Since it was introduced to the English-speaking world in 1962, Lev Vygotsky's Thought and Language has become recognized as a classic foundational work of cognitive science. Its 1962 English translation must certainly be considered one of the most important and influential books ever published by the MIT Press. In this highly original exploration of human mental development, Vygotsky analyzes the relationship between words and consciousness, arguing that speech is social in its origins and that only as children develop does it become internalized verbal thought. In 1986, the MIT Press published a new edition of the original translation by Eugenia Hanfmann and Gertrude Vakar, edited by Vygotsky scholar Alex Kozulin, that restored the work's complete text and added materials to help readers better understand Vygotsky's thought. Kozulin also contributed an introductory essay that offered new insight into Vygotsky's life, intellectual milieu, and research methods. This expanded edition offers Vygotsky's text, Kozulin's essay, a subject index, and a new foreword by Kozulin that maps the ever-growing influence of Vygotsky's ideas.

Lev Vygotsky (1896-1934) studied at Moscow University. He began his systematic work in psychology at the age of 28, and within a few years formulated his theory of the development of specifically human higher mental functions. He died of tuberculosis in 1934. Thought and Language was published posthumously that same year. Alex Kozulin began his investigation of Vygotsky's theory at the Moscow Institute of Psychology and continued it in Boston and then Jerusalem. He is the author of Psychology in Utopia: Toward a Social History of Soviet Psychology (MIT Press, 1984) and Vygotsky's Psychology: A Biography of Ideas and is a coeditor of Vygotsky's Educational Theory in Cultural Context.