Despite the impression we may have of an almost uninterrupted development of the European ratio from the Renaissance to our own day, despite our possible belief that the classifications of Linnaeus, modified to a greater or lesser degree, can still lay claim to some sort of validity, that Condillac's theory of value can be recognized to some extent in nineteenth century marginalism, that Keynes was well aware of the affinities between his own analyses and those of Cantillon, that the language of general grammar (as exemplified in the authors of Port Royal or in Bauz e) is not so very far removed from our own