"Vygotsky’s Neglected Legacy": Cultural-Historical Activity Theory Wolff-Michael Roth and Yew-Jin Lee present cultural-historical activity theory (CHAT), a theoretical framework that has been largely overlooked in academia. Originally proposed by Lev Vygotsky, CHAT was significantly developed by his students and followers, leading to its second and third generations. This theory offers a holistic approach to understanding language, language learning, and literacy, and is a theory for praxis that can help overcome challenges in educational theory and practice. Vygotsky criticized traditional psychology for its focus on isolated mental processes, arguing that they were disconnected from the fullness of life. His student, A. N. Leont'ev, continued to critique the state of educational psychology. Despite this, research in education has not fully embraced Vygotsky's holistic integration of learning and life. Katherine, a fifth-grade teacher, faces contradictions between her personal experience and professional goals, struggling to balance direct teaching with hands-on learning. She lacks the theoretical tools to understand how learning is a by-product of pursuing motives and goals, and how language mediates the realization of these goals. CHAT addresses these issues by providing a holistic theory of practical activity, which is essential for understanding education as a historically situated community. It helps educators understand the interplay between individual and collective, material and mental, biography and history, and praxis and theory. CHAT is particularly useful for analyzing data from real classrooms and designing change when contradictions arise. CHAT is rooted in dialectical materialism, classical German philosophy, and Vygotsky's first-generation activity theory. It was developed by Leont'ev and others to incorporate societal, cultural, and historical dimensions into the analysis of human mental functioning. CHAT has gained increasing interest in the Anglo-Saxon literature, as evidenced by citation data. CHAT is an integrative framework that offers a dialectical unit of analysis, allowing for an embodied mind and a transactive perspective. It emphasizes the mediation of activities by society and links concerns normally examined separately by sociologists of education and social psychologists. CHAT is particularly useful for understanding how learning is a by-product of the pursuit of motives and goals, and how language mediates the realization of these goals. CHAT has been used to reformulate educational issues, especially in the areas of language, language learning, and literacy. It offers new and fruitful avenues for learning theory and educational praxis. The authors argue that CHAT is deserving of wider currency in the educational community, as it provides a holistic understanding of learning and development. CHAT is a powerful tool for analyzing activity systems, using the "activity triangle" to reveal the social and material resources that are salient in activity. It emphasizes the interplay between individual and collective, material and mental, and the importance of mediation in learning. CHAT also highlights the importance of networks of activity systems, which are part of a larger network of activity systems that"Vygotsky’s Neglected Legacy": Cultural-Historical Activity Theory Wolff-Michael Roth and Yew-Jin Lee present cultural-historical activity theory (CHAT), a theoretical framework that has been largely overlooked in academia. Originally proposed by Lev Vygotsky, CHAT was significantly developed by his students and followers, leading to its second and third generations. This theory offers a holistic approach to understanding language, language learning, and literacy, and is a theory for praxis that can help overcome challenges in educational theory and practice. Vygotsky criticized traditional psychology for its focus on isolated mental processes, arguing that they were disconnected from the fullness of life. His student, A. N. Leont'ev, continued to critique the state of educational psychology. Despite this, research in education has not fully embraced Vygotsky's holistic integration of learning and life. Katherine, a fifth-grade teacher, faces contradictions between her personal experience and professional goals, struggling to balance direct teaching with hands-on learning. She lacks the theoretical tools to understand how learning is a by-product of pursuing motives and goals, and how language mediates the realization of these goals. CHAT addresses these issues by providing a holistic theory of practical activity, which is essential for understanding education as a historically situated community. It helps educators understand the interplay between individual and collective, material and mental, biography and history, and praxis and theory. CHAT is particularly useful for analyzing data from real classrooms and designing change when contradictions arise. CHAT is rooted in dialectical materialism, classical German philosophy, and Vygotsky's first-generation activity theory. It was developed by Leont'ev and others to incorporate societal, cultural, and historical dimensions into the analysis of human mental functioning. CHAT has gained increasing interest in the Anglo-Saxon literature, as evidenced by citation data. CHAT is an integrative framework that offers a dialectical unit of analysis, allowing for an embodied mind and a transactive perspective. It emphasizes the mediation of activities by society and links concerns normally examined separately by sociologists of education and social psychologists. CHAT is particularly useful for understanding how learning is a by-product of the pursuit of motives and goals, and how language mediates the realization of these goals. CHAT has been used to reformulate educational issues, especially in the areas of language, language learning, and literacy. It offers new and fruitful avenues for learning theory and educational praxis. The authors argue that CHAT is deserving of wider currency in the educational community, as it provides a holistic understanding of learning and development. CHAT is a powerful tool for analyzing activity systems, using the "activity triangle" to reveal the social and material resources that are salient in activity. It emphasizes the interplay between individual and collective, material and mental, and the importance of mediation in learning. CHAT also highlights the importance of networks of activity systems, which are part of a larger network of activity systems that