Science in Christian Perspective


Galileo and the Church: Tensions with a 
Message for Today Part Ill
Atkinson College, 
York University Toronto, Ontario, Canada

From: JASA 25 (September 1973): 111-113.
The year of 1973 has been designated Copernican Year in honor of the 500th anniversary of the birth of Copernicus in 1473. In keeping with this commemoration, the Journal ASA offers a four-pan publication of a paper presented by T. H. Leith at the 1972 Convention of the American Scientific Affiliation at York University. Part I appeared in journal ASA 25, 21-24, March 1973. Part H appeared in journal ASA 25, 64-66, June, 1973.

Galileo (1564-1642)

In 1609, the year when Kepler's elliptical orbits were presented to the public, Galileo Galilei was a respected but rather obscure professor in Padua actively seeking, after 17 years in the post an improvement in his position. In that summer he first heard of a Dutch device being exhibited there (it was likely modelled upon an Italian instrument of 1590 about which he had been equally uninformed) and in haste experimented until he had discovered its secret. Constructing a telescope of some ten diameters magnification he proceeded to employ it both intensively for astronomical purposes and to help him secure the position of Chief Mathematician at the University of Pisa (though he agreed that this would be without teaching duties and that he would not settle there) and Philosopher to Cosimo Medici, the Duke of Tuscany, in Florence. This move from Padua, under the protection of the independent Venetian state, he was later to regret for it probably placed him more readily into the hands of the Inquisition.

In 1597, on receiving a copy of the Cosmographic Mystery, Galileo had informed Kepler that "many years ago I became a convert to the Copernican theory". In 1610 his little hook on his telescopic studies, the Sidereal Message first publicly announced his position. It contained evidence of irregularities on the Moon, thus denying the traditional perfection of the heavenly bodies; evidence of many previously invisible stars, indicating that the import of the heavens could scarcely rest upon what the naked eye had observed throughout history; evidence of a lack of noticeable stellar magnification which suggested that the stars were farther away than indicated by past opinion; and evidence of the presence of moons orbiting Jupiter, which discredited the uniqueness of the Earth and strengthened the possibility that it orbited the Sun among the other planets. Later, in 1613, the Academy of the Lynx-eyed in Rome and of which he was a member, published his discoveries at Florence of the phases of Venus, which demonstrated its movement about the Sun, and of sunspots, which suggested imperfections on that body and whose paths also indicated its rotation.

None of these, however, was difficult to reconcile with a Tychonic model as his friends among the Jesuits at once recognized. But Galileo refused to countenance that. Then, between 1613 and 1615, Galileo wrote a series of letters attempting to show that the Bible could he interpreted in a Copernican manner. This evoked speedy reaction because it was his first clear challenge to traditional Biblical scholarship. Why did he take this risky step? Partly, it would seem, from a desire to see the church firmly supportive of the new truths about the world revealed to the careful observer. Partly it was because of his firm conviction that he was right in calling for a new foundation to the philosophy of nature, one with a Copernican outlook and one based upon a proper physics and the quantitative method on which he had been laboring for many years.

Galileo is sometimes seen as a scientist challenging the authority or correctness of Scripture. He was nothing of the kind for he never questioned the harmony of God's revelation in nature and in the Bible; what he did doubt, like Kepler, was the correctness of certain interpretations of what the Bible meant, expounded when other world views and astronomical attitudes were still plausible, and the propriety in many cases of reading any technical meaning into it at all. What was disconcerting to his opponents was the basic attitude toward the Bible and the Church which lay behind this, for it seemed to imply that Biblical teaching was never competent to challenge science and it eroded the authority of the church in matters of Biblical interpretation. If Galileo plead that there could be no conflict between well-founded science and the non(or pre-) scientific language of Scripture, they could reply that no science was so secure as to be beyond question and that, as a scientist, he was incompetent to judge whether passages long used to defend the immobility of the Earth were, in the Hebrew, technical or not. If Galileo wished to tell the Church how to interpret Scripture simply to fit what he took to be a solidly-corroborated scientific doctrine, they could argue that this took ultimate authority from the Church and placed it in the hands of an individual, an approach suited to heretical Protestantism and anathema to the position so clearly taken in reaction by the Council of Trent.

The Dominicans of course saw an additional danger in Galileo's thinking for they were consistently Aristotelian in their natural philosophy. Galileo had, with his espousal of a new physics and of Copernican doctrine, hurled the gauntlet in their direction. From their perspective Galileo was upsetting the entire world order and in particular he was challenging the real synthesis between the Christian faith and Aristotelian philosophy so firmly established since the time of Thomas Aquinas. To the Jesuit followers of Tycho, Galileo also seemed to be making claims for the truth of Copernican doctrine which were unjustified and to be asking the church, of which they were the defenders, to make major concessions on a flimsy scientific basis.

Before long Galileo was hearing from Rome. In the early months of 1615 Cardinal Barberini cautioned Galileo, through a friend, to treat Copernican ideas as fictions. The head of the Jesuit College, Cardinal Bellarmine, a month later was also offering his opinion. In response to a small book by a Carmelite priest, Foscarini, favoring a reconciliation of Biblical interpretation to Copernican ideas, he wrote the author a letter making three points. The first was that the affirmation of the truth of Copernicanism would irritate theologians and Aristotelians, injure the holy faith, and make Scripture false. Secondly, the church, after the Council of Trent had prohibited Biblical exposition which was contrary to the common agreement of the church fathers, could hardly support giving to certain portions of the Bible a sense contrary to that found in its earlier teachers and to all modern scholarship; indeed, a denial of what the church believes to be the clear meaning of Biblical revelation is heresy. Finally, the church would revise its interpretations only if and when the Copernican theory was proven. Within weeks Galileo saw the letter and within months he was in Rome to do battle. 

