Galileo affair.html



Galileo before the Holy Office, a 19th century painting by Joseph-Nicolas Robert-Fleury

The Galileo affair, in which Galileo Galilei came into conflict with the Catholic Church over his support of Copernican astronomy, is often considered a defining moment in the history of the relationship between religion and science.^{citation needed}

In 1610, Galileo published his Sidereus Nuncius (Starry Messenger), describing the surprising observations that he had made with the new telescope. These and other discoveries exposed major difficulties with the understanding of the heavens that had been held since antiquity, and raised new interest in radical teachings such as the heliocentric theory of Copernicus.

In reaction, many scholars attacked the theory because it seemingly contradicted several passages of Scripture. Galileo's part in the controversies over theology, astronomy, and philosophy culminated in his trial and sentencing in 1633 on a grave suspicion of heresy.

The 1600 revolution in cosmology

Galileo began his telescopic observations in the later part of 1609, and by March of 1610 was able to publish a small book, The Starry Messenger (Sidereus Nuncius), relating some discoveries that had not been dreamed of in the philosophy of the time: mountains on the Moon, lesser moons in orbit around Jupiter, and the resolution of what had been thought cloudy masses in the sky (nebulae) into collections of stars too faint to see individually. Other observations followed, including the phases of Venus and the existence of sunspots.

None of these findings, that were difficult at first for other astronomers to verify, proved that the Earth moved, or directly contradicted Christian doctrine. However, they caused difficulties for theologians and for natural philosophers (the name given to scientists at the time), as they contradicted the scientific and philosophical ideas of the time, which were based on those of Aristotle, whose teachings were and are closely associated with the Catholic Church.

Jesuit astronomers, experts both in Church teachings and in natural philosophy, were at first skeptical and hostile to the new ideas, however, within a year or two the availability of good telescopes enabled them to repeat the observations. In 1611 Galileo visited the Collegium Romanum in Rome, where the Jesuit astronomers by that time had repeated his observations. Christoph Grienberger, one of the Jesuit scholars on the faculty, sympathized with Galileo’s theories, but was asked to defend the Aristotelian viewpoint by Claudio Acquaviva, the Father General of the Jesuits. Not all of Galileo's claims were completely accepted: Christopher Clavius, the most distinguished astronomer of his age, never was reconciled to the idea of mountains on the Moon, and outside the Collegium many still disputed the reality of the observations. In a letter to Kepler of August 1610¹, Galileo complained that some of the philosophers who opposed his discoveries had refused even to look through a telescope².

Galileo became involved in a dispute over priority in the discovery of sunspots with Christoph Scheiner, a prominent Jesuit. This became a bitter lifelong feud. Oddly, neither of them was right; there can be little doubt that the first observations were by David Fabricius and his son Johannes.

At this time, Galileo also engaged in a dispute over the reasons that objects float or sink in water, siding with Archimedes against Aristotle. The debate was unfriendly, and Galileo's blunt and sometimes sarcastic style, though not extraordinary in academic debates of the time, made him enemies. During this controversy one of Galileo's friends, the painter, Lodovico Cardi da Cigoli, informed him that a group of malicious opponents, which Cigoli subsequently referred to derisively as "the Pigeon league",³ was plotting to cause him trouble over the motion of the earth, or anything else that would serve the purpose.⁴ According to Cigoli, one of the plotters had asked a priest to denounce Galileo's views from the pulpit, but the latter had refused. Nevertheless, three years later another priest, Tommaso Caccini, did in fact do precisely that, as described below.

The Bible argument

From antiquity, the majority of people subscribed to the Ptolemaic theory of geocentrism that the earth was the center of the universe and that all heavenly bodies revolved around the earth. This theory accorded with available scientific knowledge at the time, agreed with a literal interpretation of scripture in several places, such as 1 Chronicles 16:30, Psalm 93:1, Psalm 96:10, Psalm 104:5, and Ecclesiastes 1:5. Further, since in the Incarnation the Son of God had descended to the earth and become man, it seemed fitting that the earth be the center around which all other celestial bodies moved. Heliocentrism, the theory that the earth revolved around the sun, contradicted both geocentrism and the prevailing theological support of the theory.

