Logical Form and Propositional Function in the Tractatus

Wittgenstein's Tractatus carefully distinguished the concept all from the notion of a truth‐function, and thereby from the quantifiers. I argue that Wittgenstein's rationale for this distinction is lost unless propositional functions are understood within the context of his picture theory of the proposition. Using a model Tractatus language, I show how there are two distinct forms of generality implicit in quantified Tractatus propositions. Although the explanation given in the Tractatus for this distinction is ultimately flawed, the distinction itself is a genuine one, and the forms of generality that Wittgenstein indicated can be seen in the quantified sentences of contemporary logic.