Empedocles also speaks of the process of these elements, but he did not comprehend it further; the point to be remarked is that he represented their unity as a combination. In this synthetic union, which is a superficial relation devoid of Notion, being partly related and partly unrelated, the contradiction necessarily results that at one time the unity of elements is established and at another, their separation: the unity is not the universal unity in which they are moments, being even in their diversity one, and in their unity different, for these two moments, unity and diversity, fall asunder, and union and separation are quite indeterminate relationships. Empedocles says in the first book of his poem on Nature, as given by Sturz (p. 517, v. 106-109): “There is no such thing as a Nature, only a combination and separation of what is combined; it is merely called Nature by men.” That is to say, that which constitutes anything, as being its elements or parts, is not as yet called its nature, but only its determinate unity. For example, the nature of an animal is its constant and real determinateness, its kind, its universality, which is simple. But Empedocles does away with nature in this sense, for every thing, according to him, is the combination of simple elements, and thus not in itself the universal, simple and true: this is not what is signified by us when we speak of nature. Now this nature in which a thing moves in accordance with its own end, Aristotle (De gen. et corr. II. 6) misses in Empedocles; in later times this conception was still further lost. Because the elements were thus existent simply in themselves, there was, properly speaking, no process established in them, for in process they are only vanishing moments, and not existent in themselves. Being thus implicit, they must have been unchangeable, or they could not constitute themselves into a unity; for in the one their subsistence, or their implicit existence would be destroyed. But because Empedocles says that things subsist from these elements, he immediately establishes their unity. These are the principal points in Empedocles’ philosophy. I will quote the remarks that Aristotle (Met. I. 4) makes in this regard.