Epictetus, "What do you still lack? If, therefore, I show you that what you lack are things most necessary and important for happiness, and that hitherto you have devoted your attention to everything but what was appropriate for you to do, and if I add the colophon, saying: You know neither what God is, nor what man is, nor what good, nor what evil is – if I say that you are ignorant of these other matters you may possibly endure that; but if I say that you do not understand