Greek Texts & Translations

The nature of “heavy” and “light” would be shown most clearly if, along with them, we examined also the nature of “above” and “below,” as they are called. That there really exist two distinct and totally opposite regions, each of which occupies one-half of the Universe—the one termed “below,” towards which move all things possessing any bodily mass, and the other “above,” towards which everything goes against its will,— 62dthis is a wholly erroneous supposition ^note For inasmuch as the whole Heaven is spherical, all its outermost parts, being equally distant from the center, must really be “outermost” in a similar degree; and one must conceive of the center, which is distant from all the outermost parts by the same measures, as being opposite to them all. Seeing, then, that the Cosmos is actually of this nature, which of the bodies mentioned can one set “above” or “below” without incurring justly the charge of applying a wholly unsuitable name? For its central region cannot rightly be termed either “above” or “below,” but just “central”; while its circumference neither is central nor has it any one part more divergent than another from the center or any of its opposite parts. But to that which is in all ways uniform, what opposite names can we suppose are rightly applicable, or in what sense? For suppose there were a solid body evenly-balanced at the center of the universe, 63ait would never be carried away to the extremities because of their uniformity in all respects; nay, even were a man to travel round it in a circle he would often call the same part of it both “above” and “below,” according as he stood now at one pole, now at the opposite. ^note For seeing that the Whole is, as we said just now, spherical, the assertion that it has one region “above” and one “below” does not become a man of sense.

Now the origin of these names and their true meaning which accounts for our habit of making these verbal distinctions even about the whole Heaven, 63bwe must determine on the basis of the following principles. Suppose that a man were to take his stand in that region of the Universe in which the substance of fire has its special abode, and where also that substance to which it flies is collected in largest bulk; and suppose that, having the power to do so, he were to separate portions of the fire and weigh them, putting them on scales and lifting the balance and pulling the fire by force into the dissimilar air, it is obvious that he will force the smaller mass more easily than the larger. 63cFor if two masses are lifted up simultaneously by a single effort, the smaller will necessarily yield more and the larger less, owing to its resistance, to the force exerted; and the large mass will be said to be “heavy” and moving “down,” the small light and moving “up.” Now this is just what we ought to detect ourselves doing in our region here. Standing on the earth and detaching various earthy substances, and sometimes pure earth, we pull them into the dissimilar air by force and against nature, since both these kinds cleave to their own kindred; 63dand the smaller mass yields more easily, and follows first, as we force it into the dissimilar kind; wherefore we name it “light,” and the region to which we force it “above”; and the conditions opposite thereto we name “heavy” and “below.” Thus, these must necessarily differ in their mutual relations, because the main masses of the Kinds occupy regions opposite to one another; for when we compare what is light in one region with what is light in the opposite region, and the heavy with the heavy, the “below” with the below, 63eand the” above with the above, we shall discover that these all become and are opposite and oblique and in every way different in their mutual relations. There is, however, this one fact to be noticed about them all, that it is the passage of each kind to its kindred mass which makes the moving body heavy, and the region to which such a body moves “below”; while the opposite conditions produce the contrary results. ^note Let this, then, stand as our account of the causes of these conditions.

Of “smoothness” and “roughness” anyone might be able to discern the causes and explain them also to others. For the cause of the latter is hardness combined with irregularity, and of the former 64aregularity combined with density.

In respect of the affections common to the whole body a very important point, which still remains, is the cause of the pleasures and pains attaching to the sense-affections we have been discussing; and the cause also of those affections which have become perceptible by means of the bodily parts and involve in themselves concomitant pains and pleasures. Let us, then, try to grasp the causes in connection with every perceptible and imperceptible affection in the following way, 64bbearing in mind the distinction we previously drew ^note between mobile and immobile substances; for it is in this way that we must track down all those facts that we intend to grasp. Whenever what is naturally mobile is impressed by even a small affection, it transmits it in a circle, the particles passing on to one another this identical impression until they reach the organ of intelligence and announce the quality of the agent. But a substance of the opposite kind, being stable and having no circular movement, is only affected in itself and does not move any other adjacent particle; consequently,