This text examines the fifth-century medical treatise, "On the Sacred Disease", as a sophistic speech, and considers its position within the scientific tradition. The first part concerns conceptions of science, magic and medicine; and establishes the antiquity of medicine as a specialized skill. The latter part analyzes the treatise in light of sophistic oratory, and explores its reception of traditional beliefs. This analysis shows that traditional beliefs, competition and rhetoric, contributed to the intellectual tradition of science. Traditional views are shown to have influenced ideas concerning physiology, and disease aetiology and transmission. Competition, expressed in terms of sophistic debate, strengthened the author's arguments. "On the Sacred Disease" is important evidence for the influence on fifth-century medicine of both sophistic rhetoric and of older medical traditions.