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But Still, It Moves!



The Galileo affair is prima facie evidence that the scientific pursuit of truth only became possible after physics was liberated from the Aristotelian shackles of the Middle Ages.

Medieval Natural History

In 1543, Nicholas Copernicus, a Polish monk, published his epochal "On the Revolution of the Celestial Orbs". The notion that the earth might revolve around the sun was at least as old as the ancient Greeks, but the geocentric theory, endorsed by Aristotle and given mathematical plausibility by Ptolemy, was the prevailing model until Copernicus. It was given additional credibility by certain passages of Scripture, which affirmed the mobility of sun and the fixity of the earth. Most Church Fathers simply took the geocentric theory for granted. Since the Son of God became incarnate on earth, it was thought fitting that the earth be the centre of the universe.

Since the time of Aristotle, the purpose of astronomy was to save the appearances of celestial phenomena. To the Aristotelian mind, science was an expedient means of organizing data. It had no bearing on the ultimate reality of things. This was a matter for philosophy and theology. Different mathematical devices, such as the Ptolemaic epicycles, could be advanced to predict the movements of the planets, and it was of no concern whether they were objectively true. The only point was to give order to complicated data. All that mattered was which system was most convenient. Very much the same attitude is now prevalent in the modern physics establishment regarding Quantum Theory.

The Aristotelian Cosmos comprised two worlds, the superlunary and the sublunary. The former consisted of the moon and everything beyond; it was perfect and imperishable. The latter was the terrestrial globe and its atmosphere, subject to generation and decay. Use of Ptolemy's methodizing of Aristotle, made it possible to navigate the seas and predict eclipses. There was no practical motivation to give up this successful system for a new, unproved cosmology which not only contradicted common sense (as no less an authority than Francis Bacon averred), but also the obvious meaning of Scripture.

The Copernican Revolution

The notion that the purpose of science was not to give a final account of reality, but merely to save appearances, explains why the Catholic hierarchy initially received Copernicus's theory with equanimity. Astronomy, Physics and mathematics were regarded as insignificant, with neither philosophical nor theological relevance. Copernicus published his book at the urging of two eminent prelates and dedicated it to Pope Paul III, who received it cordially.

That Copernicus believed the heliocentric theory to be an objective description of reality went largely unnoticed. This was partly because he still made reassuring use of Ptolemy's cycles and epicycles. He also borrowed from Aristotle the mistaken notion that the planets must move in circles because that was the only perfect motion. There was, moreover, the famous preface by Osiander, a Protestant who oversaw the printing of the first edition. Osiander knew that Luther and Melanchthon violently opposed any suggestion that the earth revolves around the sun. So he wrote an unsigned preface, which everyone took to be Copernicus's, presenting the theory as a mere mathematical device for charting the movements of the planets in a simpler manner, but one that was not meant to be a definitive description of the heavens.

In reality, Copernicus's book marked a revolution in human thought: one that caught the universities even more off guard than the Church. Copernicus, and others like Kepler and Galileo, began to affirm that the heliocentric hypothesis not only saved the appearances, but was objectively true. This represented a new theory of the nature of theory: to the extent that a hypothesis saves the appearances, to that extent, it should be taken as corresponding with reality.

Galileo's Telescope

Enter Galileo. He held the chair of mathematics at the University of Pisa and later at Padua, where he was nicknamed The Wrangler because he was always starting arguments. He acquired and improved a telescope. Looking through his new spyglass, he made some discoveries which shook the foundations of the Aristotelian cosmos. He saw that the moon was not a perfect sphere, but pock-marked with mountains and valleys, like the earth. Second, and more astonishing, Jupiter had at least four satellites. No longer could it be said that heavenly bodies revolve exclusively around the earth. Finally, he observed the phases of Venus, easy to account for if Venus moves around the sun and not the earth.

The response to these discoveries ranged from enthusiastic to downright hostile. The leading Jesuit astronomer of the day, Christopher Clavius, was sceptical. However, when the Roman college acquired an improved telescope, he saw for himself that Galileo was right about Jupiter's moons, and the Jesuits subsequently confirmed the phases of Venus. Still, Galileo was the man of the hour. In 1611 he made a triumphant visit to Rome, where he was feted by cardinals and granted a private audience by Pope Paul V, who assured him of his support and good will. Cardinal Robert Bellarmine, a Jesuit scholar and inquisitor, was intrigued with Galileo's theories but concerned with the disruption that publication of them could produce in the minds of ordinary Catholics.

