Historical, Theoretical and Methodological Foundations of CHAT: Critical Deliberations

The paper critically analyses cultural-historical activity theory (CHAT) in two most important aspects - the basic unit of analysis (i.e., in essence, the subject of the theory) and the main epistemological and methodological principles. It is shown with several examples that the concepts and principles that CHAT took from Vygotsky's theory are absent in Vygotsky's theory and are ascribed to him by misunderstanding and misinterpretation. One may agree or disagree that cultural-historical theory and activity theory are different theories, despite their historical connections, but Leontiev's theory has no activity (and the concept of activity! ) as a unit of analysis, because the principle of the unity of consciousness and activity theory represents a completely different logic of analysis, which does not need units of analysis at all.