ExtractS. Seth Bordner Berkeley is famous for his immaterialism and for his idealism. Let us define immaterialism as the denial that there is anything answering to the name ‘matter’, and idealism as the view that, fundamentally, everything that exists is either a mind or in a mind. These are somewhat unorthodox definitions, in part because they separate two ideas that are sometimes blended together. A recent book on Berkeley defines immaterialism as ‘the view that only minds and ideas exist; there is no such thing as matter’ (Dicker 2011, 3) . But it is important, I think, to keep these views separate. What counts as an argument that there is no such thing as matter does not show anything with regard to whether everything is a mind (or in a mind) , or even whether anything is a mind (or in a mind) . This distinction is also useful for...