Psychiatry is the study of mental illnesses and their treatment. Its starting point and foundation is the scientific understanding of the nature of mental disorders. In addressing this task, the physicians of antiquity had already advanced to the point where they associated madness with certain physical disturbances, particularly with fever and changes in bodily fluids. Unfortunately, these views, which had developed into established doctrines, were almost completely lost with the collapse of the ancient culture. Instead, during the Middle Ages, scholastic-philosophical and religious-superstitious ideas infiltrated the understanding of madness and quickly displaced the existing nascent concepts of a scientific understanding. Mental disorder was no longer seen as an illness, but rather as a work of the devil.