This Introduction provides summaries of the chapters of the book and briefly discusses some of the main obstacles we encounter when we attempt to engage with Wittgenstein’s Tractatus.

This chapter examines Heidegger’s use of seemingly nonsensical sentences in his 1926 Logic lectures to illustrate the primacy of a kind of practical sense, which serves as a basis for a derivative logical-propositional sense. It contrasts Heidegger’s approach with a conception of nonsense emerging out of an “austere” reading of Wittgenstein’s Tractatus, according to which nonsense is never a function of what words mean but only a result of a failure to assign a meaning to one or more elements of a would-be proposition; according to this austere reading, there are thus no nonsensical propositions, but only strings of meaningless signs. Although Heidegger in certain respects hews to this austere conception, viz. in recognizing the interplay between bipolarity and something’s being a proposition at all, his use of nonsense nonetheless departs from the specifics of the austere reading. Doing so, the chapter argues, allows Heidegger to do a kind of phenomenological-ontological work, whose possibility the austere reading renders obscure (at best).