This chapter seeks to understand how radical sociologies of school knowledge can be socially identified and understood in relation to mainstream educational research. The chapter considers how the conceptual categories of the field's theoretical propositions can be seen as mental structures which correspond to multiple contexts within the social structures that intersect in and overlap with the field. It analyzes how these varied radical discourses identify themselves, what the logic of their social struggles might be, and how they can be viewed as manifest mental structures within the social structures of the US educational research "community". On a general level, the conceptual dispositions upon which these radical discourses have been constructed are understandable simply by considering what it means to be doing "oppositional" intellectual work in US education. The chapter discusses the relation between these radical discourses and mainstream educational research more clearly.