Darwinian Marriage (3): An Exchange with Matt Franck

Today, those of us in the American Midwest are confined to our homes by the Blizzard of '11. For me, it's an opportunity to think some more about "Darwinian marriage."

Matthew Franck is the Director of the Center on Religion and the Constitution of the Witherspoon Institute in Princeton, New Jersey. He is one of our most distinguished graduates at Northern Illinois University, where he earned his Ph.D. in political science, specializing in political theory.

We recently had a brief email exchange, and he has agreed to allow me to post it here.

Matt wrote:

Thanks for pointing me to your blogging on these questions. At the risk of offending an old acquaintance, I will say that I am less and less taken all the time with Darwinian explanations for anything, especially for human behavioral phenomena, and most especially for the explanation of moral norms and their genesis. Your note came just as I was reading Marilynne Robinson's ABSENCE OF MIND, which uses the term "parascience" for the work of, e.g., E. O. Wilson. I think she has something there.

In response to this, I wrote:

But, then, if I understand you correctly, you are impressed by Robert George's biological explanations for moral norms and their genesis, as in his "What is Marriage?" article. If so, then you would agree with him that, for example, marriage would not be a moral norm if human beings reproduced asexually. Right? So our moral nature really does depend on our biological nature as sexual animals who are adapted for conjugal bonding and parental care? That's Darwin's argument for the biological basis for the moral sense.

Responding to this, Matt wrote:

It seems one of us is confused, and I do not rule out that it may be me. But as I understand the argument of George and his co-authors, they are not offering "biological explanations for moral norms and their genesis." Rather, they are tyring to provide a rational understanding of the nature of marriage, as a politico-legal and moral institution, by taking account of our nature, in its fullness, as bodily creatures. It is one thing to say that our biological nature is relevant to moral considerations, and quite another to say that our biology is the cause of our morality.

I agree that if human beings were "made" (whether by design or by evolutionary adaptation) to reproduce asexually, there would be no such thing as marriage. We are instead made--or "adapted"--for conjugal relations. But as we know, the sexual urge (whatever its genesis) is capable of manifesting itself in manifold directions, some of them useful for procreation, some not, and many of the paths down which the sexual urge travels can result in reproductive activity we can condemn as immoral: rape, incest, adultery, polygamy, premarital fornication . . . I cannot see any "Darwinian" grounds on which to condemn any of them, or any of the nonreproductive manifestations of the sexual urge, for that matter: homosexuality, anal and oral sex, sadomasochism, masturbation, bestiality . . . These are not useful activities for the perpetuation of the species, but that does not conclude the question of their morality.

The moral sense seems to have a biological "cause" only in a material sense, as a table's material cause may be the tree from which the wood came. Assuming that Darwinian accounts of biology have any explanatory power for the understanding of human behavior--which I assume here only arguendo--they have nothing meaningful to say about the moral norms governing our judgments of human behavior as right or wrong. For these purposes, we require formal and final causes of morality that cannot be located in our biology.

It is possible that Darwinian explanations shed light on "what people do, by nature, for the most part." (Frankly, I doubt it, but that's another debate.) Granting such a possibility, it does not follow that Darwinian explanations shed light on "what is right or wrong for people to do in pursuit of that human flourishing that truly fulfills our nature." It is the latter sort of argument--speaking of "nature" in teleological terms quite alien to modern biological science--that George et al. are attempting in their consideration of marriage.

As I read this, Matt's argument is that while our biological nature explains the material causes of morality, it does not explain the formal and final causes of morality. If we want to understand what is right or wrong for us "in pursuit of that human flourishing that truly fulfills our nature," which is the concern of George and his co-authors, then we need to speak of nature in teleological terms that are "quite alien to modern biological science."

A Darwinian explanation of morality is defective, therefore, according to Matt, because it asserts a materialist reductionism and denies natural teleology, which contradicts the sort of Aristotelian/Thomistic naturalism manifest in the writing of George and his co-authors.

In reply, I argue that Darwinian ethics is not reductionistic, because it recognizes the emergent complexity of human moral evolution, and it affirms natural teleology, because while it rejects cosmic teleology, it recognizes the immanent teleology in the goal-directed activity of life.

Both of these points can be supported by a careful reading of Darwin himself--particularly, his account of the human moral sense in The Descent of Man (Penguin Books, 2004).

Darwin might seem to be a reductionist when he declares that "there is no fundamental difference between man and the higher mammals in their mental faculties," because "the mental faculties of man and the lower animals do not differ in kind, although immensely in degree" (86, 173).

