Single Idea 11059

[catalogued under 2. Reason / F. Fallacies / 4. Circularity]

Full Idea

A circular argument - one whose conclusion is to be found among its premises - is inadmissible in most informal contexts, even though it is formally valid.

Gist of Idea

Circular arguments are formally valid, though informally inadmissible

Source

Robert Hanna (Rationality and Logic [2006], 2.1)

Book Reference

Hanna,Robert: 'Rationality and Logic' [MIT 2006], p.31


A Reaction

Presumably this is a matter of conversational implicature - that you are under a conventional obligation to say things which go somewhere, rather than circling around their starting place.