If asked whether transwomen are women, I usually response "sure." This response is typical and expected for members of the left. I believe that transwomen should be treated as women, believe they are women, should be granted protections that women receive, and so forth. The problem is that I'm not sure what my political commitments entail. The reason is that the definition of "woman" is problematic, and different definitions entail different answers to the question. For example, here are three notions of womanhood. The biological notion maintains that women are adult human females. It is not inconsistent with this definition to believe that transwomen should be treated as women, thought of as women, and so forth. However, this definition maintains that some ontological difference obtains between women and transwomen. For this reason, the biological definition is a fringe position. It is not, however, inconsistent with progressive politics. The social theorists argue that womanhood is a social construction, possible correlated with gender, but primarily defined by normative behaviors that society expects of women. On this definition, transwomen are women precisely if and when they want to or actually do behave as women. Note that this definition is dependent on a geographically and historically localized notion of womanhood. The political theorists argue that being a woman means having a certain political standpoint, and this standpoint can be enlarged to include the class of transwomen. Note that the political theory is ambiguous about whether every biologically female person who identifies as a woman is, in fact, a woman. The question is: what exactly are the commitments of someone who ways that transwomen are women? I would like to say this, because I think that (at minimum) every transwoman should be treated as though they where a woman. However, I have trouble reconciling this with various theories of womanhood. In particular, whenever I think that "transwomen are women" is true, I start substituting various theories of womanhood for "women" and come up with conflicting principles. The TLDR, then, is what is a minimal definition of "woman" such that all transwomen are women, all people who are biologically female and identity as women are women, and so forth, but everyone who does not is excluded?