A Revolution in Logic?

Abstract

Logic might at first sight seem an unlikely arena for revolutions, even for revolutions in Jefferson’s sense rather than Lenin’s. Kant maintained that Aristotelian logic had not changed in two thousand years and could never change.1 Even though Kant’s view of Aristotle’s logic has been thoroughly discredited (even by Aristotle’s own standards) both systematically and historically,2 most contemporary philosophers and linguists are adopting the same Kantian attitude to Frege’s logic, or strictly speaking rather to that part of Frege’s logic that has come to be known variously as first-order logic, quantification theory, or lower predicate calculus. When a critic once suggested to a prominent philosopher of language that one of the cornerstones of ordinary first-order logic, Frege’s treatment of verbs for being like is, does not capture the true Sprachlogik, he looked at the speaker with an expression of horror — mock horror, we hope — and said, “Nothing is sacred in philosophy any longer!”