Many feminists (e.g. T. Bettcher and B. R. George) argue for a principle of first person authority (FPA) about gender, i.e. that we should (at least) not disavow people's gender self-categorisations. However, there is a feminist tradition resistant to FPA about gender, which I call "radical feminism”. Feminists in this tradition define gender-categories via biological sex, thus denying non-binary and trans self-identifications. Using a taxonomy by B. R. George, I begin to demystify the concept of gender. We are also able (...) to use the taxonomy to model various feminist approaches. It becomes easier to see how conceptualisations ofgender which allow for FPA often do not allow for understanding female subjugation as being rooted in reproductive biology. I put forward a conceptual scheme: radical FPA feminism. If we accept FPA, but also radical feminist concerns, radical FPA feminism is an attractive way of conceptualising gender. (shrink)