"What is morally wrong can never be advantageous, even when it enables you to make some gain that you believe to be to your advantage. The mere act of believing that some wrongful course of action constitutes an advantage is pernicious."
"To study philosophy is nothing but to prepare one’s self to die."
"When you wish to instruct, be brief; that men's [children's] minds take in quickly what you say, learn its lesson, and retain it faithfully. Every word that is unnecessary only pours over the side of a brimming mind."
"The face is a picture of the mind with the eyes as its interpreter."
"The life given us, by nature is short; but the memory of a well-spent life is eternal."
"O philosophy, life's guide! O searcher-out of virtue and expeller of vices! What could we and every age of men have been without thee? Thou hast produced cities; thou hast called men scattered about into the social enjoyment of life."