doctrine implied the confirmation of the system of Copernicus and the demonstration of the earth's motion, which were no longer reserved for mathematicians only, but made intelligible to all by a series of experiments. Here was an innovation calculated to alarm the theologians. A system that might be regarded as inoffensive so long as it was only a mathematical hypothesis, useful to men of science in their researches, became a very different thing on being transformed into a physical truth accessible to the senses and pregnant with consequences touching the plurality of worlds and the aim of creation. Hence the apparent triumph of Galileo hid from view perils the magnitude of which at first eluded his penetrating mind. While he was giving himself up, with perhaps over-much confidence, to the pleasure of success, and was yielding too easily to his habitual temptation to answer objections with sarcasm, the ecclesiastical authority quietly set on foot an inquiry into the orthodoxy of his opinions. Cardinal Bellarmin, probably in the name of his colleagues of the Inquisition, asked of the members of the Roman College (without mentioning Galileo's name) what was to be thought of the astronomical observations that had recently been promulgated by a distinguished mathematician.
This is the first symptom that we have been able to discover of the intervention of theology in the examination of Galileo's scientific opinions. The response of the Roman College was favorable to him; but, from that moment forward, the alarm was sounded, and the Inquisition never lost sight of him. Though the sovereign pontiff, to whom he was presented by the Tuscan embassador, received him with great courtesy, not allowing him to utter even a word on bended knees, yet the Holy Office, even before he had quitted Rome, inquired of the tribunal at Padua whether, in the action brought against Cesare Cremonini for certain philosophical indiscretions, there might not be something to compromise Galileo. A direct personal attack, inspired by an over-weening zeal, quickly followed these early suspicions. On his return to Florence, Galileo took up his labors afresh in the pleasant solitudes of the Belvedere, placed at his service by the kind hospitality of the grand-duke; there he received his friends and pupils, who, on departing from these conversaziones, propagated his doctrines. At this a Dominican friar, Thomas Caccini, took umbrage, and, in a sermon delivered at Santa Maria Nuova on the miracle of Joshua, he suddenly exclaimed, "" The friar doubtless had heard of a conversation held at the court in presence of the grand-duchess dowager Christine of Lorraine, and the Archduchess Madeleine of Austria, in the course of which Father Castelli, a pupil of Galileo, had endeavored to prove, to the great satisfaction of his hearers, that one might believe in the earth's motion without questioning the authenticity of Joshua's miracle. Upon this subject Galileo addressed to his pupil a famous letter, in which he