What are our reasons for acting? Morality purports to give us these reasons, and so do norms of prudence and the laws of society. The theory of practical reason assesses the authority of these potentially competing claims, and for this reason philosophers with a wide range of interests have converged on the topic of reasons for action. This volume contains eleven new essays on practical reason by leading and emerging philosophers. Topics include the differences between practical and theoretical rationality, practical conditionals and the wide-scope ought, the explanation of action, the sources of reasons, and the relationship between morality and reasons for action. The volume will be essential reading for all philosophers interested in ethics and practical reason.