Ayer’s Language, Truth, and Logic is a short book, and you will be reading a substantial part of it. It was written in 1935 under the influence of logical positivism and less than a decade after that movement appeared on the scene. The selections in Klemke do not divide easily into two classes, and your reading assignments are unequal, so our discussion of Tuesday’s topics may continue into Thursday’s class. However, I will suggest two main topics for each class.

The overall focus of the first group of selections is the nature of philosophy. In ch. I, Ayer rejects the possibility of any science of non-empirical truths, and in chs. II-IV he says what he thinks philosophy should be. You will read all of chs. I and IV and part of ch. II (ch. III is concerned with Ayer’s views about the nature of philosophical analysis).

•  The basis on which Ayer rejects metaphysics in ch. I (Klemke, pp. 180-192) is the “criterion of verifiability.” This is the most characteristic doctrine of the logical positivists. It was advocated by Wittgenstein, too, around 1929-1930 at a time when he was in regular conversation with Moritz Schlick and other members of the Vienna Circle; and he may have been the origin of the idea in the form in which the logical positivists developed it (though its roots can be traced back at least to Hume). The specific form of the principle varied from one philosopher to another, and Ayer will describe a couple of versions in the text of ch. I and another in a selection from the second edition of the book (dating from 1946) which Klemke includes with ch. I. You should think about Ayer’s attack on metaphysics but also about the criterion of verifiability in its own right as a condition of meaningfulness. In the latter regard think both about the specific issues that Ayer discusses in connection with the formulation of the criterion but also about the motivation and adequacy of any criterion of verifiability.

•  The selection from ch. II points to a matter of dispute among analytic philosophers. Ayer’s view of philoosophy is close to that of Wittgenstein (at least up to the early 1930s) and the logical positivists. However, the view of analysis that Ayer ascribes to its critics on p. 196 may not have been too far from the view held by Russell, who was never very comfortable with the emphasis that Wittgenstein placed on language. Notice also the idea, due to Rudolph Carnap (another member of the Vienna Circle and perhaps the most important of the logical positivists), that claims about language can appear to be factual (p. 197).

•  Ch. IV is devoted to another characteristic view of the logical positivists, that anything known a priori must be analytic (Ayer will discuss both of these ideas). This is another view that can be traced to Wittgenstein, in this case to the Tractatus Logico-Philosophicus (the work he wrote during WWI).

I’ll suggest we focus our discussion Tuesday on the key ideas of chs. I and IV—i.e., on the criterion of verifiability and on the claim that anything known a priori is analytic.