Single Idea 14108

[catalogued under 5. Theory of Logic / B. Logical Consequence / 8. Material Implication]

Full Idea

It would be a vicious circle to define material implication as meaning that if one proposition is true, then another is true, for 'if' and 'then' already involve implication.

Gist of Idea

It would be circular to use 'if' and 'then' to define material implication

Source

Bertrand Russell (The Principles of Mathematics [1903], §037)

Book Reference

Russell,Bertrand: 'Principles of Mathematics' [Routledge 1992], p.33


A Reaction

Hence the preference for defining it by the truth table, or as 'not-p or q'.