Anaximenes of Miletus ( c. 585 BC-c . 525 BC ) was a Greek Pre-Socratic philosopher from the latter half of the 6th century , probably a younger contemporary of Anaximander , whose pupil or friend he is said to have been . Anaximenes of Miletus ( b. 585 BCE , d. 528 BCE ) was an Archaic Greek Pre-Socratic philosopher also known as the father of philosophy active in the latter half of the 6th century BC .