Abstract

In this paper I examine two substantial interpretations of Wittgenstein’s criticisms of Frege’s conception of logic. One is based on Frege’s rejection of psychologism and alleges that this rejection engenders a tension that is resolved in the Tractatus. The other is based on the claim that there are patterns of inference involving what are now known as propositional attitude ascriptions that Frege’s conception of logic is not equipped to handle. I show that neither of these interpretations present a compelling criticism of Frege. I then argue that Wittgenstein inherited from Frege the ideas of affirmation, denial, and the “opposite” of a thought, but came to see that these conflict with Frege’s conception of negation as a truth-function. This leads to the Grundgedanke of the Tractatus: neither negation nor any other “logical constant” is a representative in our picturing of the world.