Full Idea
The very fact that everybody so ridiculously overrates his own reasoning, is sufficient to show how superficial the faculty is.
Gist of Idea
Everybody overrates their own reasoning, so it is clearly superficial
Source
Charles Sanders Peirce (Reasoning and the Logic of Things [1898], I)
Book Reference
Peirce,Charles Sanders: 'Reasoning and the Logic of Things', ed/tr. Ketner,K.L. [Harvard 1992], p.110
A Reaction
A nice remark. The obvious counter-thought is that the collective reasoning of mankind really has been rather impressive, even though people haven't yet figured out how to live at peace with one another.