Book excerpt: 2012 Reprint of 1962 Edition. Exact facsimile of the original edition, not reproduced with Optical Recognition Software. Vygotsky's closely reasoned, highly readable analysis of the nature of verbal thought as based on word meaning marks a significant step forward in the growing effort to understand cognitive processes. Speech is, he argues, social in origins. Speech is learned from others and, at first used entirely for affective and social functions. Only with time does it come to have self-directive properties that eventually result in internalized verbal thought. A classic work.