The Milesian school was a school of thought founded in the 6th Century BC. The ideas associated with it are exemplified by three philosophers from the Ionian town of Miletus, on the edge of Anatolia: Thales, Anaximander, and Anaximenes. They introduced new opinions contrary to the prevailing viewpoint on how the world was organized, in which natural phenomena were explained by the whims of anthropomorphized beings. The Milesians presented a view of nature in terms of methodologically observable entities, and as such was one of the first truly scientific philosophies.

Note: It is important to make a distinction between the Milesian school and the Ionian, which includes the philosophies of both the Milesians and other distinctly different Ionian thinkers such as Heraclitus. See also Pre-Socratic philosophy.

Philosophy of nature