This book offers an original reading of Wittgenstein's views on such topics as radical scepticism, the first- and third-person asymmetry of mental talk, Cartesianism, and rule-following.The celebrated 20th century philosopher, Ludwig Wittgenstein, developed an interest in his later career in natural forms of behaviour and the role they play in our linguistic and other intellectual practices. To many, Wittgenstein appears to be advancing a theory about these practices as originating in natural forms of behaviour. However, theories of this sort seem out of place in philosophy, especially in light of Wittgenstein's own expressed views on the purpose of philosophy.Keith Dromm offers a way of understanding these apparently incongruous aspects of Wittgenstein's writings that is more consistent with his views on the proper purpose of philosophy. The book shows that Wittgenstein does not in fact offer theories about natural human behaviour. Rather, these references belong to a type of philosophical reasoning that is not meant to contribute to our knowledge, as explanations in science do, but instead to help clarify our thinking on certain philosophical topics. In particular, they serve to relieve apparent tensions between the things we do know.