A passage from Marcus Aurelius
Marcus Aurelius, Meditations 6.13
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How good it is, when thou hast roasted meats and such eatables before thee, to impress on thy mind that this is the dead body of a fish, and this is the dead body of a bird or of a pig... Such then are these impressions, and they reach the things themselves and penetrate them, and so we see the things as they truly are.
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