Today I want to look at “essentialism” as a possible alternative to the use of conventions. And then, toward the end of the post, I’ll briefly consider some other possible alternatives.
With today’s post, I will continue to use the hypothetical that I introduced in my previous post. That is to say, I will assume that small animals are classified into two species, which I shall call “cats” and “dogs”. There is no assumption that I am talking about what we usually call “cats” and “dogs”. I’m just borrowing those names for convenience.
Essentialism
The idea of essentialism, is that what makes an animal a cat is that it contains the essence of cathood. Likewise, what makes an animal a dog is that it has the essence of doghood. The name “essentialism” comes from this reference to essences.
The Heretical Philosopher 