Charles Sanders Peirce

The consciousness of a general idea has a certain "unity of the ego" in it, which is identical when it passes from one mind to another. It is, therefore, quite analogous to a person, and indeed, a person is only a particular kind of …

It is terrible to see how a single unclear idea, a single formula without meaning, lurking in a young man’s head, will sometimes act like an obstruction … in an artery, hindering the nutrition of the brain, and condemning its victim to …

Few persons care to study logic, because everybody conceives himself to be proficient enough in the art of reasoning already.

The Scientific Attitude and Fallibilism in Philosophical Writings of Peirce, selected and edited with an introducton by Justus Buchler. p. 49