Meditations 10.11

Acquire the contemplative way of seeing how all things change into one another, and constantly attend to it, and exercise thyself about this part [of philosophy]. For nothing is so much adapted to produce magnanimity. Such a man has put off the body, and as he sees that he must, no one knows how soon, go away from among men and leave everything here, he gives himself up entirely to just doing in all his actions, and in everything else that happens he resigns himself to the universal nature. But as to what any man shall say or think about him or do against him, he never even thinks of it, being himself contented with these two things—with acting justly in what he now does, and being satisfied with what is now assigned to him; and he lays aside all distracting and busy pursuits, and desires nothing else than to accomplish the straight course through the law and by accomplishing the straight course to follow God.

Marcus Aurelius, Meditations 10.11, translated by George Long

Make thy own a scientific system of enquiry into the mutual change of all things, and pay diligent heed to this branch of study and exercise thyself in it. For nothing is so conducive to greatness of mind. Let a man do this and he divests himself of his body and, realizing that he must almost at once relinquish all these things and depart from among men, he gives himself up wholly to just dealing in all his actions, and to the Universal Nature in all that befalls him. What others may say or think about him or do against him he does not even let enter his mind, being well satisfied with these two things—justice in all present acts and contentment with his present lot. And he gives up all engrossing cares and ambitions, and has no other wish than to achieve the straight course through the Law and, by achieving it, to be a follower of God.

Marcus Aurelius, Meditations 10.11, translated by C. R. Haines