PROCLUS ON THE TIMAEUS BOOK III [Tim. 31B]

If there is fire original: "πῦρ", we shall ask: from where, then, does the fire here in our world derive such a nature? For if both the celestial and terrestrial are generative of sensible light, why should not each be called fire, even if one is immaterial and the other material? I say this, as I have already mentioned previously, distinguishing "immaterial" and "material" in relation 5 to the densest kind of matter which cannot retain forms referring to the "receptacle" or prime matter that is too unstable to hold a shape, and setting apart that higher matter which always remains in its own proper form. For we shall learn that matter extends through the whole cosmos, just as the gods also say; therefore, as he proceeds, Plato will call it the "receptacle" of the universe. Just as the lights are of a certain kind, so too are the fires; and analogy shows that 10 the light from that higher realm also comes from fire.

And it must be said that Plato does not characterize fire by heat, nor by its upward motion—for these are properties of the fire found here, when it is not in its 15 proper place—but rather by its visibility. For through this quality he encompasses all fire: the divine and the mortal, the burning and the illuminating. Furthermore, the same must be said regarding earth: that earth is primarily the "solid" stereon: the quality of having three dimensions and resistance. Let no one tell me that earth received its solidity from elsewhere; rather, among sensible things, that which is most solid possesses this characteristic prior to those things which are less so. Just as that which is most hot exists prior to things that are less hot, and from this primary source the less-hot things 20 partake of that quality. In this same way, then, that which is most solid imparts its own solidity to the less solid.

If, therefore, earth is the most solid of the other elements, and the most solid is the cause in mixtures for the less solid things being solid—and not the other way around, where the lesser things cause the quality in those that possess the power preeminently—then it is surely necessary that earth is the cause of 30 solidity for the other elements, standing in opposition to fire. And if we were to take the things that appear to our senses, regarding the heavens as fiery and the earth as solid...

1 regarding "then" compare page 9, line 1. 5 regarding "densest" and "not retaining" see Timaeus 45C and 78A. 8 compare Chaldean Oracles fragment 20. 11-12 These are the opinions of Aristotle Proclus is contrasting Plato's definition of fire with Aristotle's definition based on heat and weight. 18-19 after "sensible things" manuscripts M and P insert "something." 21 "hot" (plural) in M and Q; "hot" (singular) in P. 31 "fiery" in P is perhaps correct; but compare page 11, lines 11 and 31. See also Diels, Doxographi Graeci 340.