His general ideas Aristotle[75] shortly sums up thus: “To the three elements, fire, air, and water, each of which was in turn considered as the principle from which everything proceeded, Empedocles added the Earth as the fourth corporeal element, saying that it is these which always remain the same, never becoming, but being united and separated as the more or the less, combining into one and coming out of one.” Carbon, metal, &c., are not something existing in and for itself which remains constant and never becomes; thus nothing metaphysical is signified by them. But with Empedocles this undoubtedly is the case: every particular thing arises through some kind of union of the four. These four elements, to our ordinary idea, are not so many sensuous things if we consider them as universal elements; for, looked at sensuously, there are various other sensuous things. All that is organic, for example, is of another kind; and, further, earth as one, as simple, pure earth, does not exist, for it is in manifold determinateness. In the idea of four elements we have the elevation of sensuous ideas into thought. Aristotle further says in reference to the abstract Notion of their relation to one another (Met. I. 4), that Empedocles did not only require the four elements as principles, but also Friendship and Strife, which we have already met with in Heraclitus; it is at once evident that these are of another kind, because they are, properly speaking, universal. He has the four natural elements as the real, and friendship and strife as the ideal principles, so that six elements, of which Sextus[76] often speaks, make their appearance in lines that Aristotle (Met. II. 4) and Sextus (adv. Math. VII. 92) have preserved:— “With the earth, we see the earth, with water, water, With air, heavenly air, with fire, eternal fire, With love, love is seen, and strife with sorrowful strife.” Through our participation in them they become for us. There we have the idea that spirit, the soul, is itself the unity, the very totality of elements, in which the principle of earth relates to earth, water to water, love to love, &c.[77] In seeing fire, the fire is in us for whom objective fire is, and so on.