At the same time one might assert, not without reason, that a dryness engendered with the heat subtilizes the spirit of prophecy and renders it ethereal and pure; for this is the dry soul, as Heracleitus has it.A dry soul is best (and/or wisest) is the dictum of Heracleitus, which is often quoted; see Diels, , i. p. 100, Heracleitus, no. b 118; Cf. also , 995 e, and , chap. xxviii. (36 a). Moisture not only dulls sight and hearing, but when it touches mirrors and combines with air, it takes away their brightness and sheen.Cf. Plutarch, , 736 a-b. But again the very opposite of this may not be impossible: that by a sort of chilling and compacting of the spirit of inspiration the prophetic element in the soul, as when steel is dipped in cold water, is rendered tense and keen. And further, just as tin when alloyed with copper, which is loose and porous in texture, binds it together and compacts it,Cf. Aristotle, , ii. 8 (747 a 34). and at the same time makes it brighter and cleaner, even so there is nothing to prevent the prophetic vapour, which contains some affinity and relationship to souls, from filling up the vacant spaces and cementing all together by fitting itself in. For one thing has affinity and adaptability for one thing, another for another, just as the beanCf. H. Blümner, (Leipzig, 1875), i. 236. seems to further the dyeing of purple and sodium carbonateIbid. 238. that of scarlet, when mixed with the dye; All in the linen is blended the splendour of glorious scarlet, as EmpedoclesCf. Diels, , i. p. 255, Empedocles, no. b 93. has said. But regarding the Cydnus and the sacred sword of Apollo in Tarsus we used to hear you say, my dear Demetrius, that the Cydnus will cleanse no steel but that, and no other water will cleanse that sword. There is a similar phenomenon at Olympia, where they pile the ashes against the altar and make them adhere all around by pouring on them water from the Alpheius; but, although they have tried the waters of other rivers, there is none with which they can make the ashes cohere and stay fixed in their place.

It is not, therefore, anything to excite amazement if, although the earth sends up many streams, it is only such as these that dispose souls to inspiration and impressions of the future. Certainly the voice of legend also is in accord with my statement; for they record that here the power hovering about this spot was first made manifest when a certain shepherd fell in by accident and later gave forth inspired utterances, which those who came into contact with him at first treated with disdain; but later, when what he had foretold came to pass, they were amazed. The most learned of the people of Delphi still preserve the tradition of his name, which they say was Coretas. But I incline most to the opinion that the soul acquires towards the prophetic spirit a close and intimate connexion of the sort that vision has towards light, which possesses similar properties. For, although the eye has the power of vision, there is no function for it to perform without lightSee 436 d, infra, and Plato, , 508 a - 509 b.; and so the prophetic power of the soul, like an eye, has need of something kindred to help to kindle it and stimulate it further. Hence many among earlier generations regarded Apollo and the Sun as one and the same god; but those who understood and respected fair and wise analogy conjectured that as body is to soul, vision to intellect, and light to truth, so is the power of the sun to the nature of Apollo; and they would make it appear that the sun is his offspring and progeny, being for ever born of him that is for ever. For the sun kindles and promotes and helps to keep in activity the power of vision in our perceptive senses, just as the god does for the power of prophecy in the soul.

Those, however, who had reached the conclusion that the two are one and the same god very naturally dedicated the oracle to Apollo and Earth in common, thinking that the sun creates the disposition and temperament in the earth from which the prophet-inspiring vapours are wafted forth. As Hesiod,, 117. then, with a better understanding than some philosophers, spoke of the Earth itself as Of All the unshaken foundation, so we believe it to be everlasting and imperishable. But in the case of the powers associated with the earth it is reasonable that there should come to pass disappearances in one place and generation in another place, and elsewrhere shifting of location and, from some other source, changes in current,Cf. 432 e, supra. and that such cycles should complete many revolutions within it in the whole course of time, as we may judge from what happens before our eyes. For in the case of lakes and rivers, and even more frequently in hot springs, there have occurred disappearances and complete extinction in some places, and in others a stealing away, as it were, and sinking under groundA not uncommon phenomenon in Greece; cf., 557 e.; later they came back, appearing after a time in the same places or flowing out from below somewhere near. We know also of the exhaustion of mines, some of which have given out recently, as for example the silver mines of Attica and the copper ore in Euboea from which the cold-forged sword-blades used to be wrought, as AeschylusCf. Nauck, p. 107, Aeschylus, no. 356. The hardness and temper of cold-forged copper is well attested. has said, Euboean sword, self-sharpened, in his hand. And it is no long time since the rock in Euboea ceased to yield, among its other products, soft petrous filaments like yarn.An interesting early notice of the use of asbestos. I think some of you have seen towels, nets, and women’s head-coverings from there, which cannot be burned by fire; but if any become soiled by use, their owners throw them into a blazing fire and take them out bright and clear. To-day all this has disappeared, and there are scarcely any attenuated fibres or hairs, as it were, running through the mines.