The Church and Galileo

Abstract

THE CHURCH AND GALILEO The Church and Galileo. Edited by Ernan McMullin. [Studies in Science and the Humanities from the Reilly Center for Science, Technology, and Values.] (Notre Dame: University of Notre Dame Press, 2005. Pp. xii, 391. $60.00 cloth ISBN 978-0-268-03483-8; $30.00 paper ISBN 978-0-268-03484-7.) I In 1633, at the end of one of the most famous trials in history, the Inquisition found Galileo vehemently of heresy1 for holding and defending the thesis the earth revolves around the sun and for thinking that one may hold and defend as probable an opinion after it has been declared and defined contrary to the Holy Scripture.2 Vehement suspicion of was a technical term meaning much more than it may sound to modern ears; in fact, it was a specific category of religious crime intermediate in seriousness between formal and mild suspicion of The content of Galileo's suspected heresy was twofold.The first was an astronomical or cosmological claim about physical reality, which Galileo had supported and defended in his Dialogue on the Two Chief World Systems, Ptolemaic and Copernican (1632).The second was a methodological principle or rule about how to proceed in the search for physical truth or the acquisition of natural knowledge; it may be rephrased as the principle Scripture is not an authority and may be disregarded as irrelevant in astronomy and natural philosophy; Galileo had practiced this principle in this book and had justified it explicitly in privately circulated essays in 1613-1616. A number of penalties accompanied this verdict. First, Galileo had to recite immediately an abjuration of the above mentioned errors and heresies.3 Second, the Dialogue was banned. Third, he was condemned to house arrest to the end of his life (1642). Finally, he had to recite the seven penitential psalms once a week for three years. II This condemnation was the climax of a series of events4 started in 1543, when Nicolaus Copernicus published an epoch-making book, On the Revolutions of the Heavenly Spheres, in which he advanced a new argument in favor of the idea the earth revolves around the sun. The Copernican theory immediately came under attack for reasons stemming from astronomical observation, Aristotelian physics, traditional epistemology, and scriptural interpretation. These objections were advanced by astronomers, mathematicians, and natural philosophers, as well as theologians and churchmen, and by Protestants as well as Catholics. Thus, Copernicanism attracted few followers. Galileo, in the first twenty years of his career (1589-1609), was not one of them. His stance toward Copernicanism then was one of indirect pursuit, an attitude is not only weaker than acceptance but also weaker than direct pursuit: his research focused on physics rather than astronomy; he was critical of Aristotelian physics and favorably inclined toward an Archimedean approach; he had intuited Copernicanism was more consistent with the new physics he was developing than was the geostatic theory; but at time, he felt the arguments against Copernicanism were stronger than those in favor of it. However, in 1609, by means of the newly invented telescope, he made several startling discoveries, which he published in The Sidereal Messenger (Venice, 1610): the moon's surface is rough, full of mountains and valleys; innumerable other stars exist besides those visible with the naked eye; the Milky Way and the nebulas are dense collections of large numbers of individual stars; and the planet Jupiter has four moons revolving around it at different distances and with different periods. Soon thereafter, he also discovered the phases of Venus and sunspots, and he published the Sunspot Letters (Rome, 1613). The new telescopic evidence removed most of the observational-astronomical objections against the earth's motion and added new evidence in its favor. …