This essay explores the interplay between educational and architectural methodologies for analysing the school environment. It historicises the affinity between architectural and educational practices and modes of knowledge pertaining to the child's body during the period of postwar reconstruction in England to argue that educational spaces were designed to accommodate the child's free movement and bring it under observation, in order to constitute an active and emotionally adjusted citizen. Drake and Lasdun's Hallfield Primary School is studied to illustrate the architectural implications of the shift in the modes of knowledge defining the child as an active and emotive subject, in part by aestheticising the sensation of movement. Thus the essay expands upon Andrew Saint's seminal account by reinterpreting the architecture of the postwar school as a social technology, and identifying a pragmatist current of modernist architecture that was influenced by the concepts of time and growth developed independently by Alfred North Whitehead and Herbert Read. (Contains 6 figures and 47 footnotes.)