This book provides both a lost last word and a firm first foundation: seven lectures, given in the last months in the life of the Soviet thinker, teacher, and writer L.S. Vygotsky, offer us the most comprehensive and developed form of his thoughts on the child, expressed in the most fundamental and even popular form that Vygotsky himself used with his beginner-level students. As the title of Vygotsky's course indicates, these are foundations upon which cultural-historical researchers can rebuild the lost science of "pedology", a holistic approach to child development based on the dynamic unity of physical and mental development. Volume One includes translations of seven of Vygotsky's lectures that reflect his approach to pedology; the method of pedology and the "methodics" of the unit of analysis; the role of heredity and social environment in child development; and general laws of development in childhood that will help parents and teachers understand the way the child's endocrine system, nervous system, and mind change as the child enters a culture and learns to make history.