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Discourse on the Method

by René Descartes

Descartes sets aside every uncertain belief and rebuilds knowledge from a single certainty discovered by his own reason.

PhilosophyMindScienceIndividualismCharacter

Idea map

The book in 6 ideas

Rebuild Knowledge on Reason Descartes doubts all uncertain belief and rebuilds knowledge by method from a single certainty, then extends it toward nature.
  • Old Learning

    Schooling left him doubting the received sciences and trusting reason over inherited opinion.
    • Good Sense Shared Reason is equal in all.
    • Doubt the Sciences The sciences are uncertain.
  • Method

    A few firm precepts govern how reason should proceed in any inquiry.
    • Clear and Distinct Accept only the clear.
    • Divide Difficulties Break problems into parts.
    • Order and Review Move in order; review all.
  • Provisional Morals

    A provisional code of morals lets him live well while judgment is suspended.
    • Laws and Customs Keep to local custom.
    • Resolute Action Act firmly once decided.
    • Master Yourself Govern your own desires.
  • First Certainties

    Doubting everything, he finds the thinking self, the mind, and God to be certain.
    • Total Doubt Reject what can be doubted.
      • Senses Deceive: The senses can mislead.
      • Dream Doubt: Waking may resemble dreaming.
    • Thinking Self The thinker must exist.
    • Mind and Body Mind is distinct from body.
    • Existence of God Reason toward perfection.
  • Order of Nature

    His principles extend to the laws of nature, living bodies, and the human soul.
    • Laws of Nature Fixed laws in nature.
    • Motion of the Heart The body as mechanism.
    • Man and Brutes Reason and speech set man apart.
  • Advancing Science

    He weighs why to publish and how shared experiment can carry knowledge forward.
    • Practical Philosophy Useful knowledge of nature.
    • Shared Experiment Many hands, many experiments.

Mental models

3 ways of thinking you can use

Rebuild the House

Tear down beliefs taken on trust and reconstruct them on a foundation you have examined yourself.

How it helps

It separates what you genuinely know from what you merely inherited.

Clear and Distinct

Affirm only what the mind perceives so clearly and distinctly as to leave no ground for doubt.

How it helps

It gives a working standard for deciding what to accept as true.

Conquer Yourself, Not Fortune

Change your desires rather than the order of the world, since only your own thoughts lie fully in your power.

How it helps

It directs effort toward what can actually be governed.

Summary

The essence in plain English

The Discourse opens with the claim that good sense is shared equally among all people. What separates minds is not the amount of reason they hold but the paths along which they conduct their thoughts, and the prime requisite is to apply reason rightly.

Dissatisfied with the learning he received, Descartes describes resolving to sweep away the opinions he had accepted on trust. Rather than reform others or the state, he undertakes only to rebuild the foundation of his own beliefs.

He compresses his procedure into four precepts: to accept nothing as true that is not clearly and distinctly known, to divide each difficulty into parts, to proceed in order from the simplest objects to the more complex, and to make enumerations so complete that nothing is omitted.

Because suspending all judgment would leave him unable to act, he adopts a provisional code of morals: to obey the laws and customs of his country, to be firm and resolute once a course is chosen, and to master himself rather than fortune, changing his desires rather than the order of the world.

Turning to metaphysics, he rejects everything doubtful and finds that the one thing he cannot doubt is that he who thinks must exist. From this he concludes that the mind, whose essence is thinking, is distinct from the body, and proceeds to argue from his idea of perfection to the existence of God.

Key concepts

Terms to know

Methodical Doubt
Descartes deliberately rejects every belief open to the least doubt to test what remains certain.
Why it matters: It clears away inherited opinion so knowledge can rest on a secure foundation.
The Four Precepts
Inquiry is governed by clarity, division of difficulties, ordered progress, and complete review.
Why it matters: It gives reason a disciplined procedure rather than leaving it to habit and chance.
The Thinking Self
Even while doubting everything, the one who thinks must exist.
Why it matters: It supplies the first certain principle on which the rest is built.

Selected Quotes

Short passages from the source

Good sense is, of all things among men, the most equally distributed
René Descartes, Discourse on the Method
I see very clearly that in order to think it is necessary to exist
René Descartes, Discourse on the Method
to endeavor always to conquer myself rather than fortune, and change my desires rather than the order of the world
René Descartes, Discourse on the Method

Source

Text used for this page

Source text: Project Gutenberg edition of Discourse on the Method by René Descartes.

HTML text: https://www.gutenberg.org/cache/epub/59/pg59-images.html

Project Gutenberg states that this ebook is for use at no cost with almost no restrictions in the United States and most other parts of the world, subject to local law.

First published 1637; the Project Gutenberg edition uses John Veitch's translation.