Page:Early Greek philosophy by John Burnet, 3rd edition, 1920.djvu/75

Rh arranged in a triangle, which shows at least that the doctrine of a plurality of worlds was much older than the Atomists.

18. The doxographers say it was the "eternal motion" that brought into being "all the heavens and all the worlds within them." We have seen (§ VIII.) that this is probably only the Aristotelian way of putting the thing, and that we must not identify the primordial motion of the Boundless with any purely mundane movement such as the diurnal revolution. That would be quite inconsistent, moreover, with the doctrine of innumerable worlds, each of which has, presumably, its own centre and its own diurnal revolution. As to the true nature of this motion, we have no definite statement, but the term "separating off" (ἀπόκρισις) rather suggests some process of shaking and sifting as in a riddle or sieve. That is given in Plato's Timaeus as the Pythagorean doctrine, and the Pythagoreans followed Anaximander pretty closely in their cosmology (§ 54). The school of Abdera, as will be shown (§ 179), attributed a motion of the same kind to their atoms, and they too were mainly dependent on the Milesians for the details of their system. This, however, must remain a conjecture in the absence of express testimony.

When, however, we come to the motion of the world once it has been "separated off," we are on safer ground. It is certain that one of the chief features of early cosmology is the part. played in it by the analogy of an eddy in water or in wind, a δίνη (or δῖνος), and there seems to be little