The notion of competence in A Philosophical Basis of Medcial Practice presents a problem concerning the ontology of the body. This paper will maintain that an ontology of the body can only be based upon Cartesian grounds whereby the scientific knowable order is supposed to be identical to the natural order of things. Moral questions are not a part of this order and depend upon free will. Foucault has demonstrated that such a dualism between nature and morality cannot be warranted for contemporary medical practice. Medical science does not derive its foundation from a natural order but from the order of knowing which is present in the body of knowledge (episteme). This body of knowledge is the significative cultural force in the way of looking at problems of disease, life and death. Thus in contemporary medical practice, concepts of morality and competence which are based on notions of free will, shall be discarded as non-sensical, even for the patient.