The Origins of Generation

We say that one thing is generated from another, and a different thing from a different thing when we speak either of things simple or of such as are composite. That, which is simply generated therefore, I call man, and that which is not musical. But the other is not predicated of all things, for a musician is not generated from a man, but a man becomes a musician. One principle is sufficient for the purpose of being passive; if there are four principles, there will be two contourietes. If two, they are able to generate from each other, the other of the contouriete will be superfluous. At the same time however, it is impossible