The second chapter is Russell’s response to idealism understood as an answer to the question of the existence of matter rather than to a question about its nature. (His response to idealism in the latter sense appears in ch. 4.) Chapter 2 is structured as a discussion of a series of arguments for the existence of matter with comments on the strength of each. Try to formulate these arguments for yourself and decide whether you agree with Russell’s evaluation of them. Pay special attention to his remarks at the end of the chapter about instinctive belief and the role of philosophy.

Russell’s chs. 3 and 4 address the second of the questions associated with idealism (see ¶¶1.9-1.11), the nature of external objects. Ch. 3 presents his view and ch. 4 considers arguments for idealism. If the key philosopher in the background of chs. 1 and 2 was Descartes, the one Russell most often has in mind here is Berkeley. In ch. 3, Russell supports Berkeley’s extension of the views of Descartes and Locke concerning “secondary qualities” (i.e., color, sound, etc.) to Locke’s “primary qualities” (i.e., number, size, shape, etc.); and, in ch. 4, it is Berkeley’s idealism that Russell is concerned to reject.

• The heart of ch. 3 is the distinction between real and apparent space and the relation between the two, but you should think also about Russell’s positive account of what we can know about external objects (see ¶¶3.9-3.12).

• In working through ch. 4, think about the two arguments for idealism that Russell considers (beginning with ¶¶4.4 and 4.12, respectively) and his criticisms of these arguments. Russell is probably interested in idealism in part in order to motivate the distinctions he makes in criticizing these arguments. The act/object distinction used in discussing the first has medieval origins but you’ve encountered it already in Russell as the distinction between sensations and sense data in ch. 1 (see ¶1.10). The second set of distinctions, one between knowledge of things and knowledge of facts and another between knowledge of things “by acquaintance” and knowledge of them “by description,” counts as one of the two or three most important ideas in Russell’s book.