what does cogito ergo sum mean and is it from a book?
“Cogito, ergo sum” is a philosophical statement used by René Descartes, which became a foundational element of Western philosophy. The simple meaning of the phrase is that if someone is wondering whether or not he exists, that is in and of itself proof that he does exist. Descartes’s original statement was “Je pense donc je suis,” from his Discourse on Method (1637). He uses the Latin “Cogito ergo sum” in the later Principles of Philosophy (1644), Part 1, article 7: “Ac proinde hæc cognitio, ego cogito, ergo sum, est omnium prima & certissima, quæ cuilibet ordine philosophanti occurrat.”, by which time it had become popularly known as ‘the “Cogito Ergo Sum” argument’. Another close quotation, also by Descartes, says “Dubito, ergo cogito, ergo sum” (Latin: “I doubt, therefore I think, therefore I am”).
