Vygotsky's voluminous correspondence well known for its international extent has been lost during the turmoil of war. Partly by accident partly after hard investigation some of his letters to friends, disciples, and colleague scholars have been recovered. Their contents are of high interest to issues regarding both his biography and the history of his work. Importantly, they provide new insights into his personal relations, especially to Leontiev. The present book is the first comprehensive compilation of Vygotsky's letters which are available at the moment. It additionally includes the accessible replies of his addressees.