I am composed of the formal and the material; and neither of them will perish into nonexistence, as neither of them came into existence out of nonexistence. Every part of me then will be reduced by change into some part of the universe, and that again will change into another part of the universe, and so on forever. And by consequence of such a change I too exist, and those who begot me, and so on forever in the other direction. For nothing hinders us from saying so, even if the universe is administered according to definite periods of revolution.

Reason and the reasoning art [philosophy] are powers which are sufficient for themselves and for their own works. They move then from a first principle which is their own, and they make their way to the end which is proposed to them; and this is the reason why such acts are named catorthoseis or right acts, which word signifies that they proceed by the right road.