Full Idea
It is foolish to study logic unless one is persuaded that one's own reasonings are more or less bad.
Gist of Idea
Only study logic if you think your own reasoning is deficient
Source
Charles Sanders Peirce (Criterion of Validity in Reasoning [1903], II)
Book Reference
Peirce,Charles Sanders: 'Philosophical Writings of Peirce', ed/tr. Buchler,Justus [Dover 1940], p.127