Actually, I don’t much care which you say, so long as you like the general picture. Suffice it that it’s quite in the spirit of informational semantics to decide to talk like this: Homer did have the concept WATER (he had a concept that isnomologically linked to beingwater) and, of course, beingwater isn’t a mind-dependent property. So Homer had a conceptof a natural kind. But WATER wasn’t, for Homer, a concept of a natural kind as such; and for us it is. We’re locked tobeingwater via a chemical-cum-metaphysical theory, that specifies its essence, and that is quite a different mechanism ofsemantic access from the ones that Homer relied on. In particular, the two ways of locking to water support quitedifferent counterfactuals. This shows up (inter alia) in the notorious thought experiments about Twin-Earth: we thinkthat XYZ wouldn’t be water; Homer wouldn’t have understood the question.
But an entirely informational and atomistic semantics can also do justice to the intuition that Homer had the same WATER concept as ours. All the metaphysics of concept possession requires, of our concept WATER or Homer’s, isbeing locked to water. If you are locked to water our way, you have the concept WATER as a natural kind concept; ifyou are locked to concept WATER Homer’s way, you have the concept WATER, but not as a natural kind concept.But, on a perfectly natural way of counting, if you are locked to water either way, you have the concept WATER. (Isuppose that God is locked to being water in still a third way; one that holds in every metaphysically possible world butisn’t theory-mediated. That’s OK with informational semantics; God can have the concept WATER too. He can‘t,however, have the pretheoretic concept WATER; the one that’s locked to water only by its superficial signs. Nobody’sPerfect.)
If you’re lucky, you can have concepts of natural kinds on the cheap. Homer maybe didn’t need much to get WATER locked to water, maybe all he needed was innate detectors for the phenomenological properties which, in point ofnomological necessity, water has in all the worlds near to him (and us). But, of course, you only get what you pay for:Homer didn’t have the concept of water as a natural kind concept. To have that, he would need to have been locked tothe essence of water via the essence of water; that is, in a way that doesn’t depend on water’s superficial signs. Probably,de facto, all such lockings (except God’s) are theory-mediated; indeed, they are perhaps all metatheory-mediated; theymay well depend, de facto, on having not just concepts of natural kinds, but also the concepts NATURAL KIND andHIDDEN ESSENCE. Which nobody did until quite recently.
But I want to emphasize what I take to be a main moral of the discussion: the ‘de facto’ matters. Just as IA says there are no concepts the possession of which is metaphysically necessary for having WATER (except WATER), so I’d like itto say that there are no concepts the possession of which is metaphysically necessary for having WATER as a naturalkind concept (except WATER); all that’s required is being locked to water in a way that doesn’t depend on its superficialsigns. But, of course, metaphysically necessary is one thing, on the cards is quite another. I’m quite prepared to believethat, de facto, until we had (indeed, had more or less self-consciously), the concepts that cluster around NATURALKIND, there was probably no way that we could link to WATER except the sort of way that Homer did and childrenand animals do; viz. via water’s metaphysically accidental but nomologically necessary properties. But now we have atheory that tells us what water is, and we are linked to water via our acceptance of that theory. Science discoversessences, and doing science thereby links us to natural kinds as such.
I think, by the way, that the ethological analogies play out quite nicely on this sort of analysis. It’s natural and handy and, for most purposes harmless, to say that ducklings have the concept MOTHER DUCK innately; that malesticklebacks have the concept CONSPECIFIC RIVAL innately, and so on.Jean-marc pizano