Source: https://emersoncentral.com/texts/letters-social-aims/quotation-and-originality/
Summary:
Read in Plato and you shall find Christian dogmas, and not only so, but stumble on our evangelical phrases. Hegel pre-exists in Proclus, and, long before, in Heraclitus and Parmenides. Whoso knows Plutarch, Lucian, Rabelais, Montaigne and Bayle will have a key to many supposed originalities. Rabelais is the source of many a proverb, story, and jest, derived from him into all modern languages; and if we knew Rabelais's reading we should see the rill of the Rabelais river. Swedenborg, Behmen, Spinoza, will appear original to uninstructed and to thoughtless persons: their originality will disappear to such as are either wellread or thoughtful; for scholars will recognize their dogmas as reappearing in men of a similar intellectual elevation throughout history.
We prize books, and they prize them most who are themselves wise. Our debt to tradition through reading and conversation is so massive, our protest or private addition so rare and insignificant, -- and this commonly on the ground of other reading or hearing, --that, in a large sense, one would say there is no pure originality.
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