Thales was born into a noble family of Phoenician origin at the time of the 25th Olympiad (floruit 585 bc; he was 40 in the year of the solar eclipse. He had no teachers but had occasion to learn from Egyptian priests. He developed into a scholar and politician very much appreciated by Heraclitus, Herodotus and Democritus, and was always considered a man of practical wisdom. He was probably the first to speak about the immortality of the soul. He is listed as the first of many unmarried men who paved the road for philosophy. For Diogenes Laertius (Lives and Opinions of Eminent Philosophers), he was the instructor of Anaximander. Thales, the man who first discovered how to draw a right-angle triangle in a circle, was the first philosopher of nature (physis). "Philosophy begins with Thales," pointed out Bertrand Russell in 1961. This honor had been conceded also by Aristotle: "Anaximander, Thales' pupil, founded the Ionian tradition of philosophy." Many explanations may be given for the importance of water, including its importance for living processes, the economic role of the Nile, the importance of the port for Miletus and the fact that Ocean and Thetys were in Homer's tradition progenitors of the world.