Descartes Publishes the Discourse on Method
"I think, therefore I am" becomes the one thing a thinker cannot doubt
Quick facts
- Author
- Rene Descartes
- Work
- Discourse on Method
- Published
- 1637
- Key phrase
- Cogito, ergo sum (I think, therefore I am)
What happened
In 1637 Rene Descartes published the Discourse on Method, written in French rather than scholarly Latin so an educated general reader could follow it. Descartes proposed stripping away every belief that could possibly be doubted, including the evidence of the senses, to find something certain to rebuild knowledge on. He found it in the act of doubting itself: even if he doubted everything else, the fact that he was thinking proved he existed, summarized later as "cogito, ergo sum", I think, therefore I am. From that single certainty he tried to reconstruct a foundation for science built on clear and distinct ideas rather than inherited scholastic authority.
Why it matters
The cogito made the individual thinking mind, not scripture or Aristotle, the starting point for certainty, a move historians treat as one of the hinges between medieval and modern philosophy. It set the terms for a running argument about the reliability of reason versus the senses that Locke, Hume, and Kant would each answer differently over the following century and a half.
How we know
The Discourse survives in Descartes' original French and in later editions collecting his complete works; the Stanford Encyclopedia of Philosophy's entry on Descartes traces the cogito argument to these texts and to his later Meditations.
Sources
- Stanford Encyclopedia of Philosophy. Rene Descartes · Reputable sourceplato.stanford.edu · The domain "plato.stanford.edu" is on our Reputable source registry. · Link is live and its text matches the event's key terms (Jul 2026)
- Rene Descartes, trans. John Veitch (Project Gutenberg). A Discourse on Method · Primary source (author-declared)gutenberg.org · Cited as a "primary" source (no stronger domain match). · Link is live and its text matches the event's key terms (Jul 2026)
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