Apartheid of Sex: A Manifesto on the Freedom of Gender
Why this book?
Although I endorse Rothblatt's ideal of a sex-irrelevant society, I think he fails to fully comprehend the subordination by sex that females currently experience. And if he hadn't been so rich (like Jenner), he might not have voluntarily become a member of that sexed underclass. (I suspect his money has largely insulated him from the negative effects of being perceived as a woman.) That said, this 1995 book is a pioneering classic. (Though I think the subtitle should have been "A Manifesto on the Freedom from Gender" — not " A Manifesto on the Freedom of Gender".)