Descartes found that he could doubt the existence of everything, except:

Question

Quizplus · Accepted Answer

Descartes' famous statement "Cogito, ergo sum" (I think, therefore I am) reflects his belief that even if everything in the world were an illusion, he could be certain of his own existence as a thinking being. He did not rely on God or the validity of his sensations as a starting point for his philosophy. Option D ("E pluribus Unum") is the motto of the United States, and is unrelated to Descartes' philosophy.

Descartes Found That He Could Doubt the Existence of Everything