David G. Stern

Ludwig Wittgenstein is one of the most important, influential, and often-cited philosophers of the twentieth century, yet he remains one of its most elusive and least accessible. The essays in this volume address central themes in Wittgenstein's writings on the philosophy of mind, language, logic, and mathematics. They chart the development of his work and clarify the connections between its different stages. The contributors illuminate the character of the whole body of work by keeping a tight focus on some key topics: the style of the philosophy, the conception of grammar contained in it, rule-following, convention, logical necessity, the self, and what Wittgenstein called, in a famous phrase, 'forms of life'.

Drawing on recent work on the nature of the numbering system of the _Tractatus_ and Wittgenstein’s use of that system in his composition of the _Prototractatus_, the paper sets out the rationale for the online tool called__ __ The University of Iowa Tractatus Map. The map consists of a website with a front page that links to two separate subway-style maps of the hypertextual numbering system Wittgenstein used in his _Tractatus_. One map displays the structure of the published _Tractatus_; the other lays out the structure of the _Prototractatus_. The site makes available the full text of the German and the two canonical English translations.__ __While we envisage the map as a tool that we would like a wide variety of readers to find helpful, we argue that our website amounts to a radically new edition of Wittgenstein’s early masterpiece, with far-reaching implications for the interpretation of that text. In particular, we claim that our visually compelling presentation of the book’s overall structure delivers on Wittgenstein’s cryptic claim in a letter to his publisher that it is the numbers that “make the book surveyable and clear”.