This article discusses the work of Susan Isaacs (1885-1948), the IOE's (Institute of Education), first director of the Department of Child Development. In addition to introducing child psychoanalysis to the UK, Isaacs was instrumental in mapping out the basis for a conceptual understanding of the role of aspects of imagination (which she termed 'phantasy') and play in the life of children. This allowed early childhood educators to develop holistic pedagogies that embraced both the intellectual and the social development of children. Her work has provided the basis for contemporary professional practice within the sector.