Timelines of Greek Philosophers (dates according to Kirk, Raven, Schofield, The Presocratic Philosophers and Oxford Classical Dictionary 3rd edition)

700 BCE
            Thales            c. b. 625
            Anaximander b c. 611
600 BCE
            Anaximenes  b. c. 587
            Xenophanes  b. 570 – 478 (at least)
            Heraclitus  b. c. 540
            Pythagoras  active in second half sixth century
            Parmenides  b.515
500 BCE
            Anaxagoras  b. 500
            Zeno of Elea  b. 490
            Empedocles  c. 495-35
            Pericles  495-429
            Democritus  b. 460
            Socrates  469-399
            Plato 427-347
            Speusippus 407-339
400 BCE
            Aristotle 384-322
            Theophrastus 371-287
            Alexander the Great 356-323