 In other words, far from being inevitable, the emergence, towards the end of the 1930s, of first-order logic as a privileged system of logic depended on two things, each independent of the other. On the mathematical side, it depended on Hilbert’s introduction of metalogical techniques; on the philosophical side, it depended on the arguments of the Grundlagenkrise. Neither of these things was inevitable: nor was the fact that they occurred at roughly the same time. With a different history, Hilbert’s flexible attitude might have prevailed, and there might have been more emphasis on higher-order systems, or on the exploration of algebraic logics, infinitary logics, category-theoretic systems, and the like: in short, on logical pluralism. 