ethical hedonism. Xenophon (c. 427 - 355 BCE). Philosopher of history. Plato (c. 427 - 347 BCE). Famed for view of the transcendental forms. Advocated polity governed by philosophers. Diogenes of Sinope (c. 399 - 323 BCE). Cynic . Xenocrates (c. 396 - 314 BCE). Disciple of Plato. Aristotle (c. 384