This edited volume examines the relationship between collective intentionality and inferential theories of meaning. The book consists of three main sections. The first part contains essays demonstrating how researchers working on inferentialism and collective intentionality can learn from one another. The essays in the second part examine the dimensions along which philosophical and empirical research on human reasoning and collective intentionality can benefit from more cross-pollination. The final part consists of essays that offer a closer examination of themes from inferentialism and collective intentionality that arise in the work of Wilfrid Sellars.  Groups, Norms and Practices provides a template for continuing an interdisciplinary program in philosophy and the sciences that aims to deepen our understanding of human rationality, language use, and sociality.