Chapter Xi. of Causes.

A cause is that by which anything is produced, or by which anything is effected.

Plato gives this triple division of causes,--the material, the efficient, and the final cause; the principal cause he judges to be the efficient, which is the mind and intellect.

Pythagoras and Aristotle judge the first causes are incorporeal beings, but those that are causes by accident or participation become corporeal substances; by this means the world is corporeal.

The Stoics grant that all causes are corporeal, inasmuch as they are physical.