more from Charles Chihara

Single Idea 9552

[catalogued under 5. Theory of Logic / K. Features of Logics / 2. Consistency]

Full Idea

In first-order logic a set of sentences is 'consistent' iff there is an interpretation (or structure) in which the set of sentences is true. ..For Frege, though, a set of sentences is consistent if it is not possible to deduce a contradiction from it.

Gist of Idea

Sentences are consistent if they can all be true; for Frege it is that no contradiction can be deduced


Charles Chihara (A Structural Account of Mathematics [2004], 02.1)

Book Reference

Chihara,Charles: 'A Structural Account of Mathematics' [OUP 2004], p.33

A Reaction

The first approach seems positive, the second negative. Frege seems to have a higher standard, which is appealing, but the first one seems intuitively right. There is a possible world where this could work.