Galileo's Campaign

Galileo returned to Florence, where for about two decades, he took upon himself the role of popularizing the Copernican system. Church officials were willing that heliocentrism be taught as a hypothesis and discussed in scientific circles, so long as the faith of the ignorant common people was safeguarded. However, Galileo began to teach his theory loudly and widely, insisting that it was fact. Of course it was not proven, no amount of ground based observational data could ever do that. Nevertheless, the evidence against the Ptolmaic system was decisive. The half-way system of Tycho Brahe, adopted by the Jesuits had nothing to recommend it, except for its supposed metaphysical advantage of keeping the earth at the centre of a Cosmos in which all the other planets orbited the sun.

Cardinal Newman, wrote concerning Galileo's campaign, that:

"had I been brought up in the belief of the immobility of the earth as though a dogma of Revelation, and had associated it in my mind with the incommunicable dignity of man among created beings, with the destinies of the human race, with the locality of purgatory and hell, and other Christian doctrines, and then for the first time had heard of Galileo's thesis .... I should have been at once indignant at its presumption and frightened at its speciousness, as I can never be, at any parallel novelties in other human sciences bearing on religion."
Perhaps Galileo's path  would not have led to the offices of the Inquisition had he been more discrete. However, like many of the Fathers, he was not a tactful person. Moreover, is it proper to be discrete about truth? The examples of Elijah, Jeremiah, John Baptist, Jesus, St Stephen Protomartyr and St Athanasius might make one think not!

When Galileo started his campaign, he enjoyed almost universal good will among the Catholic hierarchy. However, he managed to alienate almost everybody with his caustic manner and aggressive tactics. His position gave the Church authorities no room to manoeuvre: they either had to accept Copernicanism and reinterpret Scripture accordingly; or they had to condemn it. He rejected out of hand the unreasonable compromise which the Church offered him: that Copernicanism might be considered a hypothesis, one even superior to the Ptolemaic system, but one that should not be proposed as objective truth until absolute proof be obtained.

Galileo's belligerence probably had much to do with the fact that he knew there could be no direct proof of heliocentrism. He could not even answer the strongest argument against it: if the earth did orbit the sun, Aristotle had argued, then stellar parallaxes would be observable in the sky. Galileo was not able with the best of his telescopes to discern the slightest stellar parallax. This was because the distance of the nearest star is so unthinkably huge as to make its parallax incredibly small: but such an explanation was implausible at the time.

Galileo's other problem was that he insisted, despite the discoveries of Kepler, that the planets orbit the sun in circles. The Jesuit astronomers could plainly see that this was untenable. Galileo nonetheless launched his campaign with a series of pamphlets and letters which were circulated all over Europe. Along the way, he picked fights with a number of Churchmen on peripheral issues which helped to stack the deck against him.

Scripture and Science

If the debate had been conducted on the subjectivist basis that Astronomy was only concerned with the systemization of data rather than objective reality, it would have been shrugged off by the Church authorities. However, in 1614, Galileo felt that he had to answer the objection that the new objectivist Physics contradicted Scripture. There was, for example, Joshua's command that the sun stand still. Why would Joshua do that if, as Galileo asserted, the sun didn't move at all? Then there were Psalms 92 and 103: "He has made the world firm, not to be moved" and "You fixed the earth upon its foundation, not to be moved forever", not to mention the famous verse in Ecclesiastes. These are not obscure passages, and their literal sense would obviously have to be abandoned if the Copernican system were true.

Galileo addressed this problem in his famous Letter to Castelli. In it, Galileo pointed out that Scripture often makes use of figurative language and is not meant to teach science. This position was eventually accepted by the Church, and even featured in Leo XIII's encyclical, "Providentis-sumus Deus". Galileo accepted the inerrancy of Holy Scripture; but was mindful of Cardinal Baronius's quip that the Bible "is intended to teach us how to go to heaven, not how the heavens go." Galileo also pointed out that both St. Augustine and St. Thomas Aquinas taught that the sacred writers did not intend to teach a system of astronomy.

