It is the autumn of 1910, and Ferdinand de Saussure has embarked on a series of lectures on general linguistics for the third time. He begins with the by now familiar point that the object of linguistics should not be the faculty which we all possess as individuals–the ‘faculty which can be called the faculty of articulated language’–but the social institution, the language system, that allows us to make use of this faculty. 1 But there is a problem for linguists: there is not simply a language system, there are many. ‘What is given’, he says, ‘is not only the language [la langue], but languages [les langues]’ (Third Course 9a.). And ‘[a]s far as linguistics is concerned, the diversity of languages is indeed the fundamental fact’ (Third Course 12a). This fundamental fact was the focal point for linguists in the nineteenth century, who misunderstood it more or less completely. The scholars who created the discipline of comparative philology spared no effort in describing and mapping this diversity, which they thought about with the help of some colourful organic metaphors. The different languages were like people or animals, in that they had a birth, maturation, and death; they had kith and kin, being grouped in families of languages–Indo-European, Semitic, Finno-Ugric–and their evolution could be diagrammed as a tree, with a parent trunk and several diverse branches. And, of course, many of them associated the most vigorous (and to their mind the most successful) branches of the family tree with particular peoples or races whose superiority was manifest in what was often called the ‘genius’ of their language, the elegance of its inner logic.