One of the most important Galenic texts dealing with the localisation and functionality of the parts of the soul is his Quod animi mores corporis temperamenta sequantur (QAM). The purpose of this project was to make available this crucial text at the borderline of medicine and philosophy in a critical edition with a detailed commentary. To this end the Greek manuscript traditon has to be meticulously compared with an early medieval Latin translation and an early Arabic translation.