Manifest invalidity

Neil Tennant's new argument for intuitionism

Jon Cogburn

pp. 353-362

in: Synthese 134 (3), 2003.

Abstract

In Chapter 7 of The Taming of the True, Neil Tennant provides a new argument from Michael Dummett's ``manifestation requirement'' to the incorrectness of classical logic and the correctness of intuitionistic logic. I show that Tennant's new argument is only valid if one interprets crucial existence claims occurring in the proof in the manner of intuitionists. If one interprets the existence claims as a classical logician would, then one can accept Tennant's premises while rejecting his conclusion of logical revision. Thus, Tennant has provided no evidence that should convince anyone who is not already an intuitionist. Since his proof is a proof for the correctness of intuitionism, it begs the question.

Cited authors

Dummett Michael

Tennant Neil