Chapter 11 begins the final section of the book, in which Russell considers the way our knowledge is built on its foundations. This chapter continues a discussion of intuitive knowledge that Russell begins at the end of ch. 10 and that he will return to in ch. 13.

• The argument for necessity of intuitive knowledge that begins the chapter (¶¶11.1-11.2) can be traced back to Aristotle but it has been questioned, especially in recent decades. Views resting on this sort of argument would now be labeled foundationalism and after midsemester we will consider criticisms of a couple sorts of foundationalism.

• After a brief survey of the range of intuitively known general principles (¶¶11.3-11.5), Russell turns to intuitive knowledge derived immediately from perception (¶¶11.6-11.14). His discussion of this is devoted mainly to a somewhat tentative treatment of two sorts of self-evidence—one that precludes error and another that doesn’t—that reflects the difficulty of describing the transition from acquaintance with objects to knowledge of facts. Russell will return to this difficulty in ch. 13 in a way that uses ideas he develops in ch. 12, and we will postpone our discussion of it until then.

Chapter 12, like chapter 5, represents an original contribution by Russell and, also like chapter 5, it contains material from a separately published paper. The ideas it presents had a nearly immediate impact on the history of analytic philosophy, for the criticism of them was at the heart of Wittgenstein’s early work. Russell here is trying to locate himself between two contemporary positions.

• The first (represented by the British idealists) rejected an independent reality as the basis for the truth or falsity of our thoughts and developed an alternative conception of truth as “coherence.” Russell’s list of requirements for any theory of truth (¶¶12.3-12.11) constitutes an attack directed at this approach.

• The second position Russell rejects was an extreme realism (centered in Austria before WWI—with Alexius Meinong as its best-known exponent). Its proponents held that any object of thought must have some reality and extended this to such self-contradictory objects as round squares. Russell’s concerns with this view (expressed on ¶¶12.14-12.15) lead him to reject also the more moderate view (held, for example, by Frege) that belief, true or false, was a relation between a person and the content of the belief, which might be expressed by a that-clause (see ¶¶12.15 and 12.17).

The remainder of the chapter (¶¶12.17-12.23) presents Russell’s way around these two views and explains the talk of “constituents” of the judgments that you have encountered from time to time in earlier chapters. Although these issues were contemporary ones for Russell, they are as old as Western philosophy: Russell is, in effect, responding to Parmenides’s claim that not-being is unthinkable, and his response might be compared to the one given by Plato in the Sophist. Russell’s solution was rejected by Wittgenstein, and Wittgenstein’s arguments were enough to shake Russell’s confidence in it. It is Wittgenstein’s search for an alternative to Russell’s views here that led to the further development of analytic philosophy.