It was during his first residence of about two years at Paris, 1532-1534, that he made the acquaintance of the man who became in the end his most implacable enemy, and the immediate cause of his untimely and cruel death. This was no other than the celebrated John Calvin, then a young man and about the same age as himself. Partially emancipated from the fetters of the faith in which he had been born and bred, but not less firmly bound in others of his own fashioning, Calvin had already attracted the notice of his friends and the public by his natural abilities and his scholarly acquirements, and been pointed out as likely to influence the progress of the Reformation in his native France. Hearing of Calvin’s presence in Paris, Servetus as Villeneuve must have sought him out, and, still full of the familiar theological subject, have made an attempt upon him as he had already done upon Œcolampadius and the others, for countenance and approval in the discovery he had made of what he believed to be the true saving Christian faith. But with no better success we must conclude; for though the two young men met oftener than once in private, it was without coming to any agreement. They had, therefore, actually resolved on a public discussion, with a view to the voidance of their theological differences. This, however, never came to pass. Such an exhibition, indeed, could not have taken place at the time without danger to both. Calvin, in his young zeal, and for what he held to be the honour of God, would have faced the danger, but the individual known to his Parisian friends and Calvin as Michel Villeneuve must have seen on afterthought that he could make no public appearance as defender of the _outré_ opinions he entertained, without betraying the Michael Serveto of the De Trinitatis Erroribus and Dialogues who lay hidden behind the adopted name; and this he knew would be not only to disconcert all his present plans, but assuredly to compromise his life. Calvin, we must presume, had not at this time heard of Servetus’s books; very certainly he had not read them; for one so acute and well-informed on theological matters as he, would not have been more than a few minutes face to face with their author without detecting him. But we find no hint in Calvin’s writings that he then surmised who Villeneuve, his Parisian acquaintance, really was, and conclude that he lived for a dozen years or more without suspecting that the individual he discovered as Michael Serveto of the Book on Trinitarian Error in his correspondent of Vienne, of the year 1546, was the same Villeneuve he had known in Paris in 1534.