Page:Early Greek philosophy by John Burnet, 3rd edition, 1920.djvu/76

62 doubt that we are entitled to regard this as the doctrine of Anaximander and Anaximenes. It would arise very naturally in the minds of thinkers who started with water as the primary substance and ended with "air," and it would account admirably for the position of earth and water in the centre and fire at the circumference, with "air" between them. Heavy things tend to the centre of a vortex and light things are forced out to the periphery. It is to be observed that there is no question of a sphere in revolution at this date; what we have to picture is rotary motion in a plane or planes more or less inclined to the earth's surface. It is in favour of the conjecture given above as to the nature of the primordial motion that it provides a satisfactory dynamical explanation of the formation of the δίνη, and we shall find once more (§180) that the Atomists held precisely this view of its origin.

19. The doxographers also give us some indications of the process by which the different parts of the world arose from the Boundless. The following statement comes ultimately from Theophrastos: