An essential resource for students of Wittgenstein, this collection contains faithful, in some cases expanded and corrected, versions of many important pieces never before available in a single volume, including Notes for the 'Philosophical Lecture', published here for the first time. Fifteen selections, with bi-lingual versions of those originally written in German, span the development of Wittgenstein's thought, his range of interests, and his methods of philosophical investigation. Short introductions, an index, and an updated version of Georg Henrik von Wright's The Wittgenstein Papers situate the selections within the broader context of the Wittgenstein corpus and the history of its publication.