“Mechanics” and Mechanism in William Harvey’s Anatomy: Varieties and Limits

Peter Distelzweig

Western Michigan University

Abstract: 
William Harvey’s De motu cordis (1628) is an important text in the history of medicine and played a prominent role in the rise of mechanical and experimental approaches to natural philosophy in the 17th century. Descartes, Hobbes and Boyle (among others) praised Harvey’s short, cogent argument for the forceful systole of the heart and the circulation of the blood. Hobbes even suggested that Harvey was to the science of the human body what Galileo was to the science of motion and Copernicus to astronomy. It is perhaps surprising, then, that Harvey’s was a self-consciously Aristotelian and Galenic approach to anatomy. He understood the goal of anatomy to be final causal Aristotelian scientia of the parts of animals articulated using the Galenic notions of the ‘actions’ and ‘uses’ of the parts. Furthermore, Harvey defended the existence of a non-mechanical ‘pulsific virtue’ in the heart and was critical of Descartes’ mechanistic account of its motions and, more generally, of the corpuscularianism associated with (e.g.) Descartes, Gassendi, Hobbes and Boyle. Indeed, in his work on generation he criticizes his teacher Hieronymus Fabricius ab Aquapendente for being overly influenced by the thinking of mechanics. At the same time, in the De motu cordis he compares the passive expansion of the arteries to the inflation of a glove and the expansion of a bladder, and in the Letters to Riolan he compares the heart to a pump. Furthermore, in his early lecture notes, Harvey compares various digestive organs to chemical apparatuses, and in his working notes on animal locomotion and its organs, he sketches a program for integrating mathematical mechanics into the study of muscle anatomy and considers a multi-step process leading to muscle contraction under the heading of ratio mechanica. Clearly, Harvey’s attitude towards ‘mechanics’ and ‘mechanical’ is a complex one. This should be no surprise, as the nature and meaning of ‘mechanics’ and ‘mechanical’ in the early 17th century is itself a complex and multi-faceted issue. In this paper I explore the complex and varied uses of mechanics/the mechanical in Harvey’s works. I show that Harvey has a consistent, coherent understanding of the place of mechanism and mechanics in his, nonetheless, Galeno-Aristotelian approach to anatomy.