Page:The Gradual Acceptance of the Copernican Theory of the Universe.djvu/37

 devoted pupil and friend, Rheticus, aided by Tiedeman Giese, Bishop of Culm and a lifelong friend, at length (1542) persuaded him. So he entrusted the matter to Giese who passed it on to Rheticus, then connected with the University at Wittenberg as professor of mathematics. Rheticus, securing leave of absence from Melancthon his superior, went to Nürnberg to supervise the printing. This was done by Petrejus. Upon his return to Wittenberg, Rheticus left in charge Johann Schöner, a famous mathematician and astronomer, and Andreas Osiander, a Lutheran preacher interested in astronomy. The printed book was placed in Copernicus's hands at Frauenburg on May 24th, 1543, as he lay dying of paralysis.

Copernicus passed away that day in ignorance that his life's work appeared before the world not as a truth but as an hypothesis; for there had been inserted an anonymous preface "ad lectorem de hypothesibus huius opera" stating this was but another hypothesis for the greater convenience of astronomers. "Neque enim necesse est eas hypotheses esse veras, imo ne verisimiles quidem, sed sufficit hoc unum, si calculum observationibus congruentem exhibeant." —For years Copernicus was thought to have written this preface to disarm criticism. Kepler sixty years later (1601) called attention to this error, and quoted Osiander's letters to Copernicus and to Rheticus of May, 1541, suggesting that the system be called an hypothesis to avert attacks by theologians and Aristotelians. He claimed that Osiander had written the preface; but Kepler's article never was

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