On Ancient Medicine, On the Art, On Breaths, On the Nature of Human Beings and On the Sacred Disease are among the most well-known and sophisticated works of the Hippocratic Collection. The authors of these treatises were seeking to find means to express their arguments that built on authoritative models of their predecessors. By examining the range of expressive resources used in their expository prose, James Cross demonstrates how oral tradition and written techniques, such as sound patterning, sign-posting and antithetical formulae, were deployed to help the writers develop a case. The book demonstrates that there were various layers of meaning and manners of communicating ideas which can be found in Hippocratic expository prose, and offers fresh insights into the oral debating culture and experiments in persuasion which characterise the ancient Greek world of the late fifth-century BCE.