"The greatest good is the knowledge of the nature of things."

"The wise man will not be miserable when he is old."

"I have never wished to cater to the crowd; for what I know they do not approve, and what they approve I do not know."

"Let no one when young delay to study philosophy, nor when old grow weary of studying it. For no one is either too early or too late for the health of the soul."

"We are born once and cannot be born twice, but for all eternity must be no more. But you, who are not master of tomorrow, postpone your happiness. Life is wasted by delaying, and each one of us dies w…"