<P> He was an early proponent of science and tried to observe and explain different aspects of the universe, with a particular interest in its origins, claiming that nature is ruled by laws, just like human societies, and anything that disturbs the balance of nature does not last long . Like many thinkers of his time, Anaximander's philosophy included contributions to many disciplines . In astronomy, he attempted to describe the mechanics of celestial bodies in relation to the Earth . In physics, his postulation that the indefinite (or apeiron) was the source of all things led Greek philosophy to a new level of conceptual abstraction . His knowledge of geometry allowed him to introduce the gnomon in Greece . He created a map of the world that contributed greatly to the advancement of geography . He was also involved in the politics of Miletus and was sent as a leader to one of its colonies . </P> <P> Anaximander, son of Praxiades, was born in the third year of the 42nd Olympiad (610 BC). According to Apollodorus of Athens, Greek grammarian of the 2nd century BC, he was sixty - four years old during the second year of the 58th Olympiad (547--546 BC), and died shortly afterwards . </P> <P> Establishing a timeline of his work is now impossible, since no document provides chronological references . Themistius, a 4th - century Byzantine rhetorician, mentions that he was the "first of the known Greeks to publish a written document on nature ." Therefore, his texts would be amongst the earliest written in prose, at least in the Western world . By the time of Plato, his philosophy was almost forgotten, and Aristotle, his successor Theophrastus and a few doxographers provide us with the little information that remains . However, we know from Aristotle that Thales, also from Miletus, precedes Anaximander . It is debatable whether Thales actually was the teacher of Anaximander, but there is no doubt that Anaximander was influenced by Thales' theory that everything is derived from water . One thing that is not debatable is that even the ancient Greeks considered Anaximander to be from the Monist school which began in Miletus, with Thales followed by Anaximander and finished with Anaximenes . 3rd - century Roman rhetorician Aelian depicts him as leader of the Milesian colony to Apollonia on the Black Sea coast, and hence some have inferred that he was a prominent citizen . Indeed, Various History (III, 17) explains that philosophers sometimes also dealt with political matters . It is very likely that leaders of Miletus sent him there as a legislator to create a constitution or simply to maintain the colony's allegiance . </P> <P> Anaximander lived the final few years of his life as a subject of the Persian Achaemenid Empire . </P>

Who asserted that the most fundamental element is water