The Hippocratic Oath, the Hippocratic tradition, and Hippocratic ethics are widely invoked in the popular medical culture as conveying a direction to medical practice and the medical profession. This study critically addresses these invocations of Hippocratic guideposts, noting that reliance on the Hippocratic ethos and the Oath requires establishing (1) what the Oath meant to its author, its original community of reception, and generally for ancient medicine (2) what relationships contemporary invocations of the Oath and the tradition have to the original meaning of the Oath and its original reception (3) what continuity exists and under what circumstances over the last two-and-a-half millenniums of medical-moral reflections (4) what continuity there is in the meaning of professionalism from the time of Hippocrates to the 21st century, and (5) what social factors in particular have transformed the medical profession in particular countries. This article argues that the resources for a better understanding of medical professionalism lie not in the Hippocratic Oath, tradition, or ethos in and of themselves. Rather, it must be found in a philosophy of medicine that explores the values internal to medicine, thus providing a medical-moral philosophy so as to be able to resist the deformation of medical professionalism by bioethics, biopolitics, and governmental regulation. The Oath, as well as Stephen H. Miles' recent monograph, The Hippocratic Oath and the Ethics of Medicine, are employed as heuristics, so as to throw into better light the extent to which the Hippocratic Oath, tradition, and ethics can provide guidance and direction, as well as to show the necessity of taking seriously the need for a substantive philosophy of medicine.