It's worth noting that at that time ‘medicine' as we understand the term today was viewed differently in the 15th century. In fact, there were two terms designated to define healing practices. The term ‘medicine' derived from the Latin verb medico, meaning "to drug". The practice of medicine therefore emphasized an ability to administer curative remedies. Such remedies might be the potions of quacks (quackery), developed only to make the seller a profit, or therapies that were invented or revised on the basis of experiences of a particular practitioner with patients and remedies. What was crucial to good medical practice was what we call nowadays "clinical experience": an experienced judgment about what remedies would help a particular patient. A medical education in universities, therefore, might supplement, but was not always necessary for "medical" practice. Hence, practitioners of medicine without university degrees were called "empirics" by the educated physicians. For their part, physicians themselves practiced another kind of healing art, "physic". The term derived from the Greek noun physis, meaning "nature". Physicians had to study natural philosophy because the purposes of physic were to preserve health and prolong life; healing the sick was an important part, but only one of the many parts, of physic. The physician had to be able to offer advice to the healthy as well as to the sick about how to live according to nature, for being in harmony with nature would result in the preservation of health as well as the prolongation of life. Thus "medicine" and "physic," as used in the late 15th century, are terms that suggest the differences between major traditions in the healing arts: one based upon experience, the other upon learning; one concerned primarily with healing, the other primarily with the preservation of health. Drohobych's appointment to King Casimir's court is an indication that he succeeded in both healing fields, because such an important position required extraordinary knowledge of philosophy and natural philosophy as well as practical experience in curing illnesses.