Nemesius of Emesa was a Christian philosopher, and the author of a treatise De natura hominis (“On Human Nature”). According to the title of his book, he was the Bishop of Emesa (in present-day Syria). His book is an attempt to compile a system of anthropology from the standpoint of Christian philosophy; it was very influential in later Greek, Arabic and Christian thought.
Nemesius was also a physiological theorist. He based much of his writing on previous work of Aristotle and Galen, and it has been speculated that he anticipated William Harvey’s discovery of the circulation of blood. Other views included a five-theory hierarchy of divine providence. These theories are developed from an earlier Platonic theory.
Nemesius was one in a succession of advocates, from Herophilus and Erasistratus onward, of the idea that different cavities of the brain were responsible for different functions. His Doctrine of Ventricle Localisation of Mental Functioning is a reconciliation of Platonic doctrines on the soul with Christian philosophy and also emphasized Greek scientific interpretation and knowledge of the human body.