Professor Stock is engaged with the question of whether sex should be replaced with self-identified gender in all legal, political, and social contexts, as is currently being advocated for in the UK. Maybe she is mistaken that there remain important contexts where it is sex rather than gender identity that matters. Moreover, we recognise that these matters are deeply, personally important for many people, whose views and concerns also deserve sincere respect. However, unless she and others involved in this debate are permitted to raise their concerns on this matter, engaging in open and scholarly debate without fear of harassment, so that opponents may explain why she is mistaken (if she is), the danger remains that the move to replace sex with self-identified gender will be made without adequate reflection and scrutiny.