Abstract

This paper argues that it is justified to exclude male people, and only male people, from certain spaces—sports teams, leagues, events and competitions—set aside for female athletes. More generally, it argues that it is justified to organize sports around the biological distinction between male people and female people. The first part of the paper argues that the problem of how to organize sports is not sui generis, but rather an instance of a more general philosophical problem to which the consideration of which categories are the more natural is relevant. Having offered some initial motivation for the methodological appropriateness of considerations of comparative naturalness, the paper argues that the category female enjoys greater comparative naturalness than any other in the vicinity. The paper concludes that proposals to exclude males reflect no special animus against cross-sex-identified males. This paper is based on an amicus brief submitted to the United States Supreme Court in September 2025, ahead of a landmark civil rights decision concerning the status and scope of the provisions that Title IX makes for women’s sports.