The principal purpose in preparing a second edition of the Guidebook to Wittgenstein’s Philosophical Investigations is to provide an exposition of remarks that were not covered in the first edition. Two additional chapters (Chapter 6 and Chapter 7) on intentional concepts – thinking, imagining, believing, expecting and intending – expand the interpretation to cover remarks up to §693 of the Philosophical Investigations (formerly Part I). The result does not amount to a commentary on the whole of Wittgenstein’s text – in particular, §§39–88, in which he discusses simples and the idea of family resemblance, are not covered – but it does provide an exposition of a significant proportion of his remarks, covering the majority of the concepts he investigates. In addition to extending the coverage to include intentional concepts, I have also added a section on the notion of criteria (Chapter 5), and have expanded the discussion of rule-following to include an account of some of the interpretative issues that have arisen in the wake of the publication of Saul Kripke’s book, Wittgenstein on Rules and Private Language (Chapter 3).
In making these extensions, I have tried to stick to the approach of the first edition that set out to follow the details of the dialectical process by which Wittgenstein aims to clarify the way our concepts function. I hope that the result brings out stillmore clearly both the profound unity of the work and the fundamental shift that Wittgenstein aims to bring about in our understanding of how language functions, and more generally of the way we operate with psychological expressions. Although the interpretation I develop emphasizes the idea of a grammatical investigation of our concepts, and resists the claim that Wittgenstein’s aim is to refute philosophical theses or prove what must be the case, it nevertheless serves to reveal that one of the fundamental themes of his remarks is to show that the idea that psychological expressions function as descriptions of events and processes occurring in an inner realm is an illusion. The extension of the interpretation to cover intentional concepts, including the discussion of Moore’s Paradox in section x of Philosophy of Psychology – A Fragment (formerly Part II), and the remarks on the use of the first person pronoun, serves, I hope, to bring out the continuing significance of Wittgenstein’s approach.