One of the first suggestions of heresy that Galileo had to deal with came in 1613 from a professor of philosophy, Cosimo Boscaglia, who was neither a theologian nor a priest. In conversation with Galileo's patron, Cosimo II de' Medici, Boscaglia gave the opinion that the telescopic discoveries were valid, but the motion of the Earth was obviously contrary to Scripture. Galileo was defended on the spot by a Benedictine abbot, Benedetto Castelli, who was also a professor of mathematics and a former student of Galileo's. This exchange, reported to Galileo by Castelli, led Galileo to write a letter to Castelli, expounding his views on what he considered the most appropriate way of treating scriptural passages which made assertions about natural phenomena.⁵ Later, in 1615, he expanded this into his much longer Letter to the Grand Duchess Christina.⁶

Tommaso Caccini, a Dominican friar, appears to have made the first dangerous attack on Galileo. Preaching a sermon in Florence at the end of 1614, he denounced Galileo, his associates, and mathematicians in general (a category that included astronomers). The biblical text for the sermon on that day was Joshua 10, in which Joshua makes the Sun stand still; this was the story that Castelli had had to interpret for the Medici family the year before. It is said, though it is not verifiable, that Caccini also used the passage "Ye men of Galilee, why stand ye gazing up into heaven?"⁷

First meetings with theological authorities

The Church officials were willing to let heliocentrism be taught as a hypothesis and discussed in scientific circles, so long as the faith of the ordinary people was safeguarded. But Galileo insisted that it was proven fact, and therefore had to prove his theory.^{citation needed}

In late 1614 or early 1615, one of Caccini's fellow Dominicans, Niccolò Lorini, acquired a copy of Galileo's letter to Castelli, which he considered of sufficiently doubtful orthodoxy to bring to the attention of the Inquisition. In February 1615 he accordingly sent a copy to the Secretary of the Inquisition, Cardinal Paolo Emilio Sfondrati, with a covering letter critical of Galileo's supporters.⁸

On March 19th, Caccini arrived at the Inquisition's offices in Rome to denounce Galileo for his Copernicanism and various other alleged heresies supposedly being spread by his pupils⁹.

Galileo soon heard reports that Lorini had obtained a copy of his letter to Castelli and had, according to the reports, been claiming that it contained many heresies. He also heard that Caccini had gone to Rome and suspected him of trying to stir up trouble with Lorini's copy of the letter.¹⁰. As 1615 wore on he became more concerned, and eventually determined to go to Rome as soon as his health permitted, which it did at the end of the year. By presenting his case there, he hoped to clear his name of any suspicion of heresy, and to persuade the Church authorities not to suppress heliocentric ideas. In this he was acting against the advice of friends and allies, including Piero Guicciardini, the Tuscan ambassador to Rome.

Bellarmine's view

Robert Cardinal Bellarmine, one of the most respected Catholic theologians of the time, was called on to adjudicate the dispute between Galileo and his opponents, including both religious zealots and secular university professors. The question of heliocentrism had first been raised with Cardinal Bellarmine, in the case of Paolo Antonio Foscarini, a Carmelite father; Foscarini had published a book, Lettera ... sopra l'opinione ... del Copernico, which took the dangerous step of attempting to reconcile Copernicus with the biblical passages that seemed to be in contradiction. Bellarmine at first expressed the opinion that Copernicus would not be banned, but would at most require some editing to assure that the heliocentric idea was presented as purely hypothetical.^{citation needed}

Foscarini sent a copy of his book to Bellarmine, who replied in a letter on April 12, 1615, addressed to both Foscarini and Galileo. In this he stated that the heliocentric ideas were "a very dangerous thing, not only by irritating all the philosophers and scholastic theologians, but also by injuring our holy faith and rendering the Holy Scriptures false." Moreover, while the matter was not inherently a matter of faith, it became one "on the part of the ones who have spoken", namely "the holy Fathers and all the Latin and Greek commentators." He conceded that if there were positive proof, "then it would be necessary to proceed with great caution in explaining the passages of Scripture which seemed contrary, and we would rather have to say that we did not understand them than to say that something was false which has been demonstrated." He did not, however, consider this to be a serious possibility. His final argument was that the motion of the Sun could not be a mere appearance, as the shore appears to recede when one sails away from it, because everyone perceives the latter as a mere appearance, while no one so perceives the former.

