Nature Is Gay
Sometimes I feel that I am one of the only two queers in all of Christendom who are prepared to affirm something called “natural law.” (The other, by a stroke of great good luck, happens to be my boyfriend.)
A definitional issue. I do not mean to subscribe (yet) to any particular school of natural law, though of course I have my own preferences. Aristotelian virtue-ethicists, Roman Stoics, patristic moral theologians, medieval Latin scholastics, and liberal and international human-rights lawyers can all be considered as subscribing to a version of the “natural-law ethical tradition” in the widest sense. That tradition’s core commitments, as I understand them, are to the propositions that the good life is discoverable by unaided human reason, and that moral precepts are observable in nature (be it the internal, “spiritual” nature of the reasoning mind, and/or the external, physical nature investigated by empirical scientists). These commitments are both purely practical—how else is any meaningful ethical reflection cutting across time, place, and even between individual persons of differing experiences, possible?—and also properly theological—as God is One, there cannot be two different and competing gods (one of reason, another of faith).
I will not rehearse just now all the familiar natural-law arguments which have been mounted against homosexuality. I want instead to emphasize two points which are usually neglected by those who profess and teach natural law, especially in Roman Catholic universities.
The first point is that the substantive content of the natural law is subject to change over time. The most famous and agreed-upon example in the works of Christian natural lawyers is, surely, private property. This was unknown before the Fall, but property possession became natural (Thomas Aquinas actually uses the verb mutare ) given the realities of post-lapsarian human nature. Another example, also very famous if slightly less agreed-upon, is the taking of interest on a loan. Most patristic and scholastic authorities condemned it unequivocally, as indeed Muslims continue to do today, and Dante treated usurers equally alongside sodomites in the seventh circle of his Inferno; a judgment which arguably made sense in the context of an overwhelmingly rural society dominated overwhelmingly by agricultural production and short-distance trade. But beginning with Pope Leo X’s bull Inter multiplices in 1515, ecclesiastical authorities approved the taking of modest interest on loans, and compensating merchants for the risks they undertook in long-distance trade.  I am not sure that homosexuality is best compared with these specific developments in the natural law, but I want to suggest that conservatives need not fear, of necessity, that the acceptance of new ideas about homosexuality would require the theory of natural law to be jettisoned. On the contrary, Justinian’s Corpus iuris civilis—which was widely regarded, during the Middle Ages, as the perfect positive instantiation of the natural law, and Justinian himself, author of the Ho Monogenes in the Byzantine Mass, venerated as a saint in the Eastern church—acknowledged the law’s mutability:
Things divine are perfect, but the character of human law is always to hasten onward, and there is nothing in it which can abide forever, since nature is eager to produce new forms [my emphasis]. We therefore do not cease to expect that matters will henceforth arise that are not secured in legal ties. Consequently, if any such case arises, let a remedy be sought from the Augustus, since in truth God has set the imperial function over human affairs, so that it should be able, whenever a new contingency arises, to correct and settle it and to subject it to suitable procedures and regulations. We are not the first to say this. 
The second point about the natural law which deserves especial emphasis is that the tradition’s fundamental sources are not nearly so hostile to homosexuality as the tradition’s later exponents. Aristotle, our philosophical master here as elsewhere, was neither much interested in nor favorable to the notorious Cretan and Theban custom of pederasty, but he was prepared to acknowledge that at least some pederasts were motivated by nature, and not only by habit:
[There are …] morbid states resulting from custom, e.g., the habit of plucking out the hair or of growing the nails, … and in addition to these paederasty; for these arise in some by nature and in others, as in those who have been the victims of lust from childhood, from habit. Now those in whom nature is the cause of such a state no one would call incontinent [my emphasis], any more than one would apply the epithet to women because of the passive part they play in copulation…. 
Considering how Aristotle was subsequently used by the Fathers and Doctors of the Christian church, it is extraordinary to realize that Aristotle himself, in one of his few statements on the topic, argued that naturally-occurring homosexual behavior was no more blame-worthy than cutting one’s hair or nails, or than being female.
When the growth in contemporary knowledge about the origins of homosexuality is also taken into consideration, the ethical argument against it on purported natural-law grounds quickly becomes untenable. In medieval biology, for which the hyena was the only animal known to be “hermaphroditic,” one might regard queers as genuine monstrosities of nature; but no longer. To hyenas we have now added penguins, mallard ducks, black swans, Amazon dolphins, giraffes, lions, bonobo monkeys, Japanese macaques, and hundreds of others. In human males, moreover, the “most consistent biodemographic correlate of sexual orientation” is the number of older brothers, perhaps due to the nature of hormonal washes in the mother’s womb. Even the traditional Christian complaint that homosexuality is anti-procreative is open to question on evolutionary grounds. A 2008 study by Andrea Camperio Ciani found that “homosexuality is just one of the consequences of strategies for making females more fecund.”
Hypothesis: homosexuality may very well prove to be in accord with nature, after all. If it does so, should the debate not shift from whether Christians ought to maintain the traditional doctrine, to how they ought rather to go about revising it? Would not Chrysostom, Augustine, Aquinas, et. al., following their own logic, agree? And does it not matter?