Should social and political practices play a role in the justification of normative political principles? In several sub-domains of political theory, theorists have suggested that practices constrain principles in various ways. This book joins five key debates in the current theoretical literature that have been largely taking place in isolation and identifies common strands of argument and their shared problems. By illuminating these connections and cross-fertilising key debates in the current theoretical literature, it develops a unified way forward for practice-based political theory.