Discourse on the Method

Of Rightly Conducting the Reason, and Seeking Truth in the Sciences

René Descartes 1637

A short, personal account tells how one thinker doubted everything and rebuilt his knowledge from the ground up. The one thing he cannot doubt gives the book its famous line: I think, therefore I am.

75 pages 1h 28m reading time

  • A founding text of modern philosophy.
  • Resolves to doubt everything that can be doubted, then rebuild knowledge only on what is certain.
  • Finds one certainty that survives doubt, "I think, therefore I am," one of the most famous lines in philosophy.
  • Its method of breaking problems into parts and reasoning step by step helped shape the Scientific Revolution.
  • Its geometry appendix helped found analytic geometry (algebra applied to shapes), the basis of the graphs we still call Cartesian.

  • Shaped by Galileo's trial

    After the Church condemned Galileo in 1633, Descartes held back his book on physics and published this instead.

  • Published without his name

    It first appeared in Leiden, in the Dutch Republic, with no author's name on the title page.

  • Written in French, not Latin

    He chose French over Latin, the language of scholars, so ordinary readers could follow his reasoning.

  • Born in a heated room

    He says his key ideas came to him on a winter day alone in a stove-heated room in Germany.

Translated from French by John Veitch 1850