Vita brevis, ars longa. This is the Latin translation of the first two lines of an aphorism by Hippocrates which reads: O βιoς βραχυς, η δε τεχνη μακρη (Aphorims, section I, No. 1). It shows that in Ancient Greece medicine was viewed as an art, téchne. The view persisted in Western medicine until medical research joined the methodology of natural sciences in the late eighteenth century. The judgment soon emerged that medicine had been an unscientific endeavor in the past and had now become a scientific discipline: "Medicine will be a science, or it will not be" (Naunyn , 1909, 1348). The terms 'science" and 'scientific" were overtly identified with natural science. Any deviant approach was considered unscientific, e.g., humoral pathology and homeopathy, and had to be banished from medicine. Since then there is, between the proponents and opponents of this view, an ongoing debate on the " nature of medicine" concerned with whether medicine is a science or an art. We will not participate in this long-standing controversy because the very question is pointless for different reasons. For a detailed discussion on this issue, see Chapter 21 and (Marcum , 2008, 301 ff.).