Finally there is the real and actual one. This is something that does not change or multiply; that cannot be described by any material attribute, that is not subject to generation and decay; that does not move and is not similar to anything. It is one in all respects and the cause of multiplicity. It has no beginning or end, for that which has is subject to change, and change is opposed to unity, the thing being different before and after the change. For the same reason the real one does not resemble anything, for resemblance is an accident in the resembling thing, and to be possessed of accidents is to be multiple. Hence the true one resembles nothing. Its oneness is no accident in it, for it is a purely negative term in this application. It means not multiple.[116] We have now shown that there is a creator who is one, and on the other hand we have analyzed the various meanings of the term one, the last of which is the most real and the purest. It remains now to show that this pure one is identical with the one creator. This can be proved in the following way. The world being everywhere composite contains the one as well as the many--unity of composition, plurality of the parts composed. As unity is prior by nature to plurality, and causes do not run on to infinity (see above, p. 87), the causes of the world's unity and multiplicity cannot be again unity and multiplicity of the same kind forever. Hence as multiplicity cannot be the first, it must be unity--the absolute and true unity before which there is no other, and in which there is no manner of multiplicity. But God is the one cause of the universe, as we have shown, hence God and this true unity are the same. We can show this also in another way. Whatever is an accidental attribute in one thing is an essential element in some other thing. Thus heat is an accidental attribute in hot water. For water may lose its heat and remain water as before. It is different with fire. Fire cannot lose its heat without ceasing to be fire. Hence heat in fire is an essential element; and it is from fire that hot water and all other hot things receive their heat. The same thing applies to the attribute of unity. It is accidental in all creatures. They are called one because they combine a number of elements in one group or concept. But they are really multiple since they are liable to change and division and motion, and so on. Hence there must be something in which unity is essential, and which is the cause of whatsoever unity all other things possess. But God is the cause of the universe, hence he is this true and absolute unity, and all change and accident and multiplicity are foreign to him.[117]