Originally published in 1988, The Mastery of Reason is, on one level, a study of children’s cognitive development. It engages with debates about the ‘individual’ and the ‘social context’ in accounts of children’s mathematical development at the time. However, Valerie Walkerdine seeks to go beyond these debates to establish the empirical and theoretical base for a different kind of understanding of the social and psychological production of reason and rationality. She does so by presenting empirical material concerning children’s learning of mathematics, both at home and in the early years of schooling. The book is packed with fascinating inter-changes between mothers or teachers and children. However, an analysis of the apparently innocent subject of children’s mathematical development can also offer profound and disturbing insights into the way in which our bourgeois democracy is maintained. Valerie Walkerdine shows how notions of rationality and the triumph over unreason, which are encouraged in the teaching of mathematics, are an early induction into the fantasy of control over a calculable universe, necessary to sustain our present social and political order. This book is unique in its relevance both to educational practice and to psychological and social theory. It is an important contribution to the literature available to students of developmental and social psychology, sociology, social theory, and education.