Bellarmine found no problem with heliocentrism so long as it was treated purely as hypothesis and not as an absolute truth, unless there was conclusive proof. This put Galileo in a difficult position, as he had many powerful arguments but no "conclusive" proof^{citation needed} for the truth of his position^{citation needed}. In fact, his theories had gaps^{citation needed} and errors^{citation needed}, as is the usual condition of all radically new scientific work.^{citation needed}

Inquisition examination

On February 19, 1616, the Inquisition asked a commission of theologians, known as qualifiers, about the propositions of the heliocentric view of the universe.¹¹ Historians of the Galileo affair have offered different accounts of why the matter was referred to the qualifiers at this time. Beretta points out that the Inquisition had taken a deposition from Gianozzi Attavanti in November, 1615,¹² as part of its investigation into the denunciations of Galileo by Lorini and Caccini. In this deposition, Attavanti confirmed that Galileo had advocated the Copernican doctrines of a stationary Sun and a mobile Earth, and as a consequence the Tribunal of the Inquisition would have eventually needed to determine the theological status of those doctrines. It is however possible, as surmised by the Tuscan ambassador, Piero Guiccardini, in a letter to the Grand Duke,¹³ that the actual referral may have been precipitated by Galileo's aggressive campaign to prevent the condemnation of Copernicanism.¹⁴

On February 24 the Qualifiers delivered their unanimous report: the idea that the Sun is stationary is "foolish and absurd in philosophy, and formally heretical since it explicitly contradicts in many places the sense of Holy Scripture..."; while the Earth's movement "receives the same judgement in philosophy and ... in regard to theological truth it is at least erroneous in faith."

At a meeting of the cardinals of the Inquisition on the following day, Pope Paul V instructed Bellarmine to deliver this result to Galileo, and to order him to abandon the Copernican opinions; should Galileo resist the decree, stronger action would be taken. On February 26 Galileo was called to Bellarmine's residence, and accepted the orders.¹⁵ On March 5, the decree was issued by the Congregation for the Index, prohibiting, condemning, or suspending various books which advocated the truth of the Copernican system.

Galileo met again with Bellarmine, apparently on friendly terms; and on March 11 he met with the Pope, who assured him that he was safe from persecution so long as he, the Pope, should live. Nonetheless, Galileo's friends Sagredo and Castelli reported that there were rumors that Galileo had been forced to recant and do penance. To protect his good name, Galileo requested a letter from Bellarmine stating the truth of the matter. This letter assumed great importance in 1633, as did the question whether Galileo had been ordered not to "hold or defend" Copernican ideas (which would have allowed their hypothetical treatment) or not to teach them in any way. If the Inquisition had issued the order not to teach heliocentrism at all, it would have been ignoring Bellarmine's position, which was in any case effectively ignored in the proceedings in 1633.^{citation needed}

In the end, the mission was a failure. Galileo did not persuade the Church to stay out of the controversy, but instead saw heliocentrism formally declared an idea that could not be held as truth, for lack of evidence. It was consequently termed heretical by the Qualifiers, since it contradicted the literal meaning of the Scriptures, though this position was not binding on the Church. Foscarini's book was banned; while Copernicus' De Revolutionibus, though not formally banned, was removed from circulation pending revisions, and in fact was not fully cleared until the 19th century. Though Galileo was personally safe, and his works had not been banned, there was now much doubt (felt by other astronomers as far away as Germany) whether it was possible to do serious work in Copernican astronomy.^{citation needed}

