In the middle ages 211

soul, and the most inward unity of man results from

this combination; the body is primary matter,

the soul is substantial form, and each completes and

permeates the other. Therefore, our soul is not at

all in an unnatural state, when united to our body.

The soul is not to be compared, as does Plato in

the Republic, to the sea-god Glaucus, as impossible

to recognize under the grimy accretions of the sea-

shells and creeping things. On the contrary the

union of soul and body is such that the former re-

quires aid from the latter in all her activities.

The becoming of human beings, and their indi-

viduation in mankind, must also be explained by

the doctrines already exposited. The generation of

a child is the becoming of a new substance; but it

includes several stages of a specific kind, each more

perfect than the preceding. The soul is united to

the embryo only when the dispositions of the new

organism are sufficiently perfect to require union

with a human soul. Thus, in the scholastic phi-

losophy, it is really the human body, as a product

of human generation, which is the principle of indi-

viduation; it is indeed the precise reason why such

and such a soul, with its greater or lesser

treasure of potentialities, is united to such and such

a body. And although the spiritual and immortal

soul is not a product of generation, nevertheless

the parents as givers of the body to the child assume

the responsibility of fixing the potentialities of the

whole being. The soul may be compared to the

212 PHILOSOPHY AND CIVILIZATION

wine which varies in quantity according to the size

of the cup.

There is, however, one very important difference

between the human soul and the form of other be-

ings in the corporeal world. For reasons whicli

we cannot develop here, founded especially upon

the superiority of human knowledge, the human

soul is of a spiritual nature, that is, it is superior to

corporeal things and therefore immortal. Accord-

ingly, a human soul, although it constitutes a whole

with the body, is not the result of the chemical,

physical, and biological activities which explain or-

ganic generation. Aristotle had said that the in-

tellect came from without (OvpaOtv), Thomas adds:

the soul is created by God.

VII

We shall now consider, in conclusion, the place

given to the idea of God in the scholastic meta-

physics. Their natural theology, or theodicy, is

closely connected with their conception of the world.

It is drawn from the theory of change, which has

been explained above. It is intimately connected

with their whole idea of change, — but especially

with the doctrine of efficient causality.

Change, as we have seen, is the passage from

one state to another, a sort of oscillation by which

the real in potency becomes the real actually, and

so obtains a new perfection. Now the principle of

efficient causality says: No being which changes