Xunzi’s 荀子 advocacy for moral education is well-documented; precisely how his program bolsters moral development, and why a program touting study of ritual could be effective, remain subjects of debate. I argue that these matters can be clarified by appealing to the theory of learning and development offered by Lev Vygotsky. Vygotsky posited that development depends primarily on social interactions mediated by sociocultural tools that modify learners’ cognitive architecture, enabling increasingly sophisticated thought. Vygotsky’s theory is remarkably similar to Xunzi’s account of how studying and practicing ritual restructures learners’ moral psychology. Specifically, both Vygotsky and Xunzi offer nonnativist accounts of psychosocial development that emphasize the centrality of sociocultural tools for learning. This comparison yields a more nuanced and empirically supported interpretation of Xunzi’s account of moral education, as well as an account that has applications in contemporary work in moral education and development.