Cogito, ergo sum

Phrase of the philosopher René Descartes

The Latin cogito, ergo sum, usually translated into English as "I think, therefore I am", is the "first principle" of the philosophy of the French scientist and philosopher René Descartes. He originally published it in French as je pense, donc je suis in his 1637 Discourse on the Method, so as to reach a wider audience than Latin would have allowed. It later appeared in Latin in his Principles of Philosophy, and a similar phrase (ego sum, ego existo, 'I am, I exist') also featured prominently in his Meditations on First Philosophy.

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