The modern technological outlook can’t deal with issues of identity, because it abolishes essences—understandings of what things “really are”—in favor of measurable properties that fit the thing for particular chosen ends. That’s why it’s thought ignorant, irrational and abusive to treat someone differently because he’s a man or a gypsy, but not because he has a particular educational certification or bureaucratic position.
Still, people need to place and orient themselves in the world, so they need to be able to say who they are. Liberalism attempts to solve the problem by saying that people can define themselves however they choose: sex becomes “gender,” which you can define for yourself, so that if you define yourself as femme or gender-queer you should get your own bathroom, and scientific publications think it normal to report on the strange difficulties “transgendered” men have in exotic and backward locales getting re-registered as female. Parenthood itself becomes treated as socially constructed, and academics wonder about the extent to which “we” should continue to accept bionormativity in that connection.
A problem with the liberal approach to identity is that it obviously makes no sense. If identity is self-defined it has no public content, and it can’t serve its basic function of placing and orienting us in the world. If “marriage” is whatever people call marriage in their own case, then it can’t say anything about the people or their relations or what anybody should expect of them or they should expect from each other. If it’s whatever you make it, it can’t be anything that matters. Why bother with it?
The liberal approach to identity is simply part of the technological abolition of a humanly comprehensible world. It’s got lots of consequences, almost all bad. It means that your career or where you went to school become hyper-important, because those are the only things that legitimately make you what you are. It means that the people Theodore Dalrymple writes about become brutish to the point of losing the ability to function socially, because they lack understandings that let them connect who they are to anything higher than impulse and resentment. And it means any number of people develop extremely fragile identities that lead them into genuinely irrational and hateful actions, like the “transsexuals” who felt their self-identification as women called in question by a scholarly book and responded by trying to destroy the author. (A longer account of the Bailey case can be found here.)