Page "René Descartes" Paragraph 24

Initially, Descartes arrives at only a single principle: thought exists.

Thought cannot be separated from me, therefore, I exist ( Discourse on the Method and Principles of Philosophy ).

Most famously, this is known as cogito ergo sum ( English: " I think, therefore I am ").

Therefore, Descartes concluded, if he doubted, then something or someone must be doing the doubting, therefore the very fact that he doubted proved his existence.

" The simple meaning of the phrase is that if one is sceptical of existence, that is in and of itself proof that he does exist.