Plutarch, De defectu oraculorum
Frank Cole Babbitt, Ed.

“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; [p. 475] 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 light¹; 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.