Galen and the ventricular system.

This paper examines the anatomy and physiology, together with the pathophysiology, of the ventricular system of the brain, as it was understood by arguably its greatest exponent in Western Antiquity, Galen. According to him, the purpose of the ventricles was to elaborate, store and distribute psychic pneuma, the motive force of Galenic neurology, throughout the nervous system. However, impressive as the delineation of the ventricular system is, the details of this distribution are not forthcoming from Galen. Finally, I discuss the ventricles as the site of intellect, a notion only tentatively advanced by Galen, but cast into dogma by his successors. For all the mistakes Galen made in anatomy and physiology, the study of the ventricular system reveals a mind not dissimilar to our own.