The exponential growth in the power and reach of artificial intelligence poses a special challenge for the rule of law: AI and machine learning have colonized the law itself. AI, suitably regulated, has a role to play in ordinary operations of the law, but it must not take the place of law. AI’s distinctive modus operandi, its characteristic mode of reasoning and its design for social control, contrasts sharply with law’s distinctive mode of reasoning. Governance by algorithm leaves no room for legal reasoning, and hence no room for judgment, reflection, interpersonal engagement, or personal decision-maker responsibility. But we might ask what of value would be lost to us as individuals and to our political communities if AI were to replace law in a large swath of our political and personal lives? This lecture explores and assesses several potential consequences of the replacement of law with AI technologies. The Institute for Ethics in AI will bring together world-leading philosophers and other experts in the humanities with the technical developers and users of AI in academia, business and government. The ethics and governance of AI is an exceptionally vibrant area of research at Oxford and the Institute is an opportunity to take a bold leap forward from this platform. Every day brings more examples of the ethical challenges posed by AI; from face recognition to voter profiling, brain machine interfaces to weaponised drones, and the ongoing discourse about how AI will impact employment on a global scale. This is urgent and important work that we intend to promote internationally as well as embedding in our own research and teaching here at Oxford.