Galen’s understanding of the digestive system in the context of the commensurability of medical knowledge in different periods

Abstract

The foundations of ancient rational medicine were laid by Hippocrates, but the credit for rethinking medicine as a comprehensive system of protoscientific knowledge belongs to Galen. Before him, medicine had no unified system of thought on the basic principles of the structure of living things, and no systemic approach to clinical practice, based on the apodictic method. In this article, I examine Galen’s teachings on the digestive system (one of the key aspects of his system) in terms of the “commensurability” of the ideas of ancient medicine and modern science. An analysis of the information in Galen’s works indicates that his system of theory and practice is substantially commensurable with the principles of modern medicine: many aspects of modern theory and practice represent a development of Galen’s ideas. A comparative analysis of Galen’s reconstructed views and those found in modern medicine calls for the use of tools from philosophy and the history of science to enable a correct interpretation of the historical medical texts. Such fundamental concepts include “type of rationality” and “scientific worldview”. This research is based on extant texts by Galen, primarily his two treatises On the Natural Faculties and On the Usefulness of the Parts of the Body, which may be regarded as fundamental to reconstructing Galen’s views on physiology and anatomy. Galen constructs a comprehensive system rather than simply listing individual facts he knows. The treatises in question underline the comprehensive and systemic nature of the great Roman physician’s arguments, which were to a large extent supported by experiment.