more on this theme     |     more from this thinker     |     more from this text

---

Single Idea 3658

[filed under theme 11. Knowledge Aims / B. Certain Knowledge / 4. The Cogito ]

Full Idea

He who decides to doubt everything cannot nevertheless doubt that he exists while he doubts.

Gist of Idea

Total doubt can't include your existence while doubting

Source

René Descartes (Principles of Philosophy [1646], Pref)

Book Ref

Descartes,René: 'Philosophical Essays and Correspondence', ed/tr. Ariew,Roger [Hackett 2000], p.226