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. 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 found in Plato’s 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. Russell himself was among the first to be influenced by Wittgenstein’s work. He called the position he came to adopt “logical atomism,” but that label is even more apt for the view he adopts here.