"Observe constantly that all things take place by change, and accustom thyself to consider that the nature of the universe loves nothing so much as to change existing things and to make new things like…"

"If a man is able to show me that I do not think or act right, I will gladly change; for I seek the truth, by which no man was ever injured. But he is injured who abides in his error and ignorance."

"Even for a god, if he wishes to do good, he must do it through the medium of human beings."

"You could leave life right now. Let that determine what you do and say and think."

"Remember that man lives only in the present, in this fleeting instant; all the rest of his life is either past and gone, or still uncertain. Short is the life of man, and short is the span of his plea…"