=4. Aristotle’s Conception of Matter.= The other and lower limit of Aristotle’s dualism is Matter, “first Matter,” as Aristotle called it. In itself it is wholly unformed and mere possibility. But it is unlike pure Form in this respect,――it never exists in itself. God exists apart from Matter, but since Matter is mere possibility, Matter never exists apart from Form. Matter has a double character. On the one hand Matter is that which as an accessory cause makes the world of phenomena possible; on the other hand it is the source of the lawless and purposeless in nature. Through its seeking to be formed it makes the presentation of the Idea possible, and yet it stands as a deterrent principle to the full presentation of the Form. On the one hand it is the _sine qua non_ of physical nature, shows itself in real physical effects, and is the basis of mechanical causation, motion, and impact. On the other hand it stands in the way of the Forms actualizing themselves fully, and it prevents the universe from perfecting itself as God is perfect. While Matter is not an indifferent negative (as in Plato’s teaching), but the necessary substratum of corporeal things, it is however the indeterminate, and the ground of the accidental and purposeless in nature. Matter is the infinite and unlimited, and is the source of unusual phenomena, like monstrosities and abortions. Both fate and accident are due to the retarding influence of Matter, because it obstructs the successful working out of Form. Quite in accord with Greek thought, Aristotle conceived necessity and chance to be fundamentally the same, and the Greek custom of drawing lots shows the universality of the notion.