The vibrating nerve impulse in Newton, Willis and Gassendi: first steps in a mechanical theory of communication

In later editions of his two major works, Isaac Newton proposed an electrical hypothesis of nervous transmission. According to this hypothesis, an electrical aether permeates the nerve and transmits vibrations along it. This implies that the nerve is a communication line, and potentially, an extension of the mind. The opposite view was held by Cartesian mechanists, who taught that the nerve is a power line, transmitting either pressure or tension, and that the mind is separate from the nervous system. The Newtonian model eventually supplanted the Cartesian model in the mid 18th century, and became a crucial part of the conceptual environment in which neuroscience originated. In this paper I examine the scientific origins of the Newtonian model of nervous transmission. I argue that Newton's model relies on prior work by Thomas Willis and Pierre Gassendi. Willis supplied the anatomical and physiological "hard data" upon which the model was built. But Gassendi, a generation before, laid out the conceptual foundations of the problem, including the principle of impulse-transmission, and the corrolary principle of the muscle as an autonomous generator of force. I conclude that Gassendi's work has been undeservedly neglected as a turning-point in the history of neuroscience.