Single Idea 13342

[catalogued under 5. Theory of Logic / B. Logical Consequence / 1. Logical Consequence]

Full Idea

Carnap proposed to define consequence as 'sentence X follows from the sentences K iff the sentences K and the negation of X are contradictory', but 1) this is intuitively impossible, and 2) consequence would be changed by substituting objects.

Gist of Idea

Carnap defined consequence by contradiction, but this is unintuitive and changes with substitution

Source

comment on Rudolph Carnap (The Logical Syntax of Language [1934], p.88-) by Alfred Tarski - The Concept of Logical Consequence p.414

Book Reference

Tarski,Alfred: 'Logic, Semantics, Meta-mathematics' [Hackett 1956], p.414


A Reaction

This seems to be the first step in the ongoing explicit discussion of the nature of logical consequence, which is now seen by many as the central concept of logic. Tarski brings his new tool of 'satisfaction' to bear.