Kitap 5
1.32
In the sphere of natural science he surpassed all other philosophers in the investigation of causes, so that even the most insignificant phenomena were explained by him. Hence the unusual number of scientific notebooks which he compiled. Like Plato he held that God was incorporeal; that his providence extended to the heavenly bodies, that he is unmoved, and that earthly events are regulated by their affinity with them (the heavenly bodies). Besides the four elements he held that there is a fifth, of which the celestial bodies are composed. Its motion is of a different kind from that of the other elements, being circular. Further, he maintained the soul to be incorporeal, defining it as the first entelechy [i.e. realization] of a natural organic body potentially possessed of life.De anima, ii. 1, 412 a 27.
