Properties Ain’t No Puzzle

Frege’s Commitment Puzzle concerns inferences from sentences such as “Jupiter has four Moons” to sentences such as „The number of moons of Jupiter is four”. Although seemingly about completely different things, such pairs of sentences appear to be truth-conditionally equivalent. In this paper, I make a case against versions of the Puzzle that appeal to properties and propositions. First, I argue that propositions in Frege’s biconditionals serve a specific, non-referring conversational role. Second, I claim that the existence of properties derived from Frege’s equivalences relies on a controversial philosophical premise. Third, I contend that it takes more than conversational interchangeability for two sentences to be equivalent and that genuine equivalence has not been established for non-numerical versions of Frege’s biconditionals. I conclude by suggesting that, being restricted to numbers, the Commitment Puzzle may be classified as a local oddity.