41
But besides this, his discourse concerning the generation of the soul has a demonstration contrary to his own opinion; for he says, that the soul is generated when the infant is already brought forth, the spirit being changed by refrigeration, as by hardening. Now for the soul’s being engendered, and that after the birth, he chiefly uses this demonstration, that the children are for the most part in manners and inclinations like to their parents. Now the repugnancy of these things is evident. For it is not possible that the soul, which is not generated till after the birth, should have its inclination before the birth; or it will fall out that the soul is like before it is generated; that is, it will be in likeness, and yet not be, because it is not yet generated. But if any one says that, the likeness being bred in the tempers of the bodies, the souls are changed when they are generated, he destroys the argument of the soul’s being generated. For thus it may come to pass, that the soul, though not generated, may at its entrance into the body be changed by the mixture of likeness.
42
He says sometimes, that the air is light and mounts upwards, and sometimes, that it is neither heavy nor light. For in his Second Book of Motion he says, that the fire, being without gravity, ascends upwards, and the air like to that; the water approaching more to the earth, and the air to the fire. But in his Physical Arts he inclines to the other opinion, that the air of itself has neither gravity nor levity.