I think, therefore I am.
Source: A Discourse on Method (1637), Part IV
Author
French · 1596-1650 · 10 quotes
French · 1596–1650
10 quotes in our collection
René Descartes (1596-1650) was a French philosopher, mathematician, and scientist whose work helped define modern philosophy. His major writings include Discourse on the Method, Meditations on First Philosophy, Principles of Philosophy, Rules for the Direction of the Mind, and Geometry. Descartes matters because he made radical doubt a path toward certainty, arguing from the famous cogito: I think, therefore I am. He also contributed to analytic geometry and mechanistic natural philosophy, linking mathematics, method, and inquiry in ways that shaped modern science. His mind-body dualism, arguments for God, and theory of knowledge became central points of debate for later philosophers. Descartes' quotes endure because they ask how thought can be disciplined, how certainty can be sought, and how a strong mind must be rightly applied rather than merely possessed. His method still stands behind modern arguments about reason and certainty.
Common Themes
Collected Quotes
I think, therefore I am.
Good sense is, of all things among men, the most equally distributed.
For to be possessed of a vigorous mind is not enough; the prime requisite is rightly to apply it.
The reading, not of all books, but especially of such as have been written by persons capable of conveying proper instruction, for it is a species of conversation we hold with their authors.
It does not suffice that the understanding be good - it must be well applied.
The greatest minds, as they are capable of the highest excellences, are open likewise to the greatest aberrations.
The first degree contains only notions so clear of themselves that they can be acquired without meditation.
My mind is no better than another's, but I have been lucky enough to chance on certain ways, which have led me to a certain method by means of which it seems to me that I may by degrees augment my knowledge to the modest measure of my intellect and my length of days.