Page:Early Greek philosophy by John Burnet, 3rd edition, 1920.djvu/169

Rh and death as thirty years, the shortest time in which a man may become a grandfather (frs. 87–89).

76. Let us turn now to the world. Diogenes tells us that fire was kept up by the bright vapours from land and and sea, and moisture by the dark. What are these "dark" vapours which increase the moist element? If we remember the "Air" of Anaximenes, we shall be inclined to regard them as darkness itself. We know that the idea of darkness as privation of light is not primitive. I suppose, then, that Herakleitos believed night and winter to be produced by the rise of darkness from earth and sea—he saw, of course, that the valleys were dark before the hill-tops—and that this darkness, being moist, so increased the watery element as to put out the sun's light. This, however, destroys the power of darkness itself. It can no longer rise upwards unless the sun gives it motion, and so it becomes possible for a fresh sun (fr. 32) to be kindled, and to nourish itself at the expense of the moist element for a time. But it can only be for a time. The sun, by burning up the bright vapour, deprives himself of nourishment, and the dark vapour once more gets the upper hand. It is in this sense that "day and night are one" (fr. 35). Each implies the other; they are merely two sides of one process, in which alone their true ground of explanation is to be found (fr. 36).

Summer and winter were to be explained in the same way. We know that the "turnings back" of the sun were a subject of interest in those days, and it was natural for Herakleitos to see in its retreat to the south the advance of the moist element, caused by the heat of the sun itself.