This book provides the first comprehensive, historically based, philosophical interpretations of two texts of Thomas Percival s professional ethics in medicine set in the context of his intellectual biography. Preceded by his privately published and circulated Medical Jurisprudence of 1794, Thomas Percival (1740-1804) published Medical Ethics in 1803, the first book thus titled in the global histories of medicine and medical ethics. From his days as a student at the Warrington Academy and the medical schools of the universities of Edinburgh and Leyden, Percival steeped himself in the scientific method of Francis Bacon (1561-1626). McCullough shows how Percival became a Baconian moral scientist committed to Baconian deism and Dissent. Percival also drew on and significantly expanded the work of his predecessor in professional ethics in medicine, John Gregory (1724-1773). The result is that Percival should be credited with co-inventing professionalism in medicine with Gregory.