According to the natural law account of practical rationality, the basic reasons for actions are basic goods that are grounded in the nature of human beings. Practical rationality aims to identify and characterize reasons for action and to explain how choice between actions worth performing can be appropriately governed by rational standards. Natural Law and Practical Rationality is a defense of a contemporary natural law theory of practical rationality, demonstrating its inherent plausibility and engaging systematically with rival egoist, consequentialist, Kantian and virtue accounts.