"With the advent of Humanist Renaissance in the fifteenth century astrology enjoyed a major revival centred around astro-medicine, or as it was also known iatro-mathematics, a discipline that like astrology had its roots in fourth century BCE Greece. This form of medicine believed that the causes and cures of diseases were controlled by celestial influences and that a medicus must study the horoscopes of both the patient and the disease to determine the correct course of treatment. Chairs of astrology were established at the Northern Italian humanist universities and also in Cracow in Poland, later in other parts of Europe. By the end of the century astrology was the central discipline studied and practiced by the Renaissance mathematicus. This revival in the fortunes of astrology was also made possible because the new astrologers interpreted horoscopes as being indicative and no longer deterministic. That is a horoscope indicated a possible course for the future but one that could be altered by the subject of the horoscope if he took the right actions. Actions defined by the astrologer, of course, for a further fee."