Maggs Bros.

The work develops the distinction between object language and meta-language that was characteristic of Hilbert’s formalism. It also introduces Carnap’s distinction between language used in the material mode and in the formal mode. In the material mode, sentences which appear to be about things in the world are in fact syntactical, formal sentences about language. ‘One purpose of this book, in opposition to the view attributed to Wittgenstein, was to show that a language could significantly be used to express its own syntax. Another was to make good Carnap’s claim that philosophy, to the extent that it could be a cognitive discipline, had to consist in the logic of science, which was itself. identified with the logical syntax of a scientific language’ (A. J. Ayer).

‘This exceptionally complex work attempted to carry out the positive part of the program sketched in ‘The Overcoming of Metaphysics by the Logical Analysis of Language.’ Metaphysics having been eliminated, and the very word philosophy having been gotten rid of (as Neurath wished), it remained to reconstruct the ‘logic of science’ - the syntax of scientific language - that was to replace metaphysics. Because syntactic propositions, no less than logical propositions, needed to be rigorously analysed, the syntax had to be elaborated in terms of the language of science itself. This is the task Carnap sets for himself at the beginning of the book’ (Delacampagne, p. 109).