Galileo's brilliant work in mechanics and his great popularity—for his lectures were thronged—combined with his skilled and witty attacks upon the accepted scientific ideas of the age, embittered and antagonized many who were both conservative and jealous.[232] The Jesuits particularly resented his influence and power, for they claimed the leadership in the educational world and were jealous of intruders. Furthermore, they were bound by the decree of the fiftieth General Congregation of their society in 1593 to defend Aristotle, a decree strictly enforced.[233] While a few of the Jesuits were friendly disposed to Galileo at first, the controversies in which he and they became involved and their bitter attacks upon him made him feel by 1633 that they were among his chief enemies.[234]
Early in 1609, Galileo heard a rumor of a spy-glass having been made in Flanders, and proceeded to work one out for himself according to the laws of perspective. The fifth telescope that he made magnified thirty diameters, and it was with such instruments of his own manufacture that he made in the next three years his famous discoveries: Jupiter's four satellites (which he named the Medicean Planets), Saturn's "tripartite" character (the rings were not recognized as such for several decades thereafter), the stars of the Milky Way, the crescent form of Venus, the mountains of the moon, many more fixed stars, and the spots on the sun. Popular interest waxed with each new discovery and from all sides came requests for telescopes; yet there were those who absolutely refused even to look through a telescope lest they be compelled to admit Aristotle was mistaken, and others claimed that Jupiter's moons were merely defects in the instrument. The formal announcement of the first of these discoveries was made in the Sidereus Nuncius (1610), a book that aroused no little opposition. Kepler, however, had it reprinted at once in Prague with a long appreciative preface of his own.[235]
The following March Galileo went to Rome to show his discoveries and was received with the utmost distinction by princes and church dignitaries alike. A commission of four scientific members of the Roman College had previously examined his claims at Cardinal Bellarmin's suggestion, and had admitted their truth. Now Pope Paul V gave him long audiences; the Academia dei Lincei elected him a member, and everywhere he was acclaimed. Nevertheless his name appears on the secret books of the Holy Office as early as May of that year (1611).[236] Already he was a suspect.
His Delle Macchie Solari (1611) brought on a sharp contest over the question of priority of discovery between him and the Jesuit father, Christopher Scheiner of Ingolstadt, from which Galileo emerged victorious and more disliked than before by that order. Opposition was becoming active; Father Castelli, for instance, the professor of mathematics at Pisa and Galileo's intimate friend, was forbidden to discuss in his lectures the double motion of the earth or even to hint at its probability. This same father wrote to his friend early in December, 1613, to tell him of a dinner-table conversation on this matter at the Tuscan Court, then wintering at Pisa. Castelli told how the Dowager Grand Duchess Cristina had had her religious scruples aroused by a remark that the earth's motion must be wrong because it contradicted the Scriptures, a statement that he had tried to refute.[237] Galileo wrote in reply (December 21, 1613), the letter[238] that was to cause him endless trouble, in which he marked out the boundaries between science and religion and declared it a mistake to take the literal interpretation of passages in Scripture that were obviously written according to the understanding of the common people. He pointed out in addition how futile the miracle of the sun's standing still was as an argument against the Copernican doctrine for, even according to the Ptolemaic system, not the sun but the primum mobile must be stayed for the day to be lengthened.
Father Castelli allowed others to read and to copy this supposedly private letter; copies went from hand to hand in Florence and discussion ran high. On the fourth Sunday in December, 1614, Father Caccini of the Dominicans preached a sermon in the church of S.M. Novella on Joshua's miracle, in which he sharply denounced the Copernican doctrine taught by Galileo as heretical, so he believed.[239] The Copernicans found a Neapolitan Jesuit who replied to Caccini the following Sunday from the pulpit of the Duomo.[240]
In February (1615), came the formal denunciation of Galileo to the Holy Office at Rome by Father Lorini, a Dominican associate of Caccini's at the Convent San Marco. The father sent with his "friendly warning," a copy of the letter to Castelli charging that it contained "many propositions which were either suspect or temerarious," and, he added, "though the Galileisti were good Christians they were rather stubborn and obstinate in their opinions."[241] The machinery of the Inquisition began secretly to turn. The authorities failed to get the original of the letter, for Castelli had returned that to Galileo at the latter's request.[242] Pope Paul sent word to Father Caccini to appear before the Holy Office in Rome to depose on this matter of Galileo's errors "pro exoneratione suæ conscientiæ."[243] This he did "freely" in March and was of course sworn to secrecy. He named a certain nobleman, a Copernican, as the source of his information about Galileo, for he did not know the latter even by sight. This nobleman was by order of the Pope examined in November after some delay by the Inquisitor at Florence. His testimony was to the effect that he considered Galileo the best of Catholics.[244]
Meanwhile the Consultors of the Holy Office had examined Lorini's copy of the letter and reported the finding of only three objectionable places all of which, they stated, could be amended by changing certain doubtful phrases; otherwise it did not deviate from the true faith. It is interesting to note that the copy they had differed in many minor respects from the original letter, and in one place heightened a passage with which the Examiners found fault as imputing falsehood to the Scriptures although they are infallible.[245] Galileo's own statement ran that there were many passages in the Scriptures which according to the literal meaning of the words, "hanno aspetto diverso dal vero...." The copy read, "molte propositioni falso quanto al nudo senso delle parole."
Rumors of trouble reached Galileo and, urged on by his friends, in 1615 he wrote a long formal elaboration of the earlier letter, addressing this one to the Dowager Grand Duchess, but he had only added fuel to the fire. At the end of the year he voluntarily went to Rome, regardless of any possible danger to himself, to see if he could not prevent a condemnation of the doctrine.[246] It came as a decided surprise to him to receive an order to appear before Cardinal Bellarmin on February 26, 1616,[2] and there to learn that the Holy Office had already condemned it two days before. He was told that the Holy Office had declared: first, "that the proposition that the sun is the center of the universe and is immobile is foolish and absurd in philosophy and formally heretical since it contradicts the express words of the Scriptures in many places, according to the meaning of the words and the common interpretation and sense of the Fathers and the doctors of theology; and, secondly, that the proposition that the earth is not the center of the universe nor immobile receives the same censure in philosophy and in regard to its theological truth, it at least is erroneous in Faith."[247]
Exactly what was said at that meeting between the two men became the crucial point in Galileo's trial sixteen years later, hence a somewhat detailed study is important. At the meeting of the Congregation on February 25th, the Pope ordered Cardinal Bellarmin to summon Galileo and, in the presence of a notary and witnesses lest he should prove recusant, warn him to abandon the condemned opinion and in every way to abstain from teaching, defending or discussing it; if he did not acquiesce, he was to be imprisoned.[248] The Secret Archives of the Vatican contain a minute reporting this interview (dated February 26, 1616), in which the Cardinal is said to have ordered Galileo to relinquish this condemned proposition, "nec eam de cætero, quovis modo, teneat, doceat aut defendat, verbo aut scriptis," and that Galileo promised to obey.[249] Rumors evidently were rife in Rome at the time as to what had happened at this secret interview, for Galileo wrote to the Cardinal in May asking for a statement of what actually had occurred so that he might silence his enemies. The Cardinal replied: