The early concept that the cerebral ventricles harbor the soul began to break down only in the Renaissance. Thanks to determined anatomical studies and physiological considerations regarding the role played by the cerebrospinal fluid, the function of the ventricles was reduced to merely being a receptacle for metabolic waste.
Schiller F. The Cerebral VentriclesFrom Soul to Sink. Arch Neurol. 1997;54(9):1158-1162. doi:10.1001/archneur.1997.00550210086018