Abstract

The article presents a detailed consideration of the arguments from the symposium “Verifiability”, which was held on July 14, 1945 in London, proposed by Scottish philosopher and theologian Donald MacKinnon, Austrian logician and mathematician Friedrich Waismann and English logician and philosopher of science William Kneale. MacKinnon’s approach to verifiability was based on the metaphysics of fact, while Waismann and Kneale’s approach was based on the semantic specificity of empirical concepts (“open texture” and context of use) and on the truth-values of empirical propositions. The symposium in question is interesting primarily because it is the last meaningful discussion on the concept of verifiability in the form in which it was understood by the Vienna Circle. Despite the fact that, in the coming years, this concept received a completely different interpretation, which stands away from the original source, the 1945 symposium could be rightfully treated as a canonical discussion on verifiability in the sense that nothing like this has ever happened in the philosophy after.