“But,” continues Posner—I didn’t know there were any “buts” when it comes to rape—”some rapists derive extra pleasure from the fact that the woman has not consented. For these rapists, there is no market substitute … and it could be argued therefore that, for them, rape is not a purely coercive transfer and should not be punished if the pleasure to the rapist (as measured by what he would be willing to pay—though not to the victim—for the right to rape) exceeds the victim’s physical and emotional pain. There are practical objections [No, really? Practical objections to rape?] … [b]ut the fact that any sort of rape license is even thinkable [what kind of bigoted rape-o-phobe would suggest otherwise?] … is a limitation on the usefulness of that theory.
“What generates the possibility of a rape license,” he persists (hold off, fellas, they’re not available yet), “is the fact that the rapist’s utility is weighted the same as his victim’s utility. If it were given a zero weight in the calculus of costs and benefits, a rape license could not be efficient. The only persuasive basis for such a weighting, however, would be a moral principle different from efficiency.”
And herein lies the rub. We all know what Posner thinks about “moral principles.” He’s a moral relativist. There are no moral principles, most especially no “traditional” moral principles. I mean, “How can tradition be a reason for anything?”