensual and not overridden by bad consequences (the transmission of disease, for example) it is morally permissible.” That is, as long as one’s preferences are satisfied in consensual acts that do not harm others, no moral wrong has occurred. By contrast, Naturalists, often associated with what some call the Old Natural Law (ONL), maintain that the wrongness of certain sexual acts depends on whether they are contrary to nature. So, for example, contraception is morally wrong because the good to which our reproductive powers are ordered is reproduction. This is why celibacy and natural family planning are not immoral, since they may be employed in ways not contrary to the good to which our sexual powers are ordered. It is like the difference between fasting and bulimia.

Although Lee and George probably agree with the Naturalists on virtually every moral issue, they think the Naturalists “commit what has come to be called the naturalistic fallacy, namely, deriving a moral-ought conclusion from premises all of which are is-propositions (i.e., descriptive propositions).”

This is a standard and uncontroversial claim among New Natural Lawyers (NNLs), and, as one would guess, deeply controversial among Old Natural Lawyers (ONLs). Because this is not the venue to pursue this debate, I will only register my misgivings regarding the charge that the ONLs commit the “naturalistic fallacy.” However, one need not accept the NNL in order to embrace the central argument for marriage in this book, for in several places the authors seem implicitly to rely on the formal and final causality defended by the ONLs. (They would, of course, disagree).

What Marriage Is

Chapter three, “What Marriage Is,” is the most important in the book. Lee and George argue that marriage is a two-person opposite-sex community that has three essential characteristics: conjugality, permanence, and exclusivity. To show why this understanding is the most rational, they begin with an uncontroversial case—male-female marriage—and from that draw out those properties and practices that distinguish marriage from other sorts of communities or friendships.

This is not unlike how one may try to understand the natures of other things. So, for example, in order to figure out what a human being is, I begin with a paradigm case: a healthy adult member of the species homo sapiens. Suppose, after much reflection, I conclude that a human being is by nature a rational animal that walks upright on two legs. There are, of course, other two-legged creatures, though they are not rational animals. On the other hand, there are human beings that do not have two legs, do not walk upright, and cannot exercise their rational powers, yet they are still human beings. How can this be? It is because our reasoning from the paradigm case to a conclusion about human nature is not a mere statistical generalization of the current abilities of most human beings, but rather, a real definition of the sort of thing a human being is. This is why we can say that the woman without legs, the child who cannot walk upright, or the comatose man who cannot engage in rational deliberation is fully human—but the dog, cat, and tree are not.

Lee and George believe one can do the same with “marriage” as we just did with “human being.” There are, they argue, identifiable characteristics of marriage that distinguish it from other friendships and communities. When we look at the paradigm case, it is clear that marriage must be at its root a conjugal union. After all, why would marriage have arisen if not for the fact that only men and women have complementary reproductive powers that allow them to unite organically and are intrinsically ordered toward the begetting and raising of children, who need parents who are committed to them and to each other? This also explains the norms of exclusivity and permanence. As part of their case, Lee and George survey other sorts of friendships and explain why they are not marriages, and they also explain why other types of procreative and child-rearing partnerships do not qualify as well.

Lee and George also argue that it is important not to confuse the marital norm of conjugality with the good to which the conjugal act is ordered, procreation. As they note, several judges in some high-profile marriage cases, have interpreted the arguments for male-female marriage as requiring procreation. But clearly no opposite-sex couple has ever been forbidden by any state to marry if their union cannot produce children or they are unwilling to have children. So, the judges reason, how can one deny same-sex couples legal marriage if they are just as incapable of procreating as some opposite-sex couples? The answer, Lee and George maintain, is simple: conjugal union is not an instrumental good, but an intrinsic good whose perfection is the begetting and raising of children. If the perfection is never actualized, for reasons of age, choice, or sterility, the nature of the act is not changed, just as the nature of the comatose man is not changed simply because the perfection of his rational powers cannot be actualized.

For this reason, same-sex couples and opposite-sex couples are not similarly situated, since conjugal union is literally impossible between persons of the same sex. To put it another way: sterility is a privation of conjugality, whereas the absence of conjugality is the privation of nothing. All same-sex couples, whether or not they are romantically involved and regardless of their sexual orientation, are as “sterile” as the Pietà is “blind.”

Lee and George, of course, are not suggesting that the partners in a same-sex relationship cannot experience deep romantic love for one another. Their point here is quite modest: to explore, with a level of philosophical sophistication, the nature of marriage. The nature of romantic love and its varieties, whether same-sex or otherwise, is a separate, though important, topic.

Not Sentiment, Prejudice, or Tradition

Chapter four addresses the moral status of non-marital sexual acts, such as fornication, sodomy, masturbation, bestiality, and incest. Not surprisingly, Lee and George conclude that these acts are all immoral, largely based on the nature of the marital norms defended in chapter three.

Given the degree to which our culture has become increasingly permissive on sexual matters, this chapter may surprise those who have been led to believe that there are no actual arguments in defense of what was once called “traditional morality.” In an age in which that morality is not so much addressed as it is ridiculed, this chapter shows why ridicule is the chosen instrument of critique by a sizable segment of the popular culture: the best arguments for traditional morality are sophisticated and require a rarely practiced measure of sustained and careful attention if one hopes to criticize them with any modicum of intellectual integrity.

The book’s final chapter (“Marriage and the Law”) concerns questions about what view of marriage should be reflected in our laws. Lee and George argue that because conjugal marriage is uniquely real marriage, it would be unjust for the law to say otherwise. This chapter includes rebuttals to several arguments for the legal recognition of same-sex relationships as marriages. For this reason, Lee and George often return to points established earlier in the book and apply them to the legal debate.

Because the case for conjugal marriage is often portrayed by many, including some who sit on the federal bench, as devoid of any rational justification whatsoever, Conjugal Union is an important contribution to the literature. Even if you find yourself disagreeing with the authors on some points, as I have, they have nevertheless clearly established that the case for conjugal marriage is not merely based on some irrational prejudice or sentimental appeal to tradition—as the case is sometimes depicted by those who should know better—but rather, on a series of sophisticated arguments that deserve to be answered.