At the French university Servetus made the acquaintance of one Juan de Quintana who shortly afterwards became the confessor of the Emperor Charles V. During the Middle Ages, an imperial coronation was a good deal like a modern international exhibition. When Charles was crowned in Bologna in the year 1530, Quintana took his friend Michael with him as his secretary and the bright young Spaniard saw all there was to be seen. Like so many men of his time, he was of an insatiable curiosity and he spent the next ten years dabbling in an infinite variety of subjects, medicine, astronomy, astrology, Hebrew, Greek, and, most fatal of all, theology. He was a very competent doctor and in the pursuit of his theological studies he hit upon the idea of the circulation of the blood. It is to be found in the fifteenth chapter of the first one of his books against the doctrine of the Trinity. It shows the one-sidedness of the theological mind of the sixteenth century that none of those who examined the works of Servetus ever discovered that this man had made one of the greatest discoveries of all ages. If only Servetus had stuck to his medical practice! He might have died peacefully in his bed at a ripe old age. But he simply could not keep away from the burning questions of his day, and having access to the printing shops of Lyons, he began to give vent to his opinions upon sundry subjects. Nowadays a generous millionaire can persuade a college to change its name from Trinity College to that of a popular brand of tobacco and nothing happens. The press says, “Isn’t it good of Mr. Dingus to be so generous with his money!” and the public at large shouts “Amen!” In a world which seems to have lost all capacity for being shocked by such a thing as blasphemy, it is not easy to write of a time when the mere suspicion that one of its fellow citizens had spoken disrespectfully of the Trinity would throw an entire community into a state of panic. But unless we fully appreciate this fact, we shall never be able to understand the horror in which Servetus was held by all good Christians of the first half of the sixteenth century. And yet he was by no means a radical. He was what today we would call a liberal. He rejected the old belief in the Trinity as held both by the Protestants and the Catholics, but he believed so sincerely (one feels inclined to say, so naïvely) in the correctness of his own views, that he committed the grave error of writing letters to Calvin suggesting that he be allowed to visit Geneva for a personal interview and a thorough discussion of the entire problem. He was not invited.