But what did Copernicus really believe? Some argue that he anticipated the vast secularizing impact his ideas would have on history. Others contend that Copernicus was a man of his time and, on the whole, accepted its worldview. William T. Vollmann navigates this territory with the energetic prose and powerful intelligence for which he is known, providing a fresh and enlightening explication of Copernicus, his book, and his time, and the momentous clash between them.