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Philosophical Works · Chapter

Discourse on the Method explained

Descartes recounts his method of radical doubt, rejecting all beliefs that could be doubted, leading to the first certainty: 'I think, therefore I am.' He establishes the mind as distinct from the body, uses the idea of a perfect being to p

What happens

Descartes recounts his method of radical doubt, rejecting all beliefs that could be doubted, leading to the first certainty: 'I think, therefore I am.' He establishes the mind as distinct from the body, uses the idea of a perfect being to prove God's existence, and outlines his plan to explain the material world through laws established by God.

Themes in this chapter

  • Methodical Doubt

    Descartes resolves to reject as absolutely false any opinion that could be doubted, including sensory perceptions and mathematical truths.

  • Cogito Ergo Sum (I Think, Therefore I Am)

    The first principle of Descartes' philosophy: the certainty of his own existence as a thinking thing, immune to the most extravagant skeptical doubts.

  • Existence of God

    Descartes argues that the idea of a perfect being must originate from a perfect reality, leading to a proof of God's existence and His role as guarantor of truth.

Characters to notice

  • Narrator

    The first-person narrator who undertakes the method of doubt and discovers the cogito.

  • René Descartes

    The philosopher who systematically doubts all previous beliefs to find indubitable truth.

  • God

    Invoked as the guarantor of clear and distinct perceptions and as the creator of the laws of nature.

Key passages

  • I ought to reject as absolutely false all opinions in regard to which I could suppose the least ground for doubt

    Descartes decides to treat any belief that can be doubted as completely false.

    This is the foundational step of his methodical doubt.

  • I think, hence I am

    The act of thinking proves the existence of the thinker.

    This is the cogito, the first indubitable truth Descartes discovers.

  • I was a substance whose whole essence or nature consists only in thinking

    Descartes concludes that his true nature is to be a thinking thing, independent of the body.

    This establishes mind-body dualism.

  • I clearly recognized that I must hold this notion from some nature which in reality was more perfect

    The idea of a perfect being must come from a perfect source, which is God.

    This is Descartes' argument for God's existence from the idea of perfection.