René Descartes quotes
1596 – 1650 · Early modern Europe, 17th century · Philosopher, mathematician and natural philosopher
About René Descartes
Born in La Haye en Touraine, Descartes sought a first indubitable truth from which knowledge could be rebuilt. A founder of modern rationalism, he argued that the act of thinking or doubting secures the existence of the thinking subject and made key contributions to mathematics and natural philosophy.
Works: Discourse on the Method; Meditations on First Philosophy; Principles of Philosophy
Quotes
“I think, therefore I am.”
Source: Discourse on the Method; Meditations on First Philosophy (1637, 1641) · Check the source
Verified attribution What we know
- What is documented
- Descartes develops the cogito in the Discours de la méthode (1637) and elaborates it in the Meditations (1641).
- What remains uncertain
- The Latin formula cogito ergo sum is a later, canonical condensation; Descartes uses variant wordings and sometimes writes je suis/ego sum instead.
The core insight is that thinking proves a minimal existence: if you are doubting or reflecting, you cannot coherently deny that you are thinking. Descartes treats that self-awareness as the first certain foundation from which knowledge can be rebuilt; the idea is popularly summed as “I think, therefore I am.”