The Pre-Socratics (the term simply means those philosophers who came before Socrates) came from outlying Greek city-states located on islands far from Athens, which was the cultural center of ancient Greece. Their ideas circulated widely among Greek intellectuals all over the civilized Western world. In chronological order, the main Pre-Socratics were: Thales (c. 624–c. 546 B.C.E.), Anaximander (c. 610–c. 546 B.C.E.), Anaximenes of Miletus (580–500 B.C.E.), Pythagoras (c. 575–495 B.C.E.), Heraclitus (535–475 B.C.E.), Anaxagoras (c. 500–428 B.C.E.), Parmenides (n.d.), Zeno of Elea (c. 490–430 B.C.E.), Empedocles (c. 490–430 B.C.E.), Leucippus (n.d.), and Democratus (c. 460–c. 370 B.C.E.). They were well-educated men who had enough leisure time to ponder deep questions.