"Except our own thoughts, there is nothing absolutely in our power." —Descartes

"As long as you live, keep learning how to live." —Seneca

"A fool is known by his speech; and a wise man by silence." —Pythagoras

"The essence of philosophy is that a man should so live that his happiness shall depend as little as possible on external things." —Epictetus

"The measure of a man is what he does with power." —Plato

"Devote the rest of your life to making progress." —Epictetus