> Anyone who wishes to prove otherwise is welcome to become a dog.
Saying that there's no essential dog-nature does not inherently imply that one can become a dog.
> (virtually everyone)
Yes, Plato and Aristotle were essentialists, and you can't possibly over-state their influence on Western thought. But, I would argue that your 'everyone' includes many non-philosphers, who haven't necessarily considered this problem in the depth that philosophers have. That doesn't mean that essentialism is disproven or anything! But rightfully, in my mind anyway, a number of schools of thought take issue with it, just like any other position.
That said, actually, it depends on who you're talking to.
> that's seems a strawman definition in this context
It's not! That's the problem itself: you're absolutely right that defining what is a chair and what is human is very difficult.
Saying that there's no essential dog-nature does not inherently imply that one can become a dog.
> (virtually everyone)
Yes, Plato and Aristotle were essentialists, and you can't possibly over-state their influence on Western thought. But, I would argue that your 'everyone' includes many non-philosphers, who haven't necessarily considered this problem in the depth that philosophers have. That doesn't mean that essentialism is disproven or anything! But rightfully, in my mind anyway, a number of schools of thought take issue with it, just like any other position.
That said, actually, it depends on who you're talking to.
> that's seems a strawman definition in this context
It's not! That's the problem itself: you're absolutely right that defining what is a chair and what is human is very difficult.