This book offers a comprehensive, modern understanding of legal philosophy through an evolutionary lens. Taking a highly interdisciplinary approach throughout, the book first explores the history of ‘classic evolutionism&, regarding theories of law and justice from the authors of the Scottish Enlightenment to Hayek. The second part of the book analyses the contributions of new schools of thought, including evolutionary psychology, evolutionary game theory and co-evolutionist theories. The final part of the book builds a fresh argument for a modern evolutionary account of law, considering key methodological debates and the evolution at its three levels & biological, social and individual & to explain the emergence, stabilization and change of legal rules. This book is a timely addition to the growing interest in evolutionary thinking across the sciences, and will be of interest to a wide range of scholars including historians and philosophers of law as those interested in the intersection of law and psychology, law and economics, and the classical liberal tradition.