ten years altogether, studying civil law at Bologna, and canon law and medicine at Padua, yet receiving his degree as doctor of canon law from the university of Ferrara in 1503. He was also in Rome for several months during the Jubilee year, 1500.
At this period the professor of astronomy at Bologna was the famous teacher Dominicus Maria di Novara (1454-1504), a man "ingenio et animo liber" who dared to attack the immutability of the Ptolemaic system, since his own observations, especially of the Pole Star, differed by a degree and more from the traditional ones. He dared to criticise the long accepted system and to emphasize the Pythagorean notion of the underlying harmony and simplicity in nature; and from him Copernicus may have acquired these ideas, for whether they lived together or not in Bologna, they were closely associated. It was here, too, that Copernicus began his study of Greek which later was to be the means of encouraging him in his own theorizing by acquainting him with the ancients who had thought along similar lines.
In the spring of the year (1501) following his visit to Rome, Copernicus returned to the Chapter at Frauenburg to get further leave of absence to study medicine at the University of Padua. Whether he received a degree at Padua or not and how long he stayed there are uncertain points. He was back in Ermeland early in 1506.
His student days were ended. And now for many years he led a very active life, first as companion and assistant to his uncle the Bishop, with whom he stayed at Schloss Heilsberg till after the Bishop's death in 1512; then as one of the leading canons of the chapter at Frauenburg, where he lived most of the rest of his life. As the chapter representative for five years (at intervals) he had oversight of the spiritual and temporal affairs of two large districts in the care of the chapter. He went on various diplomatic and other missions to the King of Poland, to Duke Albrecht of the Teutonic Order, and to the councils of the German states. He wrote a paper of considerable weight upon the much needed reform of the Prussian currency. His skill as a physician was in demand not only in his immediate circle but in adjoining countries, Duke Albrecht once summoning him to Königsberg to attend one of his courtiers. He was a humanist as well as a Catholic Churchman, and though he did not approve of the Protestant Revolt, he favored reform and toleration. Gassendi claims that he was also a painter, at least in his student days, and that he painted portraits well received by his contemporaries. But his interest and skill in astronomy must have been recognized early in his life for in 1514 the committee of the Lateran Council in charge of the reform of the calendar summoned him to their aid.
He was no cloistered monk devoting all his time to the study of the heavens, but a cultivated man of affairs, of recognized ability in business and statesmanship, and a leader among his fellow canons. His mathematical and astronomical pursuits were the occupations of his somewhat rare leisure moments, except perhaps during the six years with his uncle in the comparative freedom of the bishop's castle, and during the last ten or twelve years of his life, after his request for a coadjutor had resulted in lightening his duties. In his masterwork De Revolutionibus there are recorded only 27 of his own astronomical observations, and these extend over the years from 1497 to 1529. The first was made at Bologna, the second at Rome in 1500, and seven of the others at Frauenburg, where the rest were also probably made. It is believed the greater part of the De Revolutionibus was written at Heilsburg where Copernicus was free from his chapter duties, for as he himself says