History of Western Philosophy - Bertrand Russell [100]
The doctrine of matter and form in Aristotle is connected with the distinction of potentiality and actuality. Bare matter is conceived as a potentiality of form; all change is what we should call 'evolution', in the sense that after the change the thing in question has more form than before. That which has more form is considered to be more 'actual'. God is pure form and pure actuality; in Him, therefore, there can be no change. It will be seen that this doctrine is optimistic and teleological: the universe and everything in it is developing towards something continually better than what went before.
The concept of potentiality is convenient in some connections, provided it is so used that we can translate our statements into a form in which the concept is absent. 'A block of marble is a potential statue' means 'from a
block of marble, by suitable acts, a statue is produced.' But when potentiality is used as a fundamental and irreducible concept, it always conceals confusion of thought. Aristotle's use of it is one of the bad points in his system.
Aristotle's theology is interesting, and closely connected with the rest of his metaphysics—indeed, 'theology' is one of his names for what we call 'metaphysics'. (The book which we know under that name was not so called by him.)
There are, he says, three kinds of substances: those that are sensible and perishable, those that are sensible but not perishable, and those that are neither sensible nor perishable. The first class includes plants and animals, the second includes the heavenly bodies (which Aristotle believed to undergo no change except motion), the third includes the rational soul in man, and also God.
The main argument for God is the First Cause: there must be something which originates motion, and this something must itself be unmoved, and must be eternal, substance, and actuality. The object of desire and the object of thought, Aristotle says, cause movement in this way, without themselves being in motion. So God produces motion by being loved, whereas every other cause of motion works by being itself in motion (like a billiard ball). God is pure thought; for thought is what is best. 'Life also belongs to God; for the actuality of thought is life, and God is that actuality; and God's self-dependent actuality is life most good and eternal. We say therefore that God is a living being, eternal, most good, so that life and duration continuous and eternal belong to God; for this is God' (1072b).
'It is clear then from what has been said that there is a substance which is eternal and unmovable and separate from sensible things. It has been shown that this substance cannot have any magnitude, but is without parts and indivisible…. But it has also been shown that it is impassive and unalterable; for all the other changes are posterior to change of place' (1073a).
God does not have the attributes of a Christian Providence, for it would derogate from His perfection to think about anything except what is perfect, i.e. Himself. 'It must be of itself that the divine thought thinks (since it is the most excellent of things), and its thinking is a thinking on thinking' (1074b). We must infer that God does not know of the existence of our sublunary world. Aristotle, like Spinoza, holds that, while men must love God, it is impossible that God should love men.
God is not definable as 'the unmoved mover'. On the contrary, astronomical considerations lead to the conclusion that there are either forty-seven or fifty-five unmoved movers (1074a). The relation of these to God is not made clear; indeed the natural interpretation would be that there are forty-seven or fifty-five gods. For after one of the above passages on God Aristotle proceeds: 'We must not ignore the question whether we are to suppose one such substance or more than one,' and at once embarks upon the argument that leads to the forty-seven or fifty-five unmoved movers.
The conception of an unmoved mover is a difficult one.