Until relatively recently it was not possible to approach the question of ethics without recourse to the Greeks, and in particular Plato, Aristotle, the Cynics, and the Epicureans. Happiness occupies a central place in each of these philosophical works, even though this happiness is not understood in the same sense within each. For Plato it is "purification," the contemplative life, and the city of justice; for Aristotle it is reason and the intellectual life; for the Sophists, Thrasymachus and Callicles it is might, power, utility, and success; for Epicurus it is pleasure; and for the Cynics Chrysippus, Zeno, and Epictetus, it is life in harmony with reason, fate and logos. Despite variation between these meanings, all of these approaches regard happiness as the higher good, virtue, and truth.