“‘When I use a word,’” said Humpty Dumpty, ‘it means just what I choose it to mean – neither more nor less.’ ‘The question is,’ said Alice, ‘whether you can make words mean so many different things.’”

When it comes to social structure, sociology has been like Humpty Dumpty. Over 20 years ago, in an article well-known among critical realists, I identified four different conceptions of social structure prevalent in sociology. Today, those four conceptions are still very much with us, attesting to a definite stability in the discipline.

Does it matter what we individually call social structure, as long as we each know what we are talking about? Certainly, we cannot legislate meaning, and it is foolish to argue about mere semantics. But more than semantics is at stake. With different conceptions of social structure come different research agendas, emphasizing different aspects of social ontology. As William Sewell insightfully notes, “the term structure empowers what it designates.” Conversely, disempowered is what it ceases to designate.

Consider, as I have noted, that the American culture of poverty debate in the 1960s pitted culture against structure – specifically the opportunity structure – as rival explanations of chronic poverty with rival policy implications. As noted, that debate has recently returned, along with the rival policy implications. But now that on one prominent view – the one in fact favored by Sewell – structure has virtually been devoured by culture or in Margaret Archer's terms conflated with it, how do we even formulate the former opposition? Would-be advocates of a structural view are deprived even of the words with which to speak.

This chapter will revisit the four concepts of social structure I identified some 20 years ago. It will again state the case for the CR conception of social structure against its mainstream rivals. Over the 20 years since that article, mainstream American sociology has not challenged but only ignored the CR view and the case for it. Such is the prerogative of epistemic dominance.

Today, however, the terms of debate are a bit different. New actors have entered the scene and one of the rival views has been amended – although not in a way that alters the CR critique. The critique now can also be put more sharply.