What is Sex?
Semantics of Sex
Why Are Some Transwomen Women?

Sex is a function from a bimodal N-dimensional attractor field cluster family concept to a set of biocultural facts.

Let’s unpack.
1) Bimodal – Male Female
2) N-dimensional – several characteristics are sex determinative, none is essential. Same as religion. The concept is defined by an ostensive pointing of a cluster of concepts, and if you have enough of those concepts, you qualify as a category member.
3) Attractor – no one is perfectly male or female, but a dot in a large field where these two attractors are where the vast majority of people fall. Some fall in between, some fall past, hypermasculine and hyperfeminine.
4) Field – you can think of it as a scalar field or a vector field, but the point is that sex is a little fluid over time, for example, when hot girls cut their hair, they get far away from the female cluster, so they are tensioned towards the male attractor.
5) cluster family – that’s just how analytic philosophy calls these concepts that you have to be like 70% of 100 characteristics to belong.
6) To a set of cultural facts – some part of sex is performance, drag, societal perception, and the understanding of others. Sex is not exhaustively local. For example a person could be exactly in the middle of male female, having half of the determinations of each side, biologically, but they, twins separated at birth, went to live in two societies, one in Polite Lovinland, and one in Scarcity Island. The one living in Polite Lovingland identifies as male, and that rich society of polite people decided to treat them as male, since the cost to society is low, and the gains for the person are large. The other is living through 3 civil wars and two famines, not to mention diphtheria, tetanus, things are tough. That society has no time to be polite, it needs rigid rules to survive, to reproduce, to self-sustain. Despite identifying as male, that society uses only reproduction to label people, because they need munition, soldiers, and food, now. The enemy is at the gates. So in that society, that person is female.

So that’s what sex is, metaphysically.
A function from an N-dimensional bimodal cluster family concept field to a series of normative and cultural considerations.

Quoting the unforgetful David Lewis, the most accomplished analytic philosopher in history, who single-handedly published more than all women combined:
“I promised simplicity; I deliver functions from functions from functions to functions to functions from functions to functions.” General Semantics – 1970 pg 29

I wish the world today could process information at the level David Lewis was capable of.

Anyway, I know that compared to Lewis’s analysis, I simplified things a lot here, for a real definition of sex I’d have to talk about modality, primary and secondary intensions, and so on.