In the sixth century BC, Anaximander of Miletus, an associate of Thales, initiated Western philosophy and science with an inquiry into `the nature of things` which included a theory of how the world order arose, how the heavens and earth were formed, and how human beings came into existence. Anaximander was the first thinker to propose a geometric model to explain the movement of the heavenly bodies; the cosmological ideas of his school provided the background for all ancient Greek views of the natural world. This new printing of the corrected Centrum printing of 1985 makes available again a work of value for students in classics, philosophy, literature, and the history of science.

Charles H Kahn is Professor of Philosophy, University of Pennsylvania.