Anaximander of Miletus was a pupil of Thales and teacher of Anaximenes. Together they formed what we call the Milesian School of Pre-Socratic philosophy. He is credited with inventing the gnomon on the sundial and with drawing a map of the world in which people live. Like his teacher, he believed in an arche (principle) that was at the basis of all the universe, but for him, it was an indefinite nature apeiron. All things came out of the apeiron through a process using heat and cold. Anaximander may have been the first to write a philosophical treatise.
One fragment of his writing remains which says: They pay penalty and retribution to each other for their injustice in accordance with the ordering of time.
Also see: Notable Ancient PeopleMain Source: Curd, Patricia, "Presocratic Philosophy", The Stanford Encyclopedia of Philosophy, Edward N. Zalta (ed.).
