Always follow these two rules: first, act only on what your reasoning mind proposes for the good of humanity, and second, change your opinion if someone shows you it's wrong. This change of mind must proceed only from the conviction that it's both correct and for the common good, but not because it will give you pleasure and make you popular.
Marcus AureliusSince you are an integral part of a social system, let every act of yours contribute to the harmonization of social life. Any action that is not related directly or remotely to this social aim disturbs your life, and destroys your unity.
Marcus AureliusIs your cucumber bitter? Throw it away. Are there briars in your path? Turn aside. That is enough. Do not go on and say, "Why were things of this sort ever brought into this world?" neither intolerable nor everlasting - if thou bearest in mind that it has its limits, and if thou addest nothing to it in imagination. Pain is either an evil to the body (then let the body say what it thinks of it!)-or to the soul. But it is in the power of the soul to maintain its own serenity and tranquility. . . .
Marcus AureliusChoose not to be harmed and you won't feel harmed. Don't feel harmed and you haven't been.
Marcus AureliusA 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.
Marcus Aurelius