Andrew Errington brings the Book of Proverbs into discussion with two significant accounts of the nature and foundation of practical reason in Christian ethics: those of Thomas Aquinas and Oliver O'Donovan. Aiming to move towards a framework for understanding Christian moral reasoning, this book develops a significant critique of aspects of Aquinas's thought and provides a major engagement with O'Donovan's moral theology. Errington argues that the way the Book of Proverbs conceives of wisdom presents an important challenge to the Western theological and philosophical tradition. Instead of a perfection of theoretical knowledge, wisdom in Proverbs is a practical knowledge of how to act well, grounded in the reality of the world God has made. Discussing the complexities of practical reason, moral reasoning in Aquinas, world order and deliberation in the work of O'Donovan, and the place of created order in Christian Ethics, this volume is invaluable for scholars and general readers in reconfiguring moral theology.