Historical aspects of Galen's neural transmission theories

Julius Rocca
Wellcome Research Fellow, Cambridge and Research Affiliate, Office for History of Science, University of Uppsala

Contrary to expectation, Galen held several theories regarding neural transmission, all admittedly making use of pneuma to some degree. Galen believed that his experiments showed that the body is deprived of sensation and motion when the ventricles of the brain are opened, and the pneuma escapes; this being so, pneuma is useful therefore for sensation and motion. From this, Galen adds no less than six possible theories of "neural transmission". This paper will seek to enumerate these theories, using as a paradigm Galen's treatment of the question of vision. Finally, some light will be cast on the history of subsequent neural transmission theories, noting that Galen's legacy is more complex than some later theorists assumed, for while Galen could almost be said to be sceptical in regard to which of his theories was correct, many of his interpreters held that Galen maintained a "doctrine" of animal or nervous spirits, interpreted either as pure pneuma or as some form of liquid within the alleged hollows of the nerves. This legacy of Galenism needlessly distorts some interesting theories Galen adumbrated concerning the nature of neural transmission.

Session I
Friday, 20 June 1997, 8.10 - 8.30

Second Annual Meeting of the International Society for the History of the Neurosciences (ISHN) and 6th Meeting of the European Club on the History of Neurology (ECHN)

Leiden, The Netherlands