Criticism of the Verification Principle in A.J. Ayer's Book Language, Truth and Logic

Criticism of the Verification Principle in A.J. Ayer's Book Language, Truth and Logic

INTRODUCTION

This essay will consist in an exposition and criticism of the Verification Principle, as expounded by A.J. Ayer in his book Language, Truth and Logic. Ayer, wrote this book in 1936, but also wrote a new introduction to the second edition ten years later. The latter amounted to a revision of his earlier theses on the principle.It is to both accounts that this essay shall be referring.

Firstly, I shall expound the verification principle. I shall then show that its condition of significant types is inexhaustible, and that this makes the principle inapplicable. In doing so, I shall have exposed serious inconsistencies in Ayer's theory of meaning, which is a necessary part of his modified verification principle.

I shall also expound Ayer's theory of knowledge, as related in his book. I will show this theory to contain logical errors, making his modified version of the principle flawed from a second angle.

The relationship of this essay with the two prior essays of this series can be understood from Ayer's Preface to the First Edition of his book:

The views which are put forward in this treatise derive from the doctrines of Bertrand Russell and Wittgenstein.

For background interest, Language, Truth and Logic was written after Ayer had attended some of the meetings of the Vienna Circle, in the 1930's.

Friedrich Waismann and Moritz Schlick headed these logical positivists of Vienna. Their principle doctrine can be said to have been founded in the meetings they had with Wittgenstein and their interpretation of his Tractatus Logico-Philosophicus.

Ayer's book expounds and, in his view, improves on the principle doctrine of the Vienna Circle 'the verification principle'. Waismann and Schlick adopted this principle after it was first given to them by Wittgenstein himself.

Waismann recorded the conversation, where Wittgenstein stated:

If I say, for example, 'Up there on the cupboard there is a book', how do I set about verifying it? Is it sufficient if I glance at it, or if I look at it from different sides, or if I take it into my hands, touch it, open it, turn its leaves, and so forth? There are two conceptions here. One of them says that however I set about it, I shall never be able to verify the proposition completely. A proposition always keeps a back door open, as it were.