If you are distressed by something, it is due to your own estimate of it; and you have the power to change it at will.
Marcus AureliusDig inside. Inside is the fountain of good, and it will forever flow, if you will forever dig.
Marcus AureliusA noble man compares and estimates himself by an idea which is higher than himself; and a mean man, by one lower than himself. The one produces aspiration; the other ambition, which is the way in which a vulgar man aspires.
Marcus AureliusFor nowhere either with more quiet or more freedom from trouble does a man retire than into his own soul, particularly when he has within him such thoughts that by looking into them he is immediately in perfect tranquility; and I affirm that tranquility is nothing else than the good ordering of the mind.
Marcus Aurelius