Full Idea
A truth which rests on the authority of inspiration only is of a somewhat incomprehensible nature; and we can never be sure that we rightly comprehend it.
Gist of Idea
A truth is hard for us to understand if it rests on nothing but inspiration
Source
Charles Sanders Peirce (Scientific Attitude and Fallibilism [1899], II)
Book Reference
Peirce,Charles Sanders: 'Philosophical Writings of Peirce', ed/tr. Buchler,Justus [Dover 1940], p.57