A passage from Epictetus
Epictetus, Enchiridion 6
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Don't be prideful with any excellence that is not your own. If a horse should be prideful and say, 'I am handsome,' it would be supportable. But when you are prideful, and say, 'I have a handsome horse,' know that you are proud of what is, in fact, only the good of the horse.
Related passages
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At dawn, when you have trouble getting out of bed, tell yourself: 'I have to go to work — as a human being.'
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Take care not to be Caesarified, or dyed with purple; for it does happen. Keep thyself then simple, good, pure, serious, free from affectation.
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It is a man's special privilege to love even those who wrong him.