Education in countries such as New Zealand, the United Kingdom, Austra- lia, Canada, and South Africa has been influenced since the late 1970s by progressive educators’ commitment to the “social construction” approach to curriculum knowledge. This commitment brings with it a focus on what children already know. Instead of the disciplinary knowledge based on universal principles and methods, the school curriculum emphasises knowledge constructed from students’ experiences. The consequences of the constructivist influence are profound. Without access, or with limited access, to the concepts, methods, and literacies of disciplinary knowledge in the arts, sciences, and humanities, young people are unable to develop the conceptual tools required for advanced intellectual activity. It is not only that many young people miss out on the content of those disciplines— although that itself is a serious problem—more important, they are denied the means to acquire the principles, concepts, and processes that enable deep understanding of the natural and social worlds.