A man's true greatness lies in the consciousness of an honest purpose in life, founded on a just estimate of himself and everything else, on frequent self-examinations, and a steady obedience to the rule which he knows to be right, without troubling himself about what others may think or say, or whether they do or do not that which he thinks and says and does.

The Thoughts of the Emperor Marcus Aurelius Antoninus. Translated by George Long (ed. 1862)