Meditations, Book 1, Section 5

Marcus Aurelius — The Emperor

From Apollonius I learned true freedom and steady consistency. He taught me not to care about anything, no matter how small, except what is right and reasonable. He stayed the same person whether in sharp pain, after losing a child, or during long illness. He showed me that one man can be both intense and relaxed. He never got annoyed with slow students during his lectures. He was a perfect example of someone who valued least in himself his greatest gift — his excellent ability to teach Stoic philosophy to others. From him I also learned how to accept favors from friends. I learned not to become dependent on their kindness, and not to give in too much when I shouldn't. But I also learned not to seem cold and ungrateful.

Marcus Aurelius — The Emperor Original

From Apollonius, true liberty, and unvariable steadfastness, and not to regard anything at all, though never so little, but right and reason: and always, whether in the sharpest pains, or after the loss of a child, or in long diseases, to be still the same man; who also was a present and visible example unto me, that it was possible for the same man to be both vehement and remiss: a man not subject to be vexed, and offended with the incapacity of his scholars and auditors in his lectures and expositions; and a true pattern of a man who of all his good gifts and faculties, least esteemed in himself, that his excellent skill and ability to teach and persuade others the common theorems and maxims of the Stoic philosophy. Of him also I learned how to receive favours and kindnesses (as commonly they are accounted:) from friends, so that I might not become obnoxious unto them, for them, nor more yielding upon occasion, than in right I ought; and yet so that I should not pass them neither, as an unsensible and unthankful man.