Single Idea 13635

[catalogued under 5. Theory of Logic / K. Features of Logics / 3. Soundness]

Full Idea

A logic is 'weakly sound' if every theorem is a logical truth, and 'strongly sound', or simply 'sound', if every deduction from Γ is a semantic consequence of Γ. Soundness indicates that the deductive system is faithful to the semantics.

Gist of Idea

'Weakly sound' if every theorem is a logical truth; 'sound' if every deduction is a semantic consequence

Source

Stewart Shapiro (Foundations without Foundationalism [1991], 1.1)

Book Reference

Shapiro,Stewart: 'Foundations without Foundationalism' [OUP 1991], p.8


A Reaction

Similarly, 'weakly complete' is when every logical truth is a theorem.