This book represents a new departure in 'educational psychology.' It is a volume conceived and organized around the practical question. What is known about the nature of mental growth and functioning that might be of use to specialists in education, be they concerned with teaching or curriculum making or evaluation? It is a book at once bold and learned, and it is good that it is both. One final note. Sylvia Farnham-Diggory, in addition to being an able psychologist, is a human being of great zest, with an evident and long term attachment to the working of the human mind, in whatever guise.