a priori, and what is more, to a rejection based ultimately on a
posteriori findings; in other words, the "pure" science of nature in
Kant's sense of the term had proved to be, not only not pure, but even
false. As for logic and mathematics, the decisive works of Frege,
Russell, and White- head suggested two conclusions: first, that it was
possible to construct mathematics on the basis of logic (logicism), and
secondly, that logical propositions had an irrevocably analytic status.
But within the frame- work of logicism, the status of logical
propositions is passed on to mathematical ones, and mathematical
propositions are therefore also conceived of as analytic. All this
creates a situation where the existential presupposition contained in
the Kantian question about the possibility of judgements that are both
synthetic and a priori must, it seems, be rejected as false. But to drop
this presupposition is, at the same time, to strike at the very core of
Kant's programme of putting the natural sciences on a philosophical
foundation. The failure of the modern attempt to do so suggests at the
same time a reversal of the relationship between philosophy and the
individual sciences: it is not the task of philosophy to meddle with the
foundations of the individual sciences; being the less successful
discipline, its task is rather to seek guidance from the principles of
rationality operative in the individual sciences.