A simpler example: imagine that beavers slap their tail when there’s danger, and beavers flee when they hear another beaver slap its tail.
The idea of teleosemantics is an evolutionary sort of semantics.
Acknowledge language use is normative (make distinction between correct and incorrect use).
You have to draw the distinction in the way that’s compatible with any degree of badness of the participants actually following the rules.
We look at a reproductive family, the normal explanation (a tehcnial term) of tail slapping is that, in the evolutionary history, lives were saved by it.
When the explanation of the persistence of tail slapping turns on particular events in the past where things worked well that way (expressed in terms of counterfactuals - no tail slap, then species dies out), then we can say its part of the proper function (technical term) to perform that behavior.
This solves some puzzle cases: it allows us to say the proper function of sperm is to fertilize eggs even if a vanishingly small fraction of them actually do (because if they hadn’t fertilized eggs in the past, there wouldn’t be sperm now).
Well, this is the form of explanation for semantics in general. Because the same thing can happen when the reproductive families are uses of words.
You can explain why we use the word ‘Aristotle’, as we do, if has having a proper function of, in the end, referring to Aristotle, because if people in the past had not used it, in particular ways, we wouldn’t be using it today.
And similarly, for predicates, and so on.
These are not biological norms. But we can understand words as having proper functions in the same sense in which even in the merely biological case, we can understand things as having proper functions. And we can understand them as having proper signaling functions.
So, there’s a proper function for producing these things and a proper function for receiving them.
There, the analogy of the of the tail slaps is a good one.
In order to understand semantic content, we don’t need to use any principles of explanation that aren’t already intelligible.