The Difference Between Animality and Rationality

Rationality is thus what is called the specific difference that distinguishes human beings from other species of animal. For our imagined things A and B to differ as species do, we would have to regard them as two species within a genus. And we then have to identify some specific difference that A has that makes it a different species - but there's no way to distinguish two things which just are existence itself. That path will not work. So consider now instead the way that two members of the same species are differentiated. The matter that makes up Socrates' body is different from that which makes up Plato's or Aristotle's body. But these other differences presuppose different parcels of matter in which the brain