Single Idea 12564

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

Full Idea

If I know I doubt, I have as certain a perception of the existence of the thing doubting, as of that thought which I call doubt.

Gist of Idea

I am as certain of the thing doubting, as I am of the doubt

Source

John Locke (Essay Conc Human Understanding (2nd Ed) [1694], 4.09.03)

Book Reference

Locke,John: 'Essay Concerning Human Understanding', ed/tr. Nidditch,P.H. [OUP 1979], p.618


A Reaction

The challenge to this Lockean assertion of the Cogito is what he means by a 'thing', and what grounds he has for asserting the existence of the 'thing', as opposed to some vague assertion about whatever makes doubting possible.