Philip van der Ejik gives a talk for the Causing Health and Disease: Medical Powers in Classical and Late Antiquit conference, held at Corpus Christi College on 21st-22 September 2012.
Greek medicine was, from the very beginnings, preoccupied with causal explanation and with theoretical reflection on causation as such. One area where the quest for causes and the question of causal efficacy was particularly pressing was that of the dunameis of substances, i.e. the powers of foods, drinks, drugs and other therapeutic measures to bring about changes in the body of the organism to which they were administered. How can these powers be determined and identified? What is their ontological status, considering that they do not always work? How are efficacy and inefficacy explained? This paper will focus on three medical thinkers who have addressed these questions: the author of the Hippocratic work On Regimen (5th-4th century BCE); Diocles of Carystus (4th century BCE); and Galen of Pergamum (2nd century CE).