 The book is about philosophy in another sense, since it employs and illuminates some ideas from earlier philosophers, especially Hume and Wittgenstein, and reveals Strawson’s very deep understanding of them. The book marks, also, a further development in Strawson’s engagement with epistemological scepticism. Strawson expresses agreement with some of his earlier critics (in particular Stroud) that transcendental arguments are problematic as anti-sceptical devices, and suggests instead that scepticism can be set aside because no-one is persuaded by sceptical arguments. Philosophical sceptical doubts are not serious doubts, and so are not to be taken seriously. This further twist in Strawson’s epistemology has, again, inspired considerable debate, and no consensus has yet emerged. In particular, it remains to be determined how strongly we should take Strawson’s suggestions that certain claims are presuppositions on human thought and enquiry. One worry which remains is that Strawson’s point that no one is remotely inclined to accept the sceptic’s claim establishes at most that we regard such arguments as having the status of defending a paradoxical conclusion; it does not, in itself, explain why the conclusion is incorrect. However, as well as being an original contribution to epistemology, the book presents an approach to ontology which deserves to be called Oxonian, because it has been popular in Oxford. The idea is that there is no good reason not to be realists about most aspects of the world, including colour, mentality, meaning, and perhaps value, but that this does not require the defence of a reduction to some features of a supposedly more fundamental realm. This is a relaxed realism that does not set its face against the claims of natural science, but rather refuses to take them as calling into question the legitimacy of our ordinary ways of thinking about the world. This form of Oxford realism was influential on a generation of British philosophers, many of whom were Strawson’s students.