I am very grateful to Constantine Sandis for asking me to make a collection of my papers on Wittgenstein's later philosophy. It proved the perfect project for the coronavirus lockdown in England, which began in March 2020 and continued more or less for the rest of the year.

I have chosen papers which focus on the themes of scepticism and knowledge and which emphasize and explore the role of naturalism in Wittgenstein's later thought. Central to any interpretation of Wittgenstein's later philosophy is an understanding of his philosophical method, and the nature of the turn which characterizes the evolution from his early to his later work. In these chapters, I argue that the methodological shift has at its heart a highly distinctive form of naturalism. Wittgenstein himself emphasizes this naturalistic turn when he remarks that ‘what we are supplying are really remarks on the natural history of human beings’ (PI §415).

This form of naturalism has nothing to do with the kind of scientific naturalism that is associated with accounting for all phenomena in terms of the conceptual resources of the natural sciences. It is closer to the Aristotelian naturalism defended by John McDowell, although, in Wittgenstein's case, the principal influence is Goethe, whose conception of how to understand the phenomena of nature is self-consciously opposed to the reductive approach of scientific naturalism. Goethe places emphasis on achieving a clarified view of complex, natural phenomena in their natural setting, with the aim of describing patterns and connections that are there in plain sight. The novelty of Wittgenstein's later work is that it applies these methods to the task of conceptual clarification, which aims at dissolving philosophical problems and paradoxes.

The chapters in this volume cover the following topics: scepticism about the external world, scepticism about other minds, knowledge and belief, meaning and rule-following, psychological states and the distinctive first-person use of psychological concepts, the relation between the early and the later philosophy and the nature of Wittgenstein's naturalism.

Chapter One, ‘Wittgenstein on Certainty’, addresses the question whether Wittgenstein's notes collected in OC contain the makings of a philosophically satisfactory response to scepticism about the external world.