Trans women are women.

Speaking as a cis woman, I want to say firmly that trans women are women.

I admit that it took me a while to understand this and I’ve had to broaden my definition of women a bit to reach that conclusion, but it seems ridiculous to define “women” as “cis women” and then say that trans women aren’t in that group (by definition). We can just as well define “women” as “people who know they are women” and trans women fit right in there.

There is no one “true” definition of a woman , as humans we choose how we categorise the world. It’s a bit like poor old Pluto: first it wasn't a planet, then it was a planet, now it's a dwarf planet, and many scientists think it would be useful to categorise it as something else instead. The lump of rock orbiting the sun hasn't changed but we define it differently according to what is most useful.

It’s most useful to broaden our definition of “women” from “assigned female at birth” to something that embraces everyone who feels themself to be a woman.

Trans women are women.

For me, that is “the truth”.