This paper contributes to the critical engagement about educational development and its status as a field. The critique focuses in particular on our knowledge and the nature of our knowledge-building. The paper argues that unless we strengthen our knowledge base we will not emerge as a professional field able to engage rigorously and systematically with the problems of higher education. Drawing on social realist work that builds on the ideas of Basil Bernstein, a framework is offered for conceptualizing knowledge differentiation and the implications of different types of knowledge for knowledge-building. The paper concludes with suggestions on how educational development might strengthen its knowledge-building capacity. (Contains 4 notes and 3 figures.)