"I think the issue of sex-change for males is no longer one in which much can be said for the other side. But I have learned from the experience that the toughest challenge is trying to gain agreement to seek empirical evidence for opinions about sex and sexual behavior, even when the opinions seem on their face unreasonable. One might expect that those who claim that sexual identity has no biological or physical basis would bring forth more evidence to persuade others. But as I’ve learned, there is a deep prejudice in favor of the idea that nature is totally malleable. Without any fixed position on what is given in human nature, any manipulation of it can be defended as legitimate. A practice that appears to give people what they want—and what some of them are prepared to clamor for—turns out to be difficult to combat with ordinary professional experience and wisdom."