Modern Continental philosophy had always maintained close ties with scientific developments. In Kant the link became so close that the whole doctrine of the a priori had been motivated largely by a datum that had emerged from the sciences – an allegedly transparent feature of geometry, arithmetic, and the calculus that demanded philosophical explanation. Kant's successors in the nineteenth century were of two types: those who wanted to check whether what he said about the a priori sciences was true and those who didn't really care. The latter embraced his Copernican turn for “metaphysical” reasons. The former, by and large, devoted a great deal of time to an analysis of mathematical knowledge. As a result, their more gullible colleagues tended to look on them as lowlevel mathematicians trying to make a reputation in philosophy. “Mathematica sunt, non leguntur” is what Frege once guessed most philosophers would say about his writings. He was right. The same could have been said of the major writings of the semantic tradition.

The semantic tradition may be defined by its problem, its enemy, its goal, and its strategy. Its problem was the a priori; its enemy, Kant's pure intuition; its purpose, to develop a conception of the a priori in which pure intuition played no role; its strategy, to base that theory on a development of semantics.