Onora O'Neill, Baroness O'Neill of Bengarve, is a former Principal of Newnham College Cambridge, sits as a cross-bench peer in the House of Lords and is Emeritus Honorary Professor at the University of Cambridge. She has published widely on Kant's philosophy and her most recent publications include Constructing Authorities (Cambridge, 2016), and Justice Across Boundaries: Whose Obligations? (Cambridge, 2016).

Acknowledgements; Introduction; Note on the references to Kant's works; Part I. Why Practical Principles Matter: 1. Modern moral philosophy and the problem of relevant descriptions; 2. Two cultures fifty years on; 3. Scientific inquiry and normative reasoning; Part II. Abstract Principles and Practical Judgement: 4. Abstraction, idealisation and ideology; 5. Normativity and practical judgement; 6. Instituting principles: between duty and action; 7. Experts, practitioners and practical judgement; 8. Kant on indeterminacy, judgement and interpretation; Part III. Means, Ends and Demands: 9. Reason and the resolution of disputes; 10. Consequences for non-consequentialists; 11. Demandingness and rules; Part IV. 'Applied' Ethics and Practical Judgement: 12. Applied ethics: naturalism, normativity and public policy; 13. Practical principles and practical judgement in bioethics; 14. Enactable and enforceable: Kant's criteria for right and virtue; Index.