William M. Briggs makes the same point I recently made. In order for language to work, terms need to have referents. When a “man” claims to be a “woman,” he has to be referring to some objectively identifiable concept of “woman.” But that means that “woman” is more than just a state of mind. Says Briggs:
He must be referring to a biological woman and not a “gendered” woman, else his identification falls into infinite regress. Think about it. If our first man thinks he is a woman based on his notion of a second man’s “gendered” woman status, that second man must have got his notion of woman from actual biology, or he must have got it from a third man’s “gendered” woman status, and so on. Somewhere down the line there necessarily had to be a biological notion of woman.
Read more: http://wmbriggs.com/post/19666/