“All philosophy is ‘critique of language’” Wittgenstein wrote in the Tractatus Logico-Philosophicus, but also: “All the sentences of our ordinary language are indeed, just as they are, logically completely ordered” (TLP 4.0031, 5.5563). Taken together, these two remarks appear contradictory at first. The contradiction vanishes, however, when we come to understand that “critique” is something very different from criticism or the attempt to find fault. Instead, the notion of critique belongs to the tradition of critical philosophy, a tradition founded by Immanuel Kant. In this tradition, philosophical critique examines human language or reason to determine its implicit presuppositions, its capacities, its limits. From such a critique of language emerges Wittgenstein's verdict that the sentence “France lies to the south of England” is perfectly good, while “Murder is evil” is nonsense.

Before reconstructing the argument that led to Wittgenstein's conclusion, this chapter will consider its motivation, which is rooted in the critical tradition. We will see that the critique of language and reason is always also a critique of metaphysics. It claims a middle ground between dogmatism and skepticism. Dogmatism establishes and defends metaphysical doctrines in a manner that ultimately glosses over rather than answers the questions of philosophy. Skepticism abandons all hope that these questions can ever be answered. It therefore fails to offer a satisfactory explanation of how our ordinary lives can proceed as easily as they do and without being haunted by the unanswered questions.