The great performance of Copernicus (Nicolaus Koppernigk, 1473-1543), given to the world with an editor's treacherous preface as he lay paralysed on his deathbed, did not become a general possession for over a hundred years. The long reluctance of its author to let it be published, despite the express invitation of a cardinal in the name of the pope, was well founded in his knowledge of the strength of common prejudice; and perhaps partly in a sense of the scientific imperfection of his own case. [183] Only the special favour accorded to his first sketch at Rome--a favour which he had further carefully planned for in his dedicatory epistle to Pope Paul--saved his main treatise from prohibition till long after its work was done. [184] It was in fact, with all its burden of traditional error, the most momentous challenge that had yet been offered in the modern world to established beliefs, alike theological and lay, for it seemed to flout "common sense" as completely as it did the cosmogony of the sacred books. It was probably from scraps of ancient lore current in Italy in his years of youthful study there that he first derived his idea; and in Italy none had dared publicly to propound the geocentric theory. Its gradual victory, therefore, is the first great modern instance of a triumph of reason over spontaneous and instilled prejudice; and Galileo's account of his reception of it should be a classic document in the history of rationalism. It was when he was a student in his teens that there came to Pisa one Christianus Urstitius of Rostock, a follower of Copernicus, to lecture on the new doctrine. The young Galileo, being satisfied that "that opinion could be no other than a solemn madness," did not attend; and those of his acquaintance who did made a jest of the matter, all save one, "very intelligent and wary," who told him that "the business was not altogether to be laughed at." Thenceforth he began to inquire of Copernicans, with the result inevitable to such a mind as his. "Of as many as I examined I found not so much as one who told me not that he had been a long time of the contrary opinion, but to have changed it for this, as convinced by the strength of the reasons proving the same; and afterwards questioning them one by one, to see whether they were well possessed of the reasons of the other side, I found them all to be very ready and perfect in them, so that I could not truly say that they took this opinion out of ignorance, vanity, or to show the acuteness of their wits." On the other hand, the opposing Aristoteleans and Ptolemeans had seldom even superficially studied the Copernican system, and had in no case been converted from it. "Whereupon, considering that there was no man who followed the opinion of Copernicus that had not been first on the contrary side, and that was not very well acquainted with the reasons of Aristotle and Ptolemy, while, on the contrary, there was not one of the followers