1001Philosophers

David Hume vs Rene Descartes on Knowledge

Descartes and Hume frame the central dispute of early modern epistemology. Descartes holds that certain knowledge requires a foundation in clear and distinct ideas accessible to reason alone, and the cogito provides that foundation. Hume rejects the project: there is no impression of the self, no necessary connection given in experience, and no rational foundation of the kind Descartes sought; what we call knowledge is grounded in custom and habit rather than in reason.

About this topic

Epistemology is the branch of philosophy concerned with the nature, sources, and limits of knowledge. Philosophers have asked what distinguishes knowledge from mere opinion, whether it requires certainty or can be probabilistic, and how perception, reason, memory, and testimony each contribute. Ancient skeptics challenged the possibility of knowledge altogether, while rationalists located its source in reason and empiricists in experience. Contemporary epistemology investigates justification, reliability, and the social conditions under which beliefs count as knowing.

For a side-by-side overview of the two philosophers more broadly, see the full David Hume vs Rene Descartes comparison. To browse philosophy more widely on this theme, see the Knowledge quotes hub.

Representative quotes on knowledge

David Hume on knowledge

  • “A wise man proportions his belief to the evidence.”

    Section X: Of Miracles; Part I. 87

  • “Generally speaking, the errors in religion are dangerous; those in philosophy only ridiculous.”

    Part 4, Section 7

  • “All knowledge degenerates into probability.”

    Part 4, Section 1

  • “When men are most sure and arrogant they are commonly most mistaken.”

    § 9.13 : Conclusion, Pt. 1

  • “Of Money (1752) as quoted in David Hume: Writings on Economics (1955, 1970) ed., Eugene Rotwein, p. 45.”

    Here then we may learn the fallacy of the remark... that any particular state is weak, though fertile, populous, and well cultivated, merely because it wants money . It appears that the want of money can never injure any state within itself: For men and commodities are the real strength of any community. It is the simple manner of living which here hurts the public, by confining the gold and silve

All 10 David Hume quotes on knowledge →

Rene Descartes on knowledge

  • “I think, therefore I am.”

    Je pense, donc je suis.

  • “If you would be a real seeker after truth, it is necessary that at least once in your life you doubt, as far as possible, all things.”

    In order to seek truth, it is necessary once in the course of our life, to doubt, as far as possible, of all things.

  • “No doubt you know that Galileo had been convicted not long ago by the Inquisition, and that his opinion on the movement of the Earth had been condemned as heresy. Now I will tell you that all things I explain in my treatise , among which is also that same opinion about the movement of the Earth, all depend on one another, and are based upon certain evident truths. Nevertheless, I will not for the world stand up against the authority of the Church. ...I have the desire to live in peace and to continue on the road on which I have started.”

    Letter to Marin Mersenne (end of Feb., 1634) as quoted by Amir Aczel , Pendulum: Leon Foucault and the Triumph of Science (2003)

  • “Letter to Marin Mersenne (end of Feb., 1634) as quoted by Amir Aczel , Pendulum: Leon Foucault and the Triumph of Science (2003)”

    No doubt you know that Galileo had been convicted not long ago by the Inquisition, and that his opinion on the movement of the Earth had been condemned as heresy. Now I will tell you that all things I explain in my treatise , among which is also that same opinion about the movement of the Earth, all depend on one another, and are based upon certain evident truths. Nevertheless, I will not for the

  • “Letter to Marin Mersenne (1637) as quoted by D. E. Smith & M. L. Latham Tr. The Geometry of René Descartes (1925)”

    What I have given in the second book on the nature and properties of curved lines, and the method of examining them, is, it seems to me, as far beyond the treatment in the ordinary geometry, as the rhetoric of Cicero is beyond the a, b, c of children.

All 13 Rene Descartes quotes on knowledge →

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