This is a silly, sensationalist book that attracted a lot of attention when it was first published because of its clearly prejudiced portrayal of transgendered people and its promotion of the so-called theory of "autogynephilia". The latter is a scientific hypothesis developed in the 1990s by Canadian psychologist Ray Blanchard, whose central premise is the idea that many biological males who undergo gender reassignment do so because of their sexual attraction to a fantasised image of themselves as women, which Blanchard classifies as a "paraphilia". Blanchard's theory has been heavily criticised because it draws a rigid distinction between transsexuals with an exclusively homosexual orientation and those with a predominantly homosexual, bisexual or heterosexual orientation, and then attributes completely different motives to the two groups. This approach is conceptually flawed as it seeks to classify in binary terms what is clearly, from an empirical perspective, a spectrum of sexual behaviours and feelings. Faced with this difficulty, Bailey and Blanchard accuse transsexuals who claim not to fit neatly into their two categories of being "in denial" about their motives. Thus insulated from criticism, the theory becomes a closed system which is incapable of being falsified - an essential test of any scientific hypothesis.
Leaving aside this somewhat philosophical point, there is in fact a much simpler explanation of why M-T-F transsexuals fantasise that they are women. (In science, simpler explanations are always to be preferred over more complex ones if they fit the observed evidence.) They do so because they are gender dysphoric, which is simply another way of saying that they experience a sharp incongruity between their physical sex and their mental image of themselves as women, usually dating from childhood or early adolescence. This has always been the essence of the M-T-F transsexual experience, and it does not require an explanation based on sexual arousal patterns. In fact, transsexuals' fantasies are often remarkably ordinary, apart from the inversion of their gender identity. They bear no resemblance to the genuine paraphilias that involve unusual fetish objects which were catalogued so thoroughly by Professor John Money in the 1960s. So the whole concept of autogynephilia is very shaky from a scientific standpoint.
The problem with Bailey's book is that he treats autogynephilia as established scientific fact, rather than an interesting hypothesis, and then uses it to construct a sexually driven model of transsexuality which very few transgender people can relate to. When trans people point out that he is mis-representing them, he simply accuses them of dishonesty - hardly a sound research method. Moreover, the book positively oozes with prejudice against gay and transgender people. It is written from a perspective of presumed superiority, the overall attitude being that this is a community of self-deluded freaks. The reality is that most transgender people are highly capable, productive members of society. The only thing holding them back is society's insistence on a highly rigid, binary gender divide that has no foundation in biological reality. Bailey's insistence that they are destined always to be men is symptomatic of this simplistic binary approach.