The Dialogue

In 1632 Galileo published his book, Dialogue Concerning the Two Chief World Systems, with formal authorization from the Inquisition for a book which presented a balanced view of both Copernican's and church's theories. However, in the book, the Copernican theory clearly receives better treatment, instead of a balanced view. Because of this, Galileo was ordered to appear before the Inquisition for trial.^{citation needed}

According to a controversial alternative theory, proposed by Pietro Redondi¹⁶ in 1983, the main reason for Galileo's condemnation in 1633 was his attack on the Aristotelian doctrine of matter rather than his defence of Copernicanism. An anonymous document discovered by Redondi in the Vatican archives had argued that the atomism espoused by Galileo in his previous work, The Assayer, of 1623 was incompatible with the doctrine of transubstantiation of the Eucharist.¹⁷ At the time, investigation of this complaint was apparently trusted to a Father Giovanni di Guevara, who was well-disposed towards Galileo, and who cleared The Assayer from any taint of unorthodoxy.¹⁸ However, according to Redondi:

• The Jesuits, who had been deeply offended by The Assayer, regarded the ideas about matter expressed by Galileo in The Dialogue as further evidence that his atomism was heretically inconsistent with the doctrine of the Eucharist, and strongly protested against it on these grounds.¹⁹
• Pope Urban VIII, who had been under attack by Spanish cardinals for being too tolerant of heretics, but who had also encouraged Galileo to publish The Dialogue, would have been severely compromised if his enemies among the Cardinal Inquisitors had found out that he had been guilty of supporting a publication containing Eucharistic heresies.
• Urban therefore took the very unusual step of establishing a commission to examine The Dialogue—ostensibly for the purpose of determining whether it would be possible to avoid referring the matter to the Inquisition at all, and as a special favour to Galileo's patron, the Grand Duke of Tuscany. Urban's real purpose, though, was to avoid having the accusations of Eucharistic heresy referred to the Inquisition, and he stacked the commission with friendly commissioners who could be relied upon not to mention them in their report.

Redondi's theory has been severely criticised, and almost universally rejected, by other Galileo scholars.²⁰

The Trial

Cristiano Banti's 1857 painting Galileo facing the Roman Inquisition

Galileo was ordered to Rome to stand trial on suspicion of heresy in 1633, "for holding as true the false doctrine taught by some that the sun is the center of the world", against the 1616 condemnation, since "it was decided at the Holy Congregation [...] on 25 Feb 1616 that [...] the Holy Office would give you an injunction to abandon this doctrine, not to teach it to others, not to defend it, and not to treat of it; and that if you did not acquiesce in this injunction, you should be imprisoned"²¹. The sentence of the Inquisition was in three essential parts:

• Galileo was found "vehemently suspect of heresy", namely of having held the opinions that the Sun lies motionless at the centre of the universe, that the Earth is not at its centre and moves, and that one may hold and defend an opinion as probable after it has been declared contrary to Holy Scripture. He was required to "abjure, curse, and detest" those opinions.²²
• He was ordered imprisoned; the sentence was later commuted to house arrest for the rest of his life.
• His offending Dialogue was banned; and in an action not announced at the trial, publication of any of his works was forbidden, including any he might write in the future²³

After a period with the friendly Archbishop Piccolomini in Siena, Galileo was allowed to return to his villa at Arcetri near Florence, where he spent the remainder of his life under house arrest with his friend and pupil Ferdinando II de' Medici, the Grand Duke of Tuscany. In 1638, he published a scientific book in Holland. His standing would remain questioned at every turn. In March 1641, Vincentio Reinieri, a follower and pupil of Galileo, wrote him at Arcetri that an Inquisitor had recently compelled the author of a book printed at Florence to change the words "most distinguished Galileo" to "Galileo, man of noted name."²⁴

However, partially in tribute to Galileo, at Arcetri the first academy devoted to the new experimental science, The Accademia del Cimento was formed, which is where Francesco Redi performed the first controlled experiment and many other important advancements were made which would eventually help usher in The Age of Enlightenment.

