Thales of Miletus (pronounced /ˈθeɪliːz/; Greek: Θαλῆς, Thalēs; c. 624 BC – c. 546 BC) was a pre-Socratic Greek philosopher from Miletus in Asia Minor.According to Bertrand Russell, "Western philosophy begins with Thales."[2] Thales attempted to explain natural phenomena without reference to mythology and was tremendously influential in this respect.Water as a first principle Thales' most famous belief was his cosmological thesis, which held that the world started from water. Aristotle considered this belief roughly equivalent to the later ideas of Anaximenes, who held that everything in the world was composed of air. The best explanation of Thales' view is the following passage from Aristotle's Metaphysics.[15] The passage contains words from the theory of matter and form that were adopted by science with quite different meanings. "That from which is everything that exists (ἅπαντα τὰ ὄντα) and from which it first becomes (ἐξ οὗ γίγνεται πρῶτου) and into which it is rendered at last (εἰς ὃ φθείρεται τελευταῖον), its substance remaining under it (τῆς μὲν οὐσίας ὑπομενούσης), but transforming in qualities (τοῖς δὲ πάθεσι μεταβαλλούσης), that they say is the element (στοιχεῖον) and principle (ἀρχήν) of things that are." And again: "For it is necessary that there be some nature (φύσις), either one or more than one, from which become the other things of the object being saved... Thales the founder of this type of philosophy says that it is water."