Valentine's career is a typical example of the personally obscure but intellectually brilliant lives {56} which these old monks lived. It seems probable, according to the best authorities, as we have said, that his work began shortly before the middle of the fifteenth century, although most of what was important in it was accomplished during the second half. It would not be so surprising, as most people who have been brought up to consider the period just before the Reformation in Germany as wanting in progressive scholars might imagine, for a supremely great original investigator to have existed in North Germany about this time. After all, before the end of the century, Copernicus, the Pole, working in northern Germany, had announced his theory that the earth was not the center of the universe, and had set forth all that this announcement meant. To a bishop-friend who said to him, "But this means that you are giving us a new universe," he replied that the universe was already there, but his theory would lead men to recognize its existence. In southern Germany, Thomas à Kempis, who died in 1471, had traced for man the outlines of another universe, that of his own soul, from its mystically practical side. These great Germans were only the worthy contemporaries of many other German scholars scarcely less distinguished than these supreme geniuses. The second half of the fifteenth century, the beginning of the Renaissance in Germany as well as Italy, is that wonderful time in history when somehow men's eyes were opened to see farther and their minds broadened to gather in more of the truth of {57} man's relation to the universe, than had ever before been the case in all the centuries of human existence, or than has ever been possible even in these more modern centuries, though supposedly we are the heirs of all the ages in the foremost files of time.