In this first volume of a three-volume work, a search for the foundation of authentic medical practice is undertaken by Dr. Adams prompted by a forty-year career in clinical medicine. After an analysis of primitive cultures, seven ancient civilizations, and modern Western medicine, only the medicine of Classical Greece and the modern West has approached what can be called a "natural state of medical practice," defined as "effective medical care effectively delivered free from external forces." In each case this was accomplished within two or three centuries. The absence of medical progress in primitive societies and its failure to mature in the ancient civilizations of Mesopotamia, Egypt, India, China, and the Americas is shown to be the consequence of authoritarianism. In contrast, the medical progress of ancient Greece and especially the modern West, which owes nothing whatever to prior civilizations, is explained solely by collegial exchange, within a free citizenry, of information and scientific analysis by a network of autonomous medical practitioners motivated by self-interest. It is argued that clinical care approximating that of the early 20th C might have been achieved by the time of Christ had not Hippocratic medicine prematurely ceased to exist. Extinct in the Dark Ages, medical progress in the West began anew in the 18th C, again with no obligation to prior civilizations, not even to Hippocratic medicine or to the Renaissance, but again the consequence of collegial sharing of knowledge by autonomous medical practitioners, now made more efficient via medical journals. After analyzing the failure of ancient medical practices to mature, Dr. Adams proposes an Isagorial Theory of Human Progress that identifies the toxic role of authoritarianism on human freedom. He concludes with a warning that recent infringements of the Hippocratic Oath presage another dire authoritarian blight infecting the medical profession. William H. Adams, MD, FACP, DCMT(London), now retired after forty years of medical practice primarily at large municipal hospitals in New York City and Boston, began his inquiry into what constitutes a proper medical practice because of unsatisfactory features of modern medicine. As an internist with the subspecialty of hematology and with clinical credentials in tropical medicine, his efforts began with the translation of Hippocratic medical treatises most closely aligned with internal medicine. But, as he reviewed ancient medical practices around the world, sociopolitical patterns affecting medical practice emerged that extended the breadth of his studies, ultimately to include even prehistoric civilizations. The conclusions of twenty years of attention to his topic are detailed in three volumes entitled "The Natural State of Medical Practice," and, encompassing areas unintended at the beginning, reveal a new theory of human progress with implications far beyond medical practice.