But Darwin implicitly recognizes that differences in degree passing over a critical threshold can create emergent differences in kind. In the case of human beings, emergent evolution creates at least three points of human uniqueness.

First, human beings are unique in their self-conscious awareness. "It may be freely admitted that no animal is self-conscious, if by this term it is implied, that he reflects on such points, as whence he comes or whither he will go, or what is life and death, and so forth" (105).

Second, humans are unique in their capacity for language. "The habitual use of articulate language is . . . peculiar to man" (107).

Third, humans are unique in their nature as moral beings. "A moral being is one who is capable of comparing his past and future actions or motives, and of approving or disapproving of them. We have no reason to suppose that any of the lower animals have this capacity" (135).

The uniqueness of human morality, Darwin recognized, comes from the human combination of five kinds of intellectual powers--the social instincts that lead humans to feel sympathetic concern for others, the mental faculties that allow humans to judge present actions in the light of past experience and future expectations, the capacity for language that allows a human society to express its approbation or disapprobation of conduct, and, finally, the human capacity for learning by habituation (121-22).

From this, Darwin concluded, "our moral sense or conscience becomes a highly complex sentiment--originating in the social instincts, largely guided by the approbation of our fellow-men, ruled by reason, self-interest, and in later times by deep religious feelings, and confirmed by instruction and habit" (157). Consequently, the moral progress of humanity has come mostly through cultural evolution, as human beings learn by experience what is most conducive to their individual and social happiness (163, 169, 682, 688-89). One fundamental feature of that moral progress is the extension of moral concern to ever-wider circles of humanity based on the golden-rule principle of justice as reciprocity, which "lies at the foundation of morality" (147-49, 151, 156-58).

This human moral experience is teleological in the sense that we act for the sake of those natural ends or purposes that we judge to be fulfilling of our natural desires. Darwin's science of evolution denies any form of cosmic teleology, which would present the evolution of the world as a progressive unfolding of a design somehow inherent in the beginning. But denying this sort of cosmic teleology does not subvert the Aristotelian teleology manifest in human morality.

Contrary to Matt's assertion that natural teleology is "quite alien to modern biological science," teleological reasoning is a necessary part of modern biology. Ernst Mayr was one of the most prominent evolutionary biologists of the past century. And he insisted: "Aristotelian why-questions have played an important heuristic role in the history of biology. 'Why' is the most important question the evolutionary biologist asks in all of his researches" (1982, p. 89).

Although Darwinian biologists have to be skeptical about any cosmic teleology, they see Aristotelian teleology in the goal-directed life of organic entities and processes as natural adaptations shaped by evolutionary history. After all, even Aristotle himself, who was a biologist, looked to biological phenomena as displaying the clearest manifestations of natural teleology.

Therefore, to apply functional reasoning to derive moral judgments from biological facts does not violate the spirit of modern evolutionary biology. From the perspective of Darwinian biology, it is reasonable to maintain that the human species has evolved to show natural inclinations that separate human beings from other animals, and that the fulfillment of these natural inclinations in moral and political life conforms to the purposes of our evolved human nature.

As I have indicated in some other posts, Thomas Aquinas rooted his understanding of natural law in the biological science that he had learned from Aristotle and Albert the Great. Arguing that "the good is the desirable," Aquinas could explain natural law as the satisfaction of natural desire, so that "everything to which human beings are inclined by their nature belongs to the natural law" (ST I, q. 5, a. 6; I-II, q. 94, aa. 2-3). He could see the levels of natural law as corresponding to the generic traits that human beings share with some other animals, the specific traits that are unique to human beings generally as a species, and the temperamental traits that vary across individuals.

The biological character of Aquinas's reasoning about natural law as rooted in natural desires is clear in his account of marriage and familial bonding. Citing Ulpian, Aquinas declares that marriage is natural because it satisfies natural desires that human beings share with some animals. He speaks of the human disposition to marriage as a "natural instinct of the human species" (ST, II-II, q. 57, a. 3; Suppl., q. 41, a. 1; SCG, bk. 3, chap. 123).

