How does law possess the normative force it requires to direct our actions? This book argues that this seemingly innocuous question is of central importance to the philosophy of law and, by extension, of the very concept of law itself. It advances a position grounded in the secular natural law tradition, and in doing so addresses the two success criteria for this position head on: Firstly, that commitment to the existence of a supreme moral principle is required; Secondly, that any supreme moral principle must be identifiable through human reason. The book argues that these conditions are...