By John Heilbron
What Galileo believed about providence, miracles, and salvation, is hard to say. It may not matter. Throughout his life he functioned as the good Catholic he claimed to be; and he received many benefits from the church before and after the affair that brought him to his knees before the Holy Inquisition in 1633.
First among these benefits was education. Galileo studied for a few years at the convent of Vallombrosa (a Benedictine order) near Florence. He loved the place and had entered his novitiate when his father removed him from the temptation. Later the Vallombrosans gave him his first important job teaching mathematics. He probably lived briefly at the Benedictine convent of Santa Giustina in Padua just after taking up a professorship at Venice’s university there in 1592. He may have taught at Santa Giustina and from its ranks recruited his most faithful disciple, Dom Benedetto Castelli.
The largest and ablest collection of mathematicians in Italy belonged to the Society of Jesus. When he started serious study of mathematics, Galileo sought and obtained the advice and approval of their leader, Father Christopher Clavius. He had to break off relations in 1606, when the Venetian state expelled the Jesuits from its territories. Galileo restored the connection soon after returning to Florence in 1610 as “Mathematician and Philosopher to the Grand Duke of Tuscany.” Again he had an urgent need for Clavius’ endorsement. The astonishing discoveries he had made in 1609/10 by turning his telescope on the heavens challenged credulity. By the end of 1610 he had the confirmation he wanted. Clavius’ group of mathematicians invited him to their headquarters in Rome to celebrate the “message from the stars,” as Galileo had entitled the book in which he had announced his discoveries, and to toast the messenger.
Galileo’s other benefits from the Church included the large salary he enjoyed as court mathematician and philosopher, which came from ecclesiastical revenues, and a papal pension for his son. The son declined on discovering that its beneficiary had to wear a tonsure, and Galileo, having no such reservation, took it himself. In the hope of relieving his chronic illnesses, he made pilgrimages to Loreto. To relieve himself of his two illegitimate daughters, he put them in a nunnery. When old and blind and confined to his villa, members of religious orders comforted and read to him. And throughout his life he had many friends, disciples, and patrons among ecclesiastics.
His late-in-life comforters were not Jesuits. Obliged to teach the physics of Aristotle, in which the earth stands still at the center of the world, they could not endorse the Copernican system, which Galileo believed his discoveries proved. That did not stop them from becoming experts in telescopic astronomy. Galileo did not like the competition and attacked the Jesuits unfairly. That was a mistake. They did not help him when he ran into an order of priests who did not like mathematics. These were the Dominicans, who ran the machinery of the Inquisition.
Some of their firebrands preached that since Copernican notions conflicted with Joshua’s order to the sun to stand still, they might be heretical. Galileo hurried to Rome in 1615 to clear himself and Copernicanism. Early in 1616 the Inquisition found that Copernicanism was contrary to scripture and philosophically absurd; the Congregation of the Index thereupon banned Copernicus’ masterpiece pending correction and other works altogether; but it did not mention Galileo. Instead, on papal orders, the chief theologian of the Inquisition, the Jesuit Cardinal (now Saint) Robert Bellarmine, summoned Galileo to hear the decree of the Index and to receive, in private, a personal injunction not to teach or hold the Copernican theory in any way whatsoever.
Galileo obeyed this instruction unti