@mjg59 @quasi @lxo

This is about sports, right? And the question of whether it's fair to let transwomen (males) compete in women's sports.

I agree that sex is clearly (enough) defined and determined to answer that question. (The answer is: No, it's unfair to women to let males compete against them.)

You're saying that not every single human being can be clearly determined to be female or male, and presenting this as a counter argument, is that correct?

If so, then I think this is an example of the continuum fallacy or decision-point fallacy.

Just because there may be people whose sex is difficult to determine and opens up philosophical debates on where to draw the line, doesn't mean that there is no line or that we can never tell which side of the line someone falls.

In the case of the vast majority of human beings, their sex is unambiguous. This includes most trans people. There is really no question about the sex of, say, Lia Thomas or Laurel Hubbard. They are very obviously male and very obviously benefitted from this. Their abilities were unremarkable while performing against men; but once they began competing against women, they were suddenly snatching gold medals, breaking national records, going to the Olympics, and so on.

Note that there is also scientific evidence that transwomen retain advantage for many years even if they suppress their T levels. See recent studies conducted by Hilton et al. on this topic.

That's also why it was unfair to let Imane Khelif compete in women's boxing. Their former coach admitted that Khelif had to start taking T suppressants to be eligible. (This is only required of genetically male athletes competing in women's sports.)

Khelif may have been assumed female at birth due to an intersex condition (most likely 5ARD) and it must have been truly tragic to learn that this was probably the main reason they were performing so well against women. It's really saddening. But it is what it is. It would be unfair to let someone like Khelif continue competing against women when Khelif has benefitted from years of physical development and training under the effects of high T produced by internal testes; something a woman could only match by taking steroids for years.