Ventricular localization in late antiquity: The philosophical and theological roots of an enduring model of brain function.

Ventricular localization, or cell theory, is first attested in Christian texts of the fourth and fifth centuries CE. It remained dominant in learned medicine until the seventeenth century. Contrary to common representation, the earliest theorists of ventricular localization were not trying to displace the faculties of the rational soul from the substance of the brain to the empty spaces and spirit within. Rather, they considered the substance and structure of the brain vital to the operations of the soul. Late antique accounts of ventricular localization envision the ventricles as "instruments" of the soul. These instruments are best imagined through the ancient figure of the lyre, as hollow structures that resonate with the passage of air and the movement of strings, or nerves.