We have thus shown that God is one both in the sense of simple and in the sense of unique. To have a clear insight into the nature of his unity, we must now show that nothing else outside of God is really one, though we apply the term one to many things. No one will claim that a collective is one; but neither is an individual really one, for an individual man, for example, consists of many organs. You might think that a homogeneous and continuous elementary mass like air or water is one. But this is not true either, for everything that is corporeal is composed of matter and form. If then we set aside corporeal objects and aim to find real unity in mathematical entities like line and surface, which are not corporeal, we are met with the difficulty that line and surface are divisible, and hence potentially multiple. But neither are the simple intellectual substances, like the angels, true ones; for they are composed of their own possible existence and the necessary existence they acquire from another. The only being therefore that may be a true one is that which is not corporeal and not dependent upon another for its existence. Considering the question of unity from a different aspect, in its relation, namely, to the thing designated as one, we find that unity never forms the essence of anything called by that name; but is in every case an accident. Thus if it were the essence of man as man that he is one, there could not on the one hand be many men, and on the other there could not also at the same time be one horse, one tree, one stone. In God his unity cannot be an accident, since as simple he has no accidents. Hence his unity is his essence. And if we examine the matter carefully we find that it is a negative concept. It involves two things. First, that every other unity involves plurality in some form or another. And second that being unlike anything else, he cannot bear having other things associated with him to make the result many, as we can in the case of man. A, for example, is one; and with B, C, and D he becomes many. This is not applicable to God.[238]