In 1611 he visited Rome to display the telescope to the papal court. In 1616 the system of Copernicus was denounced as dangerous to faith, and Galileo, summoned to Rome, was warned not to uphold it or teach it. But in 1632 he published a work written for the nonspecialist, Dialogo … sopra i due massimi sistemi del mondo [dialogue on the two chief systems of the world] (tr. 1661; rev. and ed. by Giorgio de Santillana, 1953; new tr. by Stillman Drake, 1953, rev. 1967); that work, which supported the Copernican system as opposed to the Ptolemaic, marked a turning point in scientific and philosophical thought. Again summoned to Rome, he was tried (1633) by the Inquisition and brought to the point of making an abjuration of all beliefs and writings that held the sun to be the central body and the earth a moving body revolving with the other planets about it. Since 1761, accounts of the trial have concluded with the statement that Galileo, as he arose from his knees, exclaimed sotto voce, "E pur si muove" [nevertheless it does move]. That statement was long considered legendary, but it was discovered written on a portrait of Galileo completed c.1640.
After the Inquisition trial Galileo was sentenced to an enforced residence in Siena. He was later allowed to live in seclusion at Arcetri near Florence, and it is likely that Galileo's statement of defiance was made as he left Siena for Arcetri. In spite of infirmities and, at the last, blindness, Galileo continued the pursuit of scientific truth until his death. His last book, Dialogues Concerning Two New Sciences (tr., 3d ed. 1939, repr. 1952), which contains most of his contributions to physics, appeared in 1638. In 1979 Pope John Paul II asked that the 1633 conviction be annulled. However, since teaching the Copernican theory had been banned in 1616, it was technically possible that a new trial could find Galileo guilty; thus it was suggested that the 1616 prohibition be reversed, and this happened in 1992. The pope concluded that while 17th-century theologians based their decision on the knowledge available to them at the time, they had wronged Galileo by not recognizing the difference between a question relating to scientific investigation and one falling into the realm of doctrine of the faith.
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.