9
Since fire is not only warm but bright, the opposite natural entity (they say) must be both cold and dark: as gloomy is the opposite of bright, so is cold of hot. Besides, as darkness confounds the sight, so cold confuses the sense of touch. Heat, on the other hand, transmits the sensation of touching, as brightness does that of seeing. It follows, then, that in nature the primordially dark is also the primordially cold; and that it is air which is primordially dark does not, in fact, escape the notice of the poets since they use the term air for darkness: Thick air lay all about the ships, nor could The moon shine forth from heaven.Homer, Odyssey, ix. 144-145. Words for air in Homer often mean mist or fog. And another instance: So clad in air they visit all the earth.Hesiod, Works and Days, 255. And another: The air at once he scattered and dispelled the mist; The sun shone forth and all the battle carne in view.Homer, Iliad, xvii. 649-650. They also call the lightless air knephas, being as it were, kenon phaous void of light; and collected and condensed air has been termed nephos cloud because it is a negation of light.Plutarch’s etymologies here are no more scientific or convincing than those to be found in his Roman Questions, L.C.L. vol. iv, pp. 6-171. Flecks in the sky and mist and fog and anything else that does not provide a transparent medium for light to reach our senses are merely variations of air; and its invisible and colourless part is called Hades and Acheron.Invisible; cf. 953 a below and Plato, Cratylus, 403 a ff.; Phaedo, 81 c-d and contrast Mor. 942 f supra; colourless, achroston, Acheron. Cf. L. Parmentier, Recherches sur le traite d’Isis et d’Osiris de Plut., Mem. Acad. Belg. ii. 2 (1912/13), pp. 71 ff. In the same way, then, as air is dark when light is gone, so when heat departs the residue is cold air and nothing else. And this is the reason why it has been termed Tartarus because of its coldness. HesiodTheogony, 119; contrast Plato, Phaedo, 112 a ff. makes this obvious when he writes murky Tartarus; and to shake and shiver with cold is to tartarize. Cf. Servius on Vergil, Aen. vi. 577. Such, then, is the reason for these names.
