more from Stephen Read

Single Idea 10986

[catalogued under 5. Theory of Logic / A. Overview of Logic / 5. First-Order Logic]

Full Idea

We must recognise that first-order classical logic is inadequate to describe all valid consequences, that is, all cases in which it is impossible for the premisses to be true and the conclusion false.

Gist of Idea

Not all validity is captured in first-order logic


Stephen Read (Thinking About Logic [1995], Ch.2)

Book Reference

Read,Stephen: 'Thinking About Logic' [OUP 1995], p.54

A Reaction

This is despite the fact that first-order logic is 'complete', in the sense that its own truths are all provable.