Astrology and astronomy were not then divorced. It was astrology that gave us astronomy. The angel that watched over a star looked after all persons who were born under that star's influence, or else appointed some other angel for the purpose. Every person had a guardian angel to protect him from the evil spirits that occasionally broke out of Hell and came up to earth to tempt men. Mathematics knows nothing of angels--it only knows what it can prove. Copernicus believed that, if certain stars did move, they moved by some unalterable law of their own. In riding on a boat he observed that the shores seemed to be moving past, and he concluded that a part, at least, of the seeming movements of planets might possibly be caused by the moving of the earth. In talking with astrologers he perceived that very seldom did they know anything of mathematics. And this ignorance on their part caused him to doubt them entirely. His faith was in mathematics--the thing that could be proved--and he came to the conclusion that astronomy and mathematics were one thing, and astrology and child-stories another. He remained at Bologna just long enough to turn the astrologers out of the society of astronomers. Novarra's lectures on astronomy were given in Latin, and in truth all learning was locked up in this tongue. But astrology and the theological fairy-tales of the people floated free. They were a part of the vagrant hagiology of the roadside preachers, who with lurid imaginations said the things they thought would help carry conviction home and make "believers." From Bologna Copernicus then moved on to Padua, where he remained two years, teaching and giving lectures. Here he devoted considerable time to chemistry, and on leaving he was honored by being given a degree by the University. Next we find him at Rome, a professor in mathematics and also giving lectures on chemistry. His lectures were not for the populace--they were for the learned few. But they attracted the attention of the best, and were commented upon and quoted by the various other teachers, preachers and lecturers. A daring thinker who expresses himself without reservation states the things that various others know and would like to state if they dared. It is often very convenient when you want a thing said to enclose the matter in quotation-marks. It relieves one from the responsibility of standing sponsor for it, if the hypothesis does not prove popular. Copernicus was only nineteen years old when Columbus discovered America, but it seems he did not hear of Columbus until he reached Bologna in Fourteen Hundred Ninety-five. At Rome he made various references to Columbus in his lectures; dwelt upon the truth that the earth was a globe; mentioned the obvious fact that in sailing westward Columbus did not sail his ship over the edge of the earth into Hell, as had been prophesied he would.