Unfortunately, in 1616, the year of Galileo's first trial Catholic biblical theology was not very sophisticated.The Church had just been through the Reformation. Catholic theologians were in no mood to entertain hermeneutical injunctions from a layman like Galileo. Nevertheless, Galileo threw caution to the winds, and it was on this point: the transgression of  a layman on the clerical  turf of objective truth, that his enemies were finally able to convict him.

The Opposition Musters

About this time, some members of another order of the Church, the Dominicans, were becoming aware of the Copernican world view, and began to preach against it. In 1613, Father Nicolo Lorini, a professor of ecclesiastical history in Florence, inveighed against the new astronomy, in particular "Ipernicus". He wrote a letter of apology after being reproved. In 1614, another Dominican, Father Tommaso Caccini, who had previously been reprimanded for rabble-rousing, preached a fiery sermon with the text "Ye men of Galilee, why stand ye gazing up into the heaven?" He attacked mathematicians, in particular Copernicus, and science in general as contrary to Christian faith. It should be added that these two were not representative of the order as a whole. The Dominican Preacher General, Father Luigi Maraffi, wrote Galileo an apology, saying "unfortunately I have to answer for all the idiocies that thirty or forty thousand brothers may or actually do commit".

In 1615 Professor Lorini read a copy of Galileo's Letter to Castelli and was disturbed to find that a layman had taken it upon himself to interpret Scripture. He sent an altered copy of the letter to the Inquisition. He made two changes, one of which was from

Still, the inquisitor who read it thought it passable, although open to being misconstrued. The case was dismissed. A month later, Caccini appeared in Rome uninvited, begging the Holy Office to proceed against Galileo. His testimony before the Inquisition was a web of hearsay, innuendo, and deliberate falsehood. The judges of the Inquisition did not believe his story, and the case against Galileo was again dropped.

Nevertheless, the Letter to Castelli. and Caccini's testimony were on the files of the Inquisition, and Rome was buzzing with rumours that the Church was going to condemn both Galileo and Copernicanism. Galileo's friends in the hierarchy, including Cardinal Barberini, the future Urban VIII, warned him not force the issue. Galileo responded by intensifying his campaign to get the Church to accept Copernicanism.

At this point Cardinal Robert Bellarmine, entered the drama. Bellarmine was one of the most important theologians of the Catholic Reformation. As Consultor of the Holy Office of the Inquisition and Master of Controversial Questions, he was unwillingly drawn into the Copernican controversy. In April 1615, he wrote a letter to A. Foscarini,  which amounted to an unofficial statement of the Church's official position. He pointed out that: it was acceptable to maintain Copernicanism as a "working hypothesis"; and added:

"Third, I say that if there were a true demonstration that the sun is at the centre of the world and the earth in the third heaven, and that the sun does not circle the earth but the earth circles the sun, then one would have to proceed with great care in explaining the Scriptures that appear contrary, and say rather that we do not understand them than that what is demonstrated is false. But I will not believe that there is such a demonstration, until it is shown me." [Feldhay: "Galileo and the Church" CUP (1995), page 35]
Bellarmine, in effect, challenged Galileo to prove his theory or stop pestering the Church. Galileo's response was to produce his theory of the tides, which purported to show that the tides are caused by the rotation of the earth. Even some of Galileo's supporters could see that this was patent nonsense. Determined to have a showdown, however, Galileo came to Rome to confront Pope Paul V.

On February 19, 1616 two propositions advanced by Galileo were submitted by the Court of the Inquisition to the Holy Office for advice regarding their orthodoxy:

On February 24 the Holy Office found the first proposition to be:
"foolish and absurd philosophically and formally heretical inasmuch as it expressly contradicts the doctrine of Holy Scripture in many passages...."
and judged that the second should
"receive the same censure in philosophy and, as regards theological truth, to be at least erroneous in faith."
Pope Paul V told Cardinal Bellarmine to warn Galileo that if he did not abstain from discussing his theory as objective fact, he would be imprisoned. Galileo was intimidated by this warning, and kept quiet for sixteen years.

