Single Idea 12180

[catalogued under 10. Modality / A. Necessity / 6. Logical Necessity]

Full Idea

There will be a legitimate notion of 'logical' necessity only if there is a notion of necessity which attaches to the claim, concerning a deductively valid argument, that if the premisses are true then so is the conclusion.

Gist of Idea

Logical necessity requires that a valid argument be necessary


Ian McFetridge (Logical Necessity: Some Issues [1986], 1)

Book Reference

-: 'Aristotelian Society' [], p.136

A Reaction

He quotes Aristotle's Idea 11148 in support. Is this resting a stronger idea on a weaker one? Or is it the wrong way round? We endorse validity because we see the necessity; we don't endorse necessity because we see 'validity'.

Related Idea

Idea 11148 Deduction is when we suppose one thing, and another necessarily follows [Aristotle]