- Charles H. Kahn
Anaximander of *Miletu (died soon after 547 BCE), said to be an associate or disciple of *Thales, was the first Greek to write a prose treatise ‘On the Nature of Things’ (Peri physeōs). He thus initiated the tradition of Greek natural philosophy by elaborating a system of the heavens, including an account of the origins of human life, and by leaving his speculation behind in written form. He was the first to make a *map of the inhabited world; some sources also credit him with a sphairos or plan of the heavens.
Anaximander's view of the cosmos is remarkable for its speculative imagination and for its systematic appeal to rational principles and natural processes as a basis for explanation. The origin of things is the apeiron, the limitless or infinite, which apparently surrounds the generated world and ‘steers’ or governs the world process. Symmetry probably dictates that the world-order will perish into the source from which it has arisen, as symmetry is explicitly said to explain why the earth is stable in the centre of things, equally balanced in every direction. The world process begins when the opposites are ‘separated out’ to generate the hot and the cold, the dry and the wet. By a process that is both biological and mechanical, earth, sea, and sky take shape and huge wheels of enclosed fire are formed to produce the phenomena of sun, moon, and stars. The size of the wheels was specified, corresponding perhaps to the arithmetical series 9, 18, 27. The earth is a flat disc, three times as broad as it is deep. Mechanical explanations in terms of the opposites are offered for meteorological phenomena (wind, rain, lightning, and thunder) and for the origin of animal life. The first human beings were generated from a sort of embryo floating in the sea.