This is a new edition of the first volume of G.P.Baker and P.M.S. Hacker's definitive reference work on Wittgenstein's Philosophical Investigations. * New edition of the first volume of the monumental four--volume Analytical Commentary on the Philosophical Investigations. * Takes into account much material that was unavailable when the first edition was written. * Following Baker's death in 2002, P.M.S. Hacker has thoroughly revised the first volume, rewriting many essays and sections of exegesis completely. * Part One -- the Essays -- now includes two completely new essays: a Meaning and Usea and a The Recantation of a Metaphysiciana . * Part Two -- Exegesis 1--184 -- has been thoroughly revised in the light of the electronic publication of Wittgenstein's Nachlass, and includes many new interpretations of the remarks, a history of the composition of the book, and an overview of its structure. * The revisions will ensure that this remains the definitive reference work on Wittgenstein's masterpiece for the foreseeable future.