Fortunately this verdict was suppressed, under pressure of more cautious Cardinals and was not published until 1633, when Galileo forced a second showdown. A milder decree, which did not include the word "heretical", was issued and Galileo was summoned before the Holy Office. A report was put into the files of the Holy Office for February 26, 1616, stating that Galileo was told to relinquish Copernicanism and commanded "to abstain altogether from teaching or defending this opinion and doctrine, and even from discussing it." It is still unresolved as to whether this document is genuine, or was forged and slipped into the files by some unscrupulous curial official. At Galileo's request, Bellarmine gave him a certificate which only forbade him to "hold or defend" the theory. When, sixteen years later, Galileo wrote his famous Dialogue on the Two Great World Systems, he did not violate Bellarmine's injunction. However, he did violate the command recorded in the controversial secret minute. This was used against him at the second trial in 1633.

Papal Overreaching

When, in 1623, Galileo's friend and supporter Cardinal Barberini was elected Pope Urban VIII, Galileo thought that he could get the decree of 1616 lifted. Urban gave several private audiences to Galileo, during which they discussed the Copernican theory. Urban was a vain, irascible man who, in the manner of a late prince of the Renaissance, thought he was qualified to make pronouncements in all areas of human knowledge. At one audience, he told Galileo that the Church did not define Copernicanism as heretical and would never do so. He suggested that Galileo publish his work, but frame it as an interesting hypothesis rather than propose it as a theory of objective reality. At the same time, he opined that no amount of quibbling about the planets could touch on objective reality: only God could know how the solar system was really disposed.

Galileo was correct to reject such half baked philosophizing, but he miscalculated Urban's tolerance in writing "The Great Dialogue". In it he ridiculed the defenders of Aristotle and Ptolemy by representing them as a comical figure "Simplicio". Moreover, at the conclusion of the Dialogue he put words that had been spoken to him in private by the Pope into Simplico's mouth: "Just as God chose to make the world in exactly the way it pleased Him, so He chooses to make it appear to operate in the way that He pleases. These have no clear relationship. Observation and experiment can tell us nothing about objective reality." [I paraphrase].

In doing so, Galileo fell into the hands of his enemies. They convinced the Pope that Galileo intended to mock him. The very person that Galileo needed as his protector was turned against him. At the same time, Galileo alienated the Jesuit order with his violent attacks on one of its astronomers, Horatio Grassi, over the nature of comets. In fact, the Jesuit was right: comets are not "exhalations of the atmosphere", as Galileo supposed.

Unjust Condemnation

The result of these ill advised tactics was the famous second trial. Galileo, an old sick man, was summoned before the Inquisition in Rome. The proceedings were not of the highest quality. Galileo's enemies produced the secret, perhaps forged, document that absolutely forbade the teaching or discussion of heliocentrism, and Galileo lied about the circumstances of the publication of his book. The trial did not address the scientific merits of the case, it centred on whether or not Galileo had disobeyed an official order. It was suggested that he admit to some wrongdoing, and he would get off lightly. He agreed to tone down the Dialogue, pleading that he had been carried away by his own arguments.

The Inquisition, on June 22, 1633, decreed that Galileo had rendered himself "vehemently suspected of heresy." He was to renounce his errors before the Inquisition, which he did, and be placed under house arrest. The choice of words was debatable, as Copernicanism had never been declared heretical by the Magisterium. In any event, Galileo was sentenced to abjure the theory and to keep silent on the subject for the rest of his life.

Galileo's condemnation was clearly unjust. Just as clearly, Galileo asked for some of the trouble that he got himself into.

Implications for the Magisterium

Manifestly, the sorry story detailed does not impugn the infallibility of Catholic dogma. Heliocentrism was never declared a heresy by the Magisterium. The sentence of 1633 was not irreformable. Galileo's works were eventually removed from the Index, and at the behest of Pius VII, the Holy Office granted an imprimatur to the work of Canon Settele, in which Copernicanism was presented as objective fact, not just a convenient ruse.

Nevertheless, the story does show how Church authorities can easily mistake "secular common sense" for Sacred Tradition and defend the former, to the extent of using intimidation and attempting to suppress the truth. It is my contention that this is exactly what is now being done in the field of friendship, marriage, gender, sexuality and reproductive ethics.

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