This is the first book-length scholarly study of the medical ethics of John Gregory (1724-1773), who wrote the first English-language bioethics. This book shows how Gregory invented professional medical ethics and, in the process, the concept of the profession of medicine as a fiduciary profession. Making extensive use of manuscript and other primary sources, the book provides the first complete intellectual biography of Gregory, placing his medical ethics in its eighteenth-century contexts of Scottish Enlightenment history and culture, Baconian science and philosophy of medicine, medical practice, the feminine and feminist philosophy of the Bluestocking Circle, and moral sense philosophy, particularly David Hume's concept of sympathy. A detailed examination of his texts on medical ethics is followed by a consideration of the implications of Gregory's medical ethics for contemporary bioethics, especially feminist bioethics. This book is intended for scholars, teachers, and students of bioethics, medical ethics, the history of medicine, and the history of medical ethics.