Laws of Freedom is Mary J. Gregor's rigorous and illuminating study of Immanuel Kant's ethical framework, focusing on how the categorical imperative is applied in his Metaphysik der Sitten (Metaphysics of Morals). In clear and precise prose, Gregor examines Kant's method for translating abstract moral principles into concrete laws governing human freedom. Her work bridges the gap between philosophical theory and practical application, showing how Kant's moral philosophy operates not just as a system of thought but as a guide to action. Gregor analyzes the structure of the Metaphysik der Sitten, exploring the distinction between the Rechtslehre (Doctrine of Right) and the Tugendlehre (Doctrine of Virtue), and elucidates how the categorical imperative underpins both legal and ethical duties. By tracing Kant's reasoning and clarifying his terminology, she makes accessible the dense and often challenging aspects of his moral system. The study also situates Kant's ideas within their historical and intellectual context, showing their relevance to enduring questions about law, morality, and personal autonomy. Scholarly yet readable, Laws of Freedom is an essential resource for students and scholars of Kant, moral philosophy, and the philosophy of law. It offers a deep understanding of how one of philosophy's most influential thinkers sought to reconcile freedom with moral obligation, and how that reconciliation continues to shape debates in ethics and political theory today.