more from Peter van Inwagen

Single Idea 17587

[catalogued under 5. Theory of Logic / D. Assumptions for Logic / 2. Excluded Middle]

Full Idea

I think the validity of the 'Law' of Excluded Middle depends on the assumption that every proposition is definitely true or definitely false.

Gist of Idea

The 'Law' of Excluded Middle needs all propositions to be definitely true or definitely false


Peter van Inwagen (Material Beings [1990], 18)

Book Reference

Inwagen,Peter van: 'Material Beings' [Cornell 1995], p.262

A Reaction

I think this is confused. He cites vagueness as the problem, but that is a problem for Bivalence. If excluded middle is read as 'true or not-true', that leaves the meaning of 'not-true' open, and never mentions the bivalent 'false'.

Related Idea

Idea 9024 Excluded middle has three different definitions [Quine]