Forthcoming in Kazantzidis, G. & Gerolemou M., Body and Machine in Classical Antiquity, Cambridge University Press. 1 The Mechanics of Galen’s Theory of Nutrition 1 Orly Lewis Abstract This chapter explores Galen’s ideas concerning the digestive-nutritive process. It focuses on his explanation of the motion of nutritive matter from its ingestion as food through its alteration into blood and until its complete assimilation to the different body parts. The discussion follows its path inside the body from the mouth to the individual parts and describes the changes it undergoes in its different anatomical ‘stations’ and by what means it moves through these ‘stations’. In so doing it brings to light a fundamental but generally overlooked part of the digestive-nutritive process in Galen, namely physical motions of the parts such as the oesophagus, stomach and intestines. The chapter shows how these motions of contraction and extension actively and ‘mechanically’ move the nutritive matter into and through the body by pulling, pushing and compressing the parts of the body and the matter they hold inside them. A Note on the Illustrations This chapter includes seven illustrations which are intended to assist readers in following the anatomical details depicted in this chapter and thus in understanding the discussion of Galen’s theory. The illustrations are the product of the collaborative work between: the author; the illustrator – Yotam Giladi; and experts in anatomy – Joshua Milgram and Esteban Marroquín Arroyave of the Koret School of Veterinary Medicine at The Hebrew University of Jerusalem (HUJI). All are members of the research group ATLOMY (Anatomy in Ancient Greece and Rome: An Interactive Visual and Textual Atlas – see n. 1). It is not possible to discuss here in detail the considerations and sources informing each illustration, but I highlight a few points: 1. The illustrations are based on close readings of key passages in Galen. They are visualisations of the body parts as described by Galen in terms of their general shape, location, connections and mutual proportions. They are not intended as an exhaustive depiction of his anatomical understanding of these body parts. They depict the features discussed in the chapter and additional key properties required for understanding the discussion. 1 This research has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (GA 852550 – project ATLOMY). Earlier stages of the research were funded by the Martin Buber Society of Fellows for the Humanities and Social Sciences at The Hebrew University of Jerusalem. I am grateful to the editors for their patience and comments as well as for their warm hospitality during the conference from which this volume stems. Thank you also to Giouli Korobili, Julius Rocca, Peter Singer and Chiara Thumiger for their helpful comments and to Dimitry Ezrohi, Premshay Hermon and Nir Propper for their assistance. A special thanks also to Esteban Marroquín Arroyave, Joshua Milgram and Yotam Gildai for their assistance in interpreting Galen’s anatomical descriptions and their work in producing the illustrations; and to Assaf Marom at the Anatomy and Human Evolution Lab and the instructors at the Anatomy Research and Education Centre, both at the Israel Institute of Technology, for their advice and practical instruction on the anatomy of the digestive system in humans.