Occasionally, then, the behaviors and values of another species resemble our own enough that we experience a flash of recognition . . . and so, in looking for animal morality, we make the first mistake, which is to search for a system of values that perfectly reflects our own.

This intellectual error, the search for human values made manifest in the lives of animals, is easy to parody. It's like dressing elephants in tutus. But in the wrong hands it can also become a serious or even a dangerous error. Theorists of a Western liberal inclination sometimes look for animals whose lives seem to manifest their own human ideal of an unusual generosity, sharing, cooperation, egalitarianism, and all-round niceness; and when they don't find such an animal, occasionally they try to invent one--by, for example, dishonestly promoting a vision of chimpanzees as far nicer than they really are. Meanwhile, theorists of a harsher, more authoritarian bent sometimes look for creatures who manifest high levels of obedience and self-sacrifice: the subordination of the individual to the welfare of the larger community. Honeybees might be a good example here, but do they represent the ideal model for human morality? The Nazis thought so, and thus they tried to enlist Europe's foremost expert on honeybees and honeybee communication, Karl von Frisch, to help promote their ideology. Von Frisch would have none of it, and neither should we.

Saint Thomas Aquinas argued that "natural" was equivalent to "good," which meant that one could make moral judgements by appealing to naturally-occurring examples. Aquinas argued that the Creator could only create a nature that was morally good; we see Aquinas' position echoed in contemporary times when people say that homosexuality is immoral because it's unnatural.

The British philosopher G. E. Moore presented in his Principia Ethica (1903) a contrary position. He argued that ethical qualities such as "good" or "bad" are unrelated to natural qualities, such as "pleasant" or "desirable" or "attractive." Moore solidified his own stance by branding the opposing point of view as a formal logical fallacy: what he called the naturalistic fallacy. You can't say something is moral because it's natural, so this idea goes, and you can't call something immoral because it's unnatural.

Who is right, Aquinas or Moore?

Actually, neither. On the one hand, human and non-human moral systems derive from the natural process of Darwinian evolution. In that sense, then, our human morality is based on nature, and it can be explained and tested by reference to naturally-occurring events. On the other hand, while evolution gives us and other social species morality in general, the particulars will vary according to any particular species' ecological circumstances and a complexly evolved response to them. So, while I will promote the idea of morality as a gift of nature working through evolution, let us not think of the lives of emperor penguins or chimpanzees or honeybees or any other animals as if they will manifest specific, particularized instances of what is right or wrong in the lives of humans.

In my last post, I presented bonobos (pygmy chimpanzees) as a species with an expressive and diverse sexuality that includes a lot of homosexual behavior. As I noted then, bonobos weaken the argument that homosexuality is "immoral" because it's "unnatural." (At least one reader presumed, in error, that I was making the reverse argument: that bonobos demonstrate human homosexuality is "natural" and therefore "moral." Not at all what I wrote.) Bonobos are one of at least 63 mammalian species known to engage in homosexual behavior, either commonly or sporadically. For birds, homosexuality has been observed in 94 species. So homosexuality is relatively widespread in the animal kingdom, and for many species it's an aspect of their normal, "natural" behavioral repertoire. Homosexuality may be common enough among humans to describe it as "natural" for us as well-and yet homosexuality is still commonly regarded as "immoral" and thus is legally banned in almost eighty nations around the world, with the punishments for a violation including death in at least six.

These facts may seem to suggest that the moral rules, often translated into legal ones, are not a reflection of nature but rather of nurture: of society or culture. That's the common error of overly simplistic, either/or thinking. The moral rules express both nature and nurture, or, as I more usually describe it, the rules are simultaneously psychological and social.

Sex and sexuality present a realm of social contact so wrapped in significance and fraught with conflict that we can readily predict the evolution of rules--moral rules--that moderate or regularize the nature of sexual behavior for any social species. What we commonly regard as sexual morality, then, consists of a series of psycho-social rules regarding the expression of sex and sexuality: who may mate with whom and under what circumstances. The psychological aspect of those rules, placed by evolution into the minds of all individuals, might be imagined as an embedded map of desire, or a neuro-chemically-based series of inclinations and inhibitions. The social aspect of those rules appears largely in the form of their enforcements, where socially more powerful individuals press their own inclinations and inhibitions upon the socially less powerful. Whether homosexuality is moral or immoral in any particular human society, therefore, amounts to a collective decision made by those with the greater social power.

Is homosexuality moral or immoral? That might be an interesting question, but the more pertinent one is this: Why should anyone care? What evolutionary process or event has caused people to have the fears, concerns, interests, and orientations they have about their own and others' sexuality?