Modern church views

On February 15th, 1990, in a speech delivered at La Sapienza University in Rome,²⁵ Cardinal Ratzinger, now Pope Benedict XVI, cited some current views on the Galileo affair as forming what he called "a symptomatic case that illustrates the extent to which modernity’s doubts about itself have grown today in science and technology."²⁶ As evidence, he presented the views of a few prominent philosophers including Ernst Bloch and C.F. Von Weizsacker, as well as Paul Feyerabend, whom he quoted as saying:

"The Church at the time of Galileo kept much more closely to reason than did Galileo himself, and she took into consideration the ethical and social consequences of Galileo's teaching too. Her verdict against Galileo was rational and just, and the revision of this verdict can be justified only on the grounds of what is politically opportune."²⁷

Ratzinger did not indicate whether he agreed or disagreed with Feyerabend's assertions, but he did say "It would be foolish to construct an impulsive apologetic on the basis of such views".²⁶

In 1992, it was much lauded in the news that the Catholic Church had apparently "vindicated" Galileo.

Thanks to his intuition as a brilliant physicist and by relying on different arguments, Galileo, who practically invented the experimental method, understood why only the sun could function as the centre of the world, as it was then known, that is to say, as a planetary system. The error of the theologians of the time, when they maintained the centrality of the Earth, was to think that our understanding of the physical world's structure was, in some way, imposed by the literal sense of Sacred Scripture....

– Pope John Paul II, L'Osservatore Romano N. 44 (1264) - 4th November,1992

In 2000, Pope John Paul II issued a formal apology for all the errors of the Church over the last 2000 years including the trial of Galileo among others.²⁸²⁹

In January 2008, as Pope Benedict XVI, Ratzinger canceled a visit to La Sapienza University, the same one he had visited in 1990, following a protest letter signed by 67 of its 4,500 academics, as well as a few dozen of its 135,000 students. The petition included a truncated version of the Feyerabend quotation (omitting the first half) and asserted that Ratzinger's reiteration of the quoted words had "offended and humiliated" them.^{30 31} The full text of the speech that would have been given was made available a few days following Pope Benedict's cancelled appearance at the university.³² La Sapienza's rector, Renato Guarini, has been quoted as stating that the cancellation was a "defeat for the freedom of expression"; Italian Prime Minister Romano Prodi echoed such concerns.³³ Also notable were public counter-statements by La Sapienza professors Giorgio Israel³⁴ and Bruno Dalla Piccola.³⁰

Notes

References

• Artigas, Mariano; Martínez, Rafael and Shea, William R. (2005), New Light on the Galileo affair?. in McMullin (2005, pp.213–233)

• Beretta, Francesco (2005a), Galileo, Urban VIII, and the Prosecution of Natural Philosophers. in McMullin (2005, pp.234–261)

• Beretta, Francesco (2005b), The Documents of Galileo's Trial: Recent Hypotheses and Historical Criticisms. in McMullin (2005, pp.191–212)

• Baumgartner, Frederic J. (1989). "Galileo Heretic (Book Review)". The Sixteenth Century Journal XX (2): 309–10. 

• Drake, Stillman (1978), Galileo At Work. Chicago: University of Chicago Press. ISBN 0-226-16226-5

• Drake, Stillman (1990). Galileo: Pioneer Scientist. Chicago, MI: University of Toronto Press. ISBN 0-8020-2725-3. 

• Fantoli, Annibale (2005), The Disputed Injunction and its role in Galileo's Trial. in McMullin (2005, pp.117-149)

• Favaro, Antonio (1890–1909), ed.[1]. Le Opere di Galileo Galilei, Edizione Nazionale (Italian). (The Works of Galileo Galilei, National Edition, 20 vols.), Florence: Barbera, 1890–1909; reprinted 1929–1939 and 1964–1966. ISBN 88-09-20881-1. Searchable online copy from the Institute and Museum of the History of Science, Florence. Brief overview of "Le Opere" @ Finns Fine Books, [2] and here [3]

• