Page:The American Cyclopædia (1879) Volume VII.djvu/580

This was followed by one to Christina, grand duchess dowager of Tuscany, reiterating his views, and supporting them by quotations from the writings of the fathers. A Dominican, Lorini, laid a copy of the Castelli letter before the Roman inquisition in February, 1615, but the inquisitors refused to act in the matter, remarking that by confining himself to the system and its demonstration, and letting alone the Scriptures, Galileo would be secure from molestation. His enemies, however, continued their intrigues, and about the end of 1615 he went to Rome, either to obtain a formal sanction of his opinions, or in obedience to a summons. His case came again before the holy office in February, 1616. He was charged with teaching that the sun is the centre of the planetary system, and interpreting Scripture to suit his own theory. The qualifiers of the inquisition pronounced the obnoxious doctrines “formally heretical, because expressly contrary to Holy Scriptures.” Galileo's letters to Castelli and the grand duchess, Copernicus's work on the revolution of the heavenly bodies, and Kepler's epitome of the Copernican theory, were placed on the Index Expurgatorius, whence they were not removed until the time of Benedict XIV.; and Galileo himself was forbidden ever again to teach the motion of the earth and the stability of the sun. Thenceforward he was not permitted to express himself as though Copernicanism were, in the words of the Roman curia, “an actually grounded hypothesis.” But he was permitted and encouraged to use the hypothesis most actively as his clue to fresh scientific results, and to treat with the most ample justice the scientific arguments for and against. He was permitted to maintain that Copernicanism was scientifically likely in the highest possible degree; but he was not at liberty to teach expressly that it had received absolute and irrefragable proof. He had an audience of the pope, however, who assured him of his protection, and in 1617 he returned to Florence. Sickness prevented him from observing the three comets which appeared in 1618, but he entered warmly into discussions about them, and is supposed to have had the chief share in a lecture delivered by his friend Guiducci and printed in 1619, in which they are held to be only meteors. This discourse was attacked by the Jesuit Grassi under the pseudonyme of Lotario Sarsi, and defended by Galileo in his Saggiatore (“Assayer”), one of the most beautifully written of his works. On the accession of his friend Cardinal Barberini to the pontificate under the title of Urban VIII., he went to Rome to offer his congratulations, arriving in the spring of 1624, and receiving during the two months that he remained every mark of esteem and liberality. The pope granted him a pension of 100 crowns, and one of 60 crowns to his son. He now set about composing a work in which he might sum up all the arguments for and against his favorite theory. It was written in the form of dialogues, and accompanied by a preface in which he protested ironically against the idea that the decision of the inquisition in 1616 was rendered through ignorance or passion. He says that, on the contrary, its officers listened with attention to his statement of the scientific arguments on which his theory was based, and maintains that the grounds upon which this decision was justified were entirely religious. The book was published at Florence in 1632 under the title of “Dialogue on the two Principal Systems of the World, the Ptolemaic and Copernican.” This being regarded as a violation of the injunction, Galileo was ordered to appear in person at Rome, where he arrived in February, 1633, and took up his quarters with the Tuscan ambassador. His trial was short. The principal ground of complaint was the disobedience of the command of 1616, and the scientific reasons which Galileo again urged in support of his theory were not appreciated any better than before, but were met with religious arguments. The sentence was solemnly pronounced June 22. It set forth the offence of the accused in teaching a condemned proposition, violating his pledge, and obtaining a sanction for his book by improper means, declared him to be vehemently suspected of heresy, required him to abjure his errors and all other heresies against the Catholic church, prohibited his “Dialogue,” and condemned him to be imprisoned at the inquisition during pleasure, and to recite once a week for three years the seven penitential psalms. Galileo made his abjuration with all the formality which commonly attended such proceedings. Clad in sackcloth and kneeling, he swore upon the Gospels never again to teach the earth's motion and the sun's stability; he declared his detestation of the proscribed opinions, and promised to perform the penance laid upon him. Then rising from the ground, he is said to have exclaimed in an under tone: E pur si muove—“It does move, for all that!” After four days' confinement under the eyes of the holy office, Galileo returned to the Tuscan ambassador's, but for the rest of his life he was kept under surveillance. He passed some time in Siena, in the archbishop's palace, and in December reëntered his own house at Arcetri, near Florence, where he remained until the close of his life. The death of his favorite daughter Maria so affected his already broken health that he begged permission to visit Florence for medical assistance. It was only after four years (1638) that he obtained it, and then under severe restrictions. He seems now to have paid little attention to astronomy, but employed himself in other branches of natural philosophy. In 1638 his book of “Dialogues on Local Motion,” completed two years before, which he prized above all his other works, was printed at Amsterdam by Louis Elzevir. In 1636 also he discovered the moon's diurnal libration. In 1637 a disease which had impaired his right eye for some years attacked the left also, and in a few months