Abstract

In this note I argue that, relative to certain largely uncontroversial background conditions, any instance of Mates' Puzzle is equivalent to some instance of Frege's Puzzle. If correct, this result is surprising. For, barring the radical move of rejecting the possibility of synonymous expressions in a language tout court, it shows that there is no strictly lexical solution to at least some instances of Frege's Puzzle. This forces the hand of theorists who wish to provide a semantic (rather than pragmatic) solution to Frege's Puzzle. The only option open will be modify in one way or another the standard formulation of semantic compositionality.