 The idea had of course been suggested by Hilbert’s “method of bifurcation [Methode der Zweiteilung]” as Carnap had called it, distinguishing a meta-mathematics with concrete meaning, on the one hand, from mathematics proper, on the other, which was to be regarded as purely formal, and the formal properties of which (e.g., consistency) Hilbert had aimed to study and prove in meta-mathematics—a method which Carnap sought to extend from mathematics to the whole of knowledge. The “chief motivation for my development of the syntactical method”, Carnap later wrote, was this: