It is hard to believe that Lev Semënovich Vygotsky's impressive contribution to Soviet psychology began in the same year and in the same city as the turgid controversy between the Mechanists and the Deborinites. From his debut on the Soviet psychological stage in 1924 until his death from tuberculosis only ten years later, Vygotsky produced a series of works that abound with creative insights. In contrast to his philosophical contemporaries, Vygotsky's career was marked by theoretical achievements that have had a direct and enduring influence. It is now common to talk of a “Vygotsky School” in Soviet psychology (sometimes known as the “sociohistorical” or “cultural-historical” school), which includes A. N. Leontiev and A. R. Luria, who both worked under Vygotsky in their youth, and a younger group of educational psychologists, of whom A. I. Meshcheryakov and V. V. Davydov are best known. In addition, Vygotsky has a growing following in the West, where Jerome Bruner, Michael Cole, James Wertsch, and others have suggested that his ideas speak to the quandaries and confusions that haunt Western psychology today. Now that a Russian edition of his collected works has at last appeared, Vygotsky's influence is set to grow still further.

Vygotsky's approach to psychology is remarkable both for its theoretical intensity and its sense of mission. Vygotsky believed that the psychology of his day bore the characteristics typical of any young science: It was composed of a fragmented hodgepodge of competing schools employing different, and often incompatible, methods.