A passage from Marcus Aurelius
Marcus Aurelius, Meditations 4.25
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Hasten to examine thy own governing part and the things about it. If there is anything in it that is diseased, reject it. But if thou seest it free from disease, consider no other thing.
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Men seek retreats for themselves, houses in the country, sea-shores, and mountains... But this is altogether a mark of the most common sort of men, for it is in thy power whenever thou shalt choose to retire into thyself.
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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.