INTRODUCTIONSignificant advances have been made by scholars arguing that we should "re-think" ethnicity (Brubaker 2004, Jenkins 2008. In this paper we accept many or most of their cautions but attempt to take a further step. That is, we wish to show that not only has there been a strand of sociology which routinely takes ethnic groups as real and "ethnicity" as a social force, but that there has also been an ethnicising of sociology. Sociologists have come to see societies as structured around "ethnicity"-or society as made up of ethnic groups. The origins of this meta-theoretical shift are not entirely clear, although we must attribute some of this change to the decline of class analysis-which itself needs to be understood. But if we once inhabited a sociology which understated social identities based on notions of ethnicity, or underestimated nationalism, subordinating these things to "class analysis", we now have a class-free sociology in which "ethnic" and other social identities dominate our thinking. This is, therefore, not just a mistake in how we think about "ethnic groups", but a mistake in thinking about "ethnic groups" at all.We are seeking a sociology of power, the state, class relations and inequalities, economic change and social institutions, which are the staples of sociology. We want to show how this kind of classical sociology can be restated in a way that incorporates the uses of social identities, the manner in which social identities are formed and become relevant to social action, and how in some circumstances, the ethnic categorisation of people becomes deeply embedded. This is a sociology which does not start from the idea, for example, that British society is "divided by class, gender and ethnicity", but is grounded in an understanding of global economic and political change and their repercussions for people's survival, the formation of their daily lives, their work, and their neighbourhoods. Within this sociology we know that social identities are formed and reformed, often prompted Journal for the Theory of Social Behaviour 40:1 0021-8308