- * *Claim*: Trans people are born with a brain-restricted intersex condition such that their psychology is much more typical of the other physiological sex: the proverbial "woman trapped in a man's body" (respectively "man ... woman's") trope is basically accurate.
- * *Claim*: The medical interventions undergone during transition—hormone replacement surgery, sex reassignment surgery, _&c._—are effective at inducing the phenotype of the other physiological sex: physically, transitioning _works_.
- * *Claim*: Gender is mostly attributed on the basis of apparent secondary sex characteristics: in most situations, most people don't care about predicting the configuration of someone's genitalia at birth or whether they have a Y chromosome.
- * *Conclusion*: Trans people can legitimately be said to belong to their stated gender, using the _same_ criteria people usually use to decide such things.
+Well, no. But the point is that this is an _empirical_ argument for why successfully socially-transitioned trans people fit into _existing_ concepts of gender, _not_ a redefinition of top-20 nouns by fiat in order to avoid hurting someone's feelings. It works _because_ and _to the extent that_ transitioning actually works. To the extent that this fails to be true of self-identified trans people or some subset thereof—for example, insofar as physical transition _isn't_ always effective, or insofar as people _do_ have legitimate use-cases for biological-sex classifications that aren't "fooled" by hormones and surgery—then the conclusion is correspondingly weakened.