Herophilus and Erasistratus on Dissection

This study examines the epistemological foundations of early Hellenistic medicine through the surviving fragments and testimonies of Herophilus of Chalcedon and Erasistratus of Ceos, the first physicians in antiquity to practise systematic human dissection. While modern scholarship has often attributed the emergence of dissection in third-century BCE Alexandria to a multifarious horizon of explanations pointing to exceptional social, political, or cultural circumstances, this dissertation shifts the focus to the internal motivations that shaped these doctors’ methodological choices. The main question I address is: Which assumptions led to the integration of dissection into the medical practice of Herophilus and Erasistratus? I argue that their adoption of dissection was rooted in deeper epistemological commitments, in particular with regard to the authority of perception, the scope of medical enquiry and the relationship between observation and theory. This study uses a close reading of the surviving fragmentary evidence to show how Herophilus and Erasistratus conceptualised anatomical investigation and justified the use of dissection as a means of acquiring knowledge. In doing so, I show that Aristotle’s conceptual framework offered an anchoring ground for Herophilus and Erasistratus, especially with regard to the relationship between medicine and natural philosophy, the distinction between science and art, and the epistemological role of dissection in the study of living bodies. In the case of Herophilus, the close reading of the saying “Let the phenomena be called primary, even if they are not primary” supports the conclusion that phenomena revealed through dissection are epistemically primary for medical inquiry. The examination of Erasistratus’ fragments and testimonies shows that dissection supplied anatomical data for physiological investigation and that the concept of “what is observable by reason” (logōi theōrēton) was used to address what lies beyond perception while remaining closely constrained by observable phenomena, without further ontological commitments. This dissertation adds to the ongoing discussion about the role of dissection in ancient medicine, highlighting the interplay between methodological reflection and medical practice. Rather than portraying human dissection as an extraordinary event, this work contextualises it within a broader epistemological shift that redefined how knowledge of the body could be acquired, justified and challenged in Hellenistic medicine.