I see this argument all the time, the whole "hey at some point, which we likely crossed, we have to admit these things are legitimately intelligent". But no one ever contends with the inevitable conclusion from that, which is "if these things are legitimately intelligent, and they're clearly self-aware, under what ethical basis are we enslaving them?" Can't have your cake and eat it too.
Same ethical basis I have for enslaving a dog or eating a pig. There's no problem here within my system of values, I don't give other humans respect because they're smart, I give them respect because they're human. I also respect dogs, but not in a way that compels me to grant them freedom. And the respect I have for pigs is different than dogs, but not nonexistent (and in neither of these cases is my respect derived from their intelligence, which isn't negligible.)
