ern mind, it would seem that the cause of a change must be a previous change, and that, if the
universe were ever wholly static, it would remain so eternally. To understand what Aristotle
means, we must take account of what he says about causes. There are, according to him, four
kinds of causes, which were called, respectively, material, formal, efficient, and final. Let us take
again the man who is making a statue. The material cause of the statue is the marble, the formal
cause is the essence of the statue to be produced, the efficient cause is the contact of the chisel
with the marble, and the final cause is the end that the sculptor has in view. In modern
terminology, the word "cause" would be confined to the efficient cause. The unmoved mover may
be regarded as a final cause: it supplies a purpose for change, which is essentially an evolution
towards likeness with God.
I said that Aristotle was not by temperament deeply religious, but this is only partly true. One
could, perhaps, interpret one aspect of his religion, somewhat freely, as follows:
God exists eternally, as pure thought, happiness, complete selffulfilment, without any unrealized
purposes. The sensible world, on the contrary, is imperfect, but it has life, desire, thought of an
imperfect kind, and aspiration. All living things are in a greater or less degree aware of God, and
are moved to action by admiration and love of God. Thus God is the final cause of all activity.
Change consists in giving form to matter, but, where sensible things are concerned, a substratum
of matter always remains. Only God consists of form without matter. The world is continually
evolving towards a greater degree of form, and thus becoming progressively more like God. But
the process cannot be completed, because matter cannot be wholly eliminated. This is a religion of
progress and evolution, for God's static perfection moves the world only through the love that
finite beings feel for Him. Plato was mathematical, Aristotle was biological; this accounts for the
differences in their religions.
This would, however, be a one-sided view of Aristotle's religion; he has also the Greek love of
static perfection and preference for contemplation rather than action. His doctrine of the soul
illustrates this aspect of his philosophy.
Whether Aristotle taught immortality in any form, or not, was a vexed question among
commentators. Averroes, who held that he did not, had followers in Christian countries, of whom
the more