The Absent Immune System: Exploring Perceptions of Disease and Contagion in Ancient Greek Medical Theory

Almost every medical achievement of the modern day has its origins in the advancements made by the Greek medical theorists of Antiquity. Although unaided by modern instruments or techniques, Greek medical theorists developed a plausible theory for nearly every aspect of human physiology, with one glaring exception: contagion. Among the many surviving medical treatises from Greek authors, not one explicitly describes, explains, or predicts any aspect of contagion or the body’s response to it. The purpose of this thesis is to gain a better understanding of how such a key component of medical theory was overlooked. Using both medical and non-medical sources from antiquity, this thesis proposes that the absence of contagion in Greek medical theory was driven by a range of social and geographical factors which, in various historical contexts, ultimately discouraged physicians from developing a working theory of infectious disease.