On Aquinas's account, the primary natural end of marriage is to secure the parental care of children, while the secondary natural end is to secure the conjugal bonding of male and female for a sexual division of labor in the household. Among some animals, Aquinas observes, the female can care properly for her offspring on her own, and thus there is no natural need for any enduring bond between male and female. For those animals whose offspring do require care from both parents, however, nature implants an inclination for male and female to stay together in order to provide the necessary parental care. Just as is the case for those animals whose offspring could not survive or develop normally without parental care, human offspring depend upon parents for their existence, nourishment, and education. To secure this natural end, then, nature instills in human beings natural desires for sexual coupling and parental care. Even if they do not have children, however, men and women naturally desire marital union because, not being self-sufficient, they seek the conjugal friendship of husband and wife sharing in household life.

Aquinas can see the naturalness of monogamy, the partial naturalness of polygyny, and the unnaturalness of polyandry based on his understanding of the biological nature of marriage as directed to the natural ends of parental care and conjugal bonding.

Darwinian science confirms this biological understanding of marriage as rooted in evolved human nature. The Darwinian account of marriage was first stated by Darwin himself and then elaborated by Edward Westermarck. More recent research has filled in this science by explaining the genetic, neurophysiological, and cultural bases of marital bonding.

In "What is Marriage?," George and his co-authors revive Aquinas's biological account of marriage. Darwinian science supports that account by explaining its roots in evolved human nature.

But what about the moral debate over homosexuality and gay marriage, which is the primary concern of the article by George and his co-authors? What would a Darwinian ethics suggest about how we should conduct this debate? If we look to what Darwin says about the various elements of the moral sense, we can see the various considerations that go into such a debate. First, a moral sense requires a sympathetic concern for our fellow human beings and for principles of justice as reciprocity. In the past, the hatred for homosexuals has motivated legal punishment for their behavior, as in the Old Testament teaching that homosexuals should be stoned to death. But now, most of us--including people like George--recognize that this is wrong, because homosexuals should elicit enough fellow-feeling from those of us who are heterosexual that we will refrain from persecuting or killing them. Clearly, Old Testament religion has not provided proper moral guidance on this issue.

We can see that homosexuality is unnatural to the extent that it cannot eventuate in natural procreation. But, of course, homosexuals can become adoptive parents and thus satisfy their natural desire for parenting. Moreover, homosexuals can satisfy the natural desire for conjugal bonding, regardless of whether they become parents.

Since much of morality turns on social approbation or disapprobation based on what we judge to be the common good of society, and since heterosexual marriage and parental care are naturally important for the common good, we need to decide whether or not homosexuality and gay marriage pose any danger to the goods of heterosexual marriage and parental care.

George and his co-authors think that legalizing gay marriage will destroy heterosexual marriage and parental care. How plausible is that? If heteosexual marriage really is as deeply natural for most human beings as they say it is, how likely is it that it would disappear if gay marriage were to be generally legalized? I don't find this very likely. Moreover, I suspect that lesbians are likely to be more faithfully monogamous (on average) than are heterosexual men. But, of course, this question, like all the others related to the gay marriage debate, is a question of practical judgment that can only be settled by practical experience.

Darwinian ethics would suggest that morality depends mostly on social habits and customs shaped in civil society--in families and other social groups. It would seem, then, that the institutions of marriage and family life depend more on the spontaneous orders of society than they do on legal coercion by the state. George and his co-authors disagree. They think that marital institutions are impossible if they are not created by legal licensing. On the other hand, much of what George and his co-authors say about marriage as having a moral reality independent of the state contradicts what they say about the necessity of legal licensing.

Even if many of us conclude that homosexuality is immoral, and therefore that it should be open to social disapprobation, it's not clear that the social good would be served by enforcing this social norm through legal coercion. Surely, most of us can recognize the practical wisdom in Aquinas's principle of liberal jurisprudence that it is not proper for human law to prohibit all vices. For, as Aquinas writes:

Human law is established for the collectivity of human beings, most of whom have imperfect virtue. And so human law does not prohibit every kind of vice, from which the virtuous abstain. Rather, human law prohibits only the more serious kinds of vice, from which most persons can abstain, and especially those vices that inflict harm on others, without the prohibition of which human society could not be preserved. For example, human laws prohibit murders, thefts, and the life (ST, I-II, q. 96, a. 2).

This liberal principle of jurisprudence seems to have been adopted by the New Testament Christians. For example, Paul warns the Corinthians against sexual immorality (such as incest), and he recommends that those committing such immorality be banished from their religious community. But, otherwise, he teaches toleration. "It is no concern of mine to judge outsiders. It is for you to judge those who are inside, is it not? But outsiders are for God to judge" (I Corinthians 5:12-13).

It is not surprising that John Locke quotes this New Testament teaching in his First Letter on Toleration as supporting a policy of toleration.