One of the fundamental questions on which we linguists disagree is whether or not our subject is useful for education. On one side is a long tradition, stretching back to the classical world, in which the practical benefits were clear and agreed – for example, the early Stoic grammarians aimed to improve literary style (Robins 1967: 16), and the Latin grammarians wrote pedagogical texts for use in school (ibid.: 54). In modern times this tradition is represented by leading linguists such as Tesnière (1959) and Halliday (1964), whose work has been motivated at least in part by the desire to improve language teaching at school. On the other hand is an equally long philosophical tradition of ‘pure’ scholarship for its own sake, in which the only motivation was a desire to understand language better. Recently this tradition is most clearly represented by two linguists who otherwise have little in common, Sampson (1980) and Chomsky (Olson, Faigley & Chomsky 1991), both of whom have denied that linguistics has, can have or indeed should have any relevance to language teaching.The aim of this paper is to defend the traditional idea that linguistics has an important contribution to make in language teaching, though I shall not of course suggest that every piece of academic research should have a clear pay-off in terms of practical benefits. ‘Blue-skies’ research is just as important in linguistics as in other disciplines. All I shall argue is that our discipline, seen as a whole, has an important interface with education, and that research whose results cross this interface is just as important as that which feeds into, say, neuroscience or child development. Indeed, I shall go further by arguing that academic linguistics is weakened if we ignore the impact of education on language, so information must cross this interface in both directions. If the interface is important even for ‘pure’ research, it follows that we cannot simply name it ‘applied linguistics’ and leave it to those who call themselves applied linguists. My point is that the debate is relevant to all linguists, however ‘pure’, because if education has a profound impact on language, we should know rather better than we do at present exactly what that impact is.