Thornhill and Palmer, Malamuth, and the many other investigators studying rape through an evolutionary lens, take great pains to point out that "adaptive" does not mean "justifiable," but rather only mechanistically viable. Yet dilettante followers may still be inclined to detect a misogyny in these investigations that simply is not there. As University of Michigan psychologist William McKibbin and his colleagues write in a 2008 piece for the Review of General Psychology, "No sensible person would argue that a scientist researching the causes of cancer is thereby justifying or promoting cancer. Yet some people argue that investigating rape from an evolutionary perspective justifies or legitimizes rape."
I want to rework this paragraph to see what might fall out:
Investigators studying honesty through an evolutionary lens, take great pains to point out that "adaptive" does not mean "vicious," but rather only mechanistically viable. Yet dilettante followers may still be inclined to detect a naivete in these investigations that simply is not there. As University of Burpelson psychologist Manfried Rawhide and his colleagues write in a 2079 piece for the Review of Major Pneumatology, "No sensible person would argue that a scientist researching the causes of cancer is thereby justifying or promoting cancer. Yet some people argue that investigating honesty from an evolutionary perspective condemns or undermines honesty."
The second paragraph exemplifies a rebuttal of Bulverism. Bulverism is the tactic of assuming some persons are wrong based on physiological and psychological––or, in this case, evolutionary––factors which dictate their rational biases. We may "believe in" honesty as a fundamental "moral" principle, the Bulverist argues, but this is only because we have been shaped by our evolutionary past to be so biased. Therefore, the preference for honesty, under the aegis of "morality", is just atavistic naivete, which ought to be supplanted by a truly rational ethics that is cognizant of the autonomy we know have over our own natural selection. Beren casts his vote against the Bulverists thus:
The unfortunate demonization of this brand of inquiry is rooted in the fallacy of biological determinism (according to which men are programmed by their genes to rape and have no free will to do otherwise) and the naturalistic fallacy (that because rape is natural it must be acceptable). These are resoundingly false assumptions that reveal a profound ignorance of evolutionary biology. Yet the purpose of the remaining article is not to belabor that tired ideological dispute, but to look at things from the female genetic point of view. We've heard the argument that men may have evolved to sexually assault women. Have women evolved to protect themselves from men?
Beren's point is that, just because the rape instinct is strong in numerous males, does not mean rape is therefore morally acceptable. The implication of his article, however, points in an obverse direction, namely, that because rape is bad, though natural selection has kept it going, the equally naturally selected measures of the female body against rape are a kind of good. It is interesting to note how Darwinian ethics is essentially Kantian in so far as the former rejects behavior which, if applied on a species-wide level, would lead to the degradation and dissolution of prior reproductive success. I will call this Darwikantian ethics. Kant, under the rubric of the "categorical imperative", argued that we should do only that which we believe could be practiced by everyone at all times, and abstain from that which we realize could not be practiced by all people at all times. As he writes in Grounding for the Metaphysics of Morals (tr. James W. Ellington. 3rd ed. Hackett. p. 30 (  (1993)): "Act only according to that maxim whereby you can, at the same time, will that it should become a universal law." Lying, for instance, is unacceptable because, if everyone did it––i.e. if it became literally universally acceptable––, our entire means of communication and cooperation would collapse. Likewise, Darwinian ethics rejects selfishness on the grounds that widespread selfishness––i.e. as a 'universal' feature of human behavior––would undermine ultimate reproductive stability. And "it would be bad," or at least as "bad" as a Darwinian is allowed to say something is in 'purely' adaptive terms.
Aye, there's the rub. If the basis for defending, say, altruism is that altruism has generally promoted reproductive success in the past, then we can take it as a general ethical principle that that which is morally defensible is morally defensible because it promotes reproductive success. On this principle, however, what basis do we have for condemning rape in every case? Presumably, again, the saving principle is the Darwikantian categorical imperative (DCI), but this is a feeble moral guide for at least two reasons. First, how would we define the rapist's principle for action? Does he believe it would be a universal law that every man should rape every woman under any circumstances? Certainly not, since he would certainly defend his mother and sister and other favored females against male aggressors. His principle may, therefore, be so nuanced that it could be a universal basis for action, say, "Rape a woman only when the coast is clear, you have already sired at least another child, she does not appear to be pregnant, etc." If the conditions for the action were so specific that, even if universally accepted, they would come together only rarely, and therefore would not undermine the collective reproductive success of the species, it's hard to see how the DCI could coherently reject it. Further, if the rapist used a prophylactic so that pregnancy and its burdens on the woman were not an issue, he'd seem to be that much less immoral. But surely such moral reasoning is amiss.
A second problem with the DCI is that it cuts both ways. For, if an action cannot be "morally" endorsed unless it could be applied universally for the species, then altruism seems to be morally unacceptable. No species could survive if all its members all the time acted altruistically, since, if they literally never acted for their own interests, they would become paralyzed by inaction, like Buridan's ass, and probably starve to death. More realistically, if it were only the case that nearly everyone always acted altruistically (as we are, in fact, expected to make the case!), the altruists would eventually be overtaken by the minority of "deviants" acting selfishly. The point is that if the DCI proscribes actions that would have universally negative results, then altruism is morally proscribed by the DCI. As soon as the proponent of the DCI admits there must be some 'intermediate' principle between sheer relativism and DCI-absolutism, however, she is back in the folds of traditional moral argumentation and Darwikantian ethics offers little, if any, light in the discussion.
The institution of marriage, for instance, is seen as a good in Darwikantianism because it enhances social stability and thereby promotes reproductive success. This does not, however, mean everyone can or must get married, which shows once more that there is some other domain of moral wisdom by which otherwise "natural" behaviors are deemed justifiable and not merely "mechanistically viable." If marriage is wrong in some cases, presumably because a DCI-style universalization of such cases would undermine reproductive success, then it's hard to see why rape would not be right in some cases (say, as a form of cathartic vengeance which restores the social order by taking one male down a peg by the symbolic attack of his daughter or wife). That kind of socially beneficial "ritual rape" could be applied universally, since it would only apply in certain circumstances. But again, surely such moral reasoning is flawed.
The notion of a universally applicable specific law is not incoherent; indeed, it is highly common in science. The Bode-Titius Law, for instance, is universally valid if taken in conjunction with limiting conditions (e.g. the absence of Neptune). Indeed, the whole of Newtonian physics is still scientifically, universally "true", even though it is theoretically false, when qualified thus and such. Likewise, quantum mechanics is technically deterministic according to the universal validity of the Schrödinger equations, though it is universally indeterminate in every specific case. Paradoxical, perhaps, but true. So, while rape––and altruism––would be universally unacceptable, specific cases of rape, and specific cases of altruism, would be acceptable in Darwikantianism as long as they are qualified in their particular applications.
Yet, we all know that rape is intrinsically wrong, not merely generally undesirable. How do we know this, though? Not by a vague nod to natural selection, but rather by an awareness of the intrinsic principles of right human conduct. There seems to be an important difference between universally and absolutely true (i.e. between always potentially and intrinsically valid). I will not explore that difference now, mainly because I still must ponder it, but I want to close with a syllogism that captures the point of this post.
1. Humans are intrinsically moral agents.
2. Moral action is not intrinsically derived from natural selection.
3. Therefore, the nature of humans is neither intrinsically nor exhaustively based on natural selection.
Because we can decided to be better than our instincts, we are better than the basis for our instincts.