The many faces of uniformitarianism in linguistics

The notion of uniformitarianism, originally borrowed into linguistics from the earth sciences, is widely considered to be a foundational principle in modern historical linguistics. However, there are almost as many interpretations of uniformitarianism as there are historical linguists who take the time to define the notion. In this paper I argue, following Gould (1965; 1987), that this confusion results from the fact that uniformitarianism as originally proposed in geology is not itself a uniform notion, and permits at least four readings. Only some of these readings involve substantive claims rather than methodological imperatives, and only some of these readings are useful for the study of language change. The weakest conclusion to be drawn is that these distinct notions need to be kept apart when invoked by historical linguists.