With all his hardihood and self-confidence, Servetus was not without so much prudence as assured him that a certain amount of caution and reticence was required of everyone who would live at peace among his fellow men. He doubtless imagined at one time, but had already discovered his mistake, that among heretics, as he had been accustomed to hear the Reformers designated, he might freely expend himself in heresy. To the very end of his life, he seems to have had some difficulty in divining why he had not been welcomed by them with open arms as a brother. But he was well aware that Roman Catholic France had yet less in common with Michael Serveto, alias Revés, author of the Seven books and Two dialogues on Trinitarian Error, than Protestant Switzerland and Germany.
Servetus felt that the writer of these works could not safely show himself in Paris under either his proper family or his maternal name, and so fell readily upon one derived from the town of his nativity, Villanueva. Servetus seems indeed at no time to have been very particular as to his name and designation. On his trial at Vienne he is of Tudela in Navarre, on that at Geneva, of Villanova in Aragon; and Tollin finds him inscribed in the academic register of Paris (1536) and in that of Montpellier, which he must have visited some time in 1540, as neither of Tudela nor Villanova, but of Saragossa! During all the years he lived in France, he was never known save as Monsieur Michel Villeneuve, or, when he wrote in Latin, as Michael Villanovanus. Under the name of Villeneuve he now announced himself, entered as student of mathematics and physics at one of the colleges, and at a later period took his degrees of M.A. and M.D. in the University of Paris. Under the same name he subsequently wrote and edited various works at Lyons; and it was as M. Villeneuve that he finally became known in the town of Vienne in Dauphiny, where he lived for twelve years engaged in the practice of medicine, and on terms of intimacy with the Archbishop and all the notabilities of the place, both lay and clerical.
As a man of scholarly acquirements Servetus in the first instance probably found employment, and the means of living with some of the typographers of Paris, as reader and corrector of the press, a line of life which he certainly followed for the next three or four years, in the course of which we find notices of him first at Orleans, then at Avignon, and finally at Lyons, one of the chief centres of the printing and publishing business that had been called into such vigorous life by the revival of learning, the discovery of the art of printing with moveable types, and finally and very essentially by the Reformation.