But as the Tuscan ambassador put it,

this is not the place to come arguing about the Moon, nor in this age, to defend or introduce any novel doctrine.

And, as a friend of Galileo had remarked,

if new things are introduced . . . someone amplifies, another alters . . . Your ideas about the . . . bright and dark areas of the Moon introduce an analogy between that body and the Earth, someone amplifies this to suggest that you are putting people on the Moon, the next person begins to ask how these can be descended from Adam and how they might have come off Noah's ark.

The Church had, of course, a convenient way out, for Galileo has as yet offered no demonstration of the Earth's motion not subject to alternative interpretation. Galileo now essayed to provide one, his notorious argument from the tides which appears to violate his own physics and to be quite incorrect.

It is unlikely that even had it been valid it would have had much effect under the circumstances. The theologians, asked by the Holy Office for an opinion on the merit of the heliocentric doctrine, never considered it and thus took no thought for revising traditional Biblical exegesis. Instead, they judged the idea that the Sun was central in the universe and immobile to be philosophically absurd and formally heretical. The thesis that the Earth had a daily and annual motion, and that it was not central in the cosmos, they declared to be incorrect in philosophy and erroneous in theology. Within days, and less than three weeks after Galileo's arrival in Rome, the Congregation of the Index prohibited all Copernican writings. The Copernican revolution ended, it seemed, for church officialdom in March of 1616.

The Pope now instructed Cardinal Bellarmine to inform Galileo that the belief that the Earth moves about a stationary and central Sun was unscriptural and thus could not be defended or held. If Galileo refused to abandon his error he was also to be told that he could not even teach the Copernican scheme. A long debate has centered around whether Galileo did, in fact, refuse. A purported minute of the meeting indicates that he had received the prohibition, while a letter from Bellarmine to Galileo is quite clear that Galileo had not abjured any opinion on the matter. In any event, Galileo appeared to be defeated for he could no longer defend the doctrine in which he so firmly believed.

Galileo was publicly silent for several years after the disturbing events of 1616 but his private opinion was likely that which he expressed sometime later.

Can anyone question that, when minds given theft freedom by God are placed in abject submission to the will of others, serious unrest will follow? When we are instructed to reject our senses and place them under
the fancies of others? When total incompetents are permitted to judge experts and handle them as they wish? It is these novelties which may well result in ruining commonwealths and subverting the state.

Melanchthon would have been astounded at that final twist! To acquaintances he could he subtly ironic, commenting that he understood how necessary it was to accept the decisions of his superiors, of those led by a higher knowledge than this poor mind could achieve, and then asking them to read his works as poetry or a dream because "I esteem somewhat this vanity of mine."

In 1623 the Academy of the Lynx-Eyed published a brilliant essay on scientific method, entitled The As sayer, and dedicated to Urban VIII the former Cardinal Barberini14. Hearing of Urban's favorable response, Galileo travelled to Rome the following spring to see if he could obtain from the Pope greater freedom to discuss his Copernican thesis. He was told to go ahead but to treat it only as a useful hypothesis because God need not do things in the way which we imagine. Now 60, Galileo began the preparation of his Dialogue Concerning the Two Chief World Systems15 and completed it early in 1630, some six years later. It came from the press in 1632 and was soon suppressed after an ecclesiastical commission, activated by Galileo's opponents, reported that it was really a defence of Copernican doctrine. Its author was called to Rome, charged with violating the injunction of 1616.
Galileo's defence lay in Bellarmine's letter, and the Pope's conversations, allowing him freedom to discuss the doctrine. His opponents brought forward the purported minute indicating that he had been restricted more severely. Galileo replied that he could recall no restraint on his discussing Copernican ideas and that the Dialogue was not a defence of these ideas but instead treated them as hypothesis. However, even if his first plea might be successful the second could hardly he taken as credible. After all, the Dialogue was clearly intended to be a convincing argument for a new world-view and it was aimed at converting the intelligent reader, by reporting the wonders to be learned from nature, to a revision of traditional outlooks. As a result he was found suspect of heresy, required to abjure sincerely and to curse and to detest what the church considered to be error and unscriptnral, and sentenced to house arrest for an unstated term. He was still under this formal imprisonment at his death in 1642's.16

(To be concluded)


14This and other shorter writings by Galileo are to be found in Discoveries and Opinions of Golileo, S. Drake (ed.), New York, 1957. See also the review of this by E. Rosen in Journal of the History of Ideas, 1957, pp. 439-448.
15Diologoe Concerning the Two Chief World Systems, Berkeley, 1953 or Dialogue n the Great World Systems, Chicago, 1953.
16Galileo's methods, life and trial are discussed in Galileo Galilei, L. Geymonat, New York, 1965; Galileo Re-Appraised, C. L. Golino, Berkeley, 1966; La Revolution Astronomiqae, A. Koyre, Paris 1961; The Crime of Galileo, G. de Santillana, Chicago, 1955; Galileo Galilei, R. I. Seager, Oxford, 1966; Galileo, Man of Science, E. MeMullin (ed), New York, 1967; Galileo, Science and the Church, J. J. Langford, Ann Arbor, 1971; Galileo Studies, S. Drake, Ann Arbor, 1970; Etudes Galileenues, A. Koyrc, Paris, 1966; Metaphysics and measurement, A. Koyre, London, 1968; and La Philosophie Naturelle de Galilee, M. Clavelio, Paris, 1968.