Atheism and Theism 131undergoing modification, and in the narrower sense of not being subject to
emotion. This reasoning also bears upon the first of the two point’s men-
tioned above, viz. the idea of divine simplicity. One reason why the activity
of the first cause cannot derive from internal changes is that such an agent
can have no moving (i.e. changing) parts; indeed it can have no parts at all.
Once again it is important to be clear as to the nature of this claim. The
doctrine of divine simplicity is not the thesis that God is relatively uncom-
plicated. Ordinarily when we describe something as ‘simple’ this is to contrast
it in point of degree of complexity with other things. But God is not simple in
this sense; rather the relevant contrast is between that which is composite and
that which is not. God can have no physical parts or else he would belong to
the natural order and hence give rise to the same sorts of questions that
initiate the five ways. Equally, he can have no metaphysical parts; that is to
say God cannot coherently be thought of as composed of such elements as
substance and attribute, or form and matter.
In the case of things in the world there is a distinction to be drawn
between features or attributes and that in which they inhere. On the one
hand there is greyness, roughness and solidity, and on the other there is the
subject of these, namely the stone. These features are of kinds that are or can
be instantiated by other things. The stone, however, is a particular or indi-
vidual and is not repeatable, though there may be others qualitatively indis-
tinguishable from it. Moreover, while the stone may change its colour or
become smooth, these sorts of changes in its attributes are different in kind
from others, such as its being crushed, which would be equivalent to its
destruction. Indeed, we can describe destruction philosophically as ‘change in
respect of identity-constituting essential properties’.
Similarly, in order to make sense of particular changes, and of change as
such, we need to identify a medium of change. There are various candidates
for this but in keeping with the Aristotelian–Thomistic orientation of
the present discussion let me introduce a metaphysical understanding of the
notion of matter. In everyday parlance, when we speak of ‘matter’ we have in
mind more or less solid stuffs like wood, plastic, stone or metal; or possibly the
microphysical particles investigated by science. Since the Greeks, however,
there has been another, philosophical, notion of matter which is correlative
to the idea of form. In this sense every natural thing is a metaphysical
composite of formal and material aspects. In other words everything is a
combination of a set of one or more characteristics (essential and inessential)
and, so to speak, an ‘occasion’ or ‘place’ of their instantiation. Further, the
locus for a set of features or forms involves a series of possibilities. So, for
example, the apple on the desk has a range of characteristics some of which
can and others of which cannot change without its being destroyed. But these
forms – colour, shape, texture, and so on – may be shared by another apple