This chapter builds on the argument developed in the previous chapter, which examined the curriculum implications of comparing the ideas of the French sociologist Emile Durkheim and the Russian psychologist Lev Vygotsky. This chapter returns to the contrasts between the two writers but focuses explicitly on their theories of knowledge. It starts from the position that any critical educational theory needs an adequate social theory of knowledge. However, as discussed in Chapter 2, with the notable exception of Basil Bernstein and a number of those who have worked within the framework that he established (Muller 2000; Moore 2004), the sociology of education has a poor track record in addressing this issue. Chapter 2 argued that sociologists of education have tended to reduce the ‘social’ to the activities, interests or beliefs of groups of ‘knowers’. For somewhat similar reasons the broader field of educational studies is characterized by another divide, between those who emphasize the curriculum and those who focus on classroom practice (or pedagogy). As Alex Moore notes in the introduction to his recent book, curriculum studies seems to have been drawn away from ‘fundamental and global questions of curriculum purposes and effects [and] ... the wider relationships between curriculum, society and culture’ (Moore 2006:1).