Wittgenstein and “Tonk”: Inference and Representation in the Tractatus (and Beyond)

Which concept is the more primitive when it comes to the functioning of the logical constants: representation or inference? Via a discussion of Arthur Prior’s famous mock connective “tonk” and a couple of responses to Prior by J. T. Stevenson and Nuel Belnap, it is argued that early Wittgenstein’s answer is neither. Instead, he takes representation and inference to be equally basic and mutually dependent notions. The nature and significance of this mutual dependence is made clear by an investigation into the Tractarian notion of a proposition. It is further argued that even if Wittgenstein later abandoned the Tractarian conception of what a proposition is, he never gave up the idea that inference and representation play interdependent and equally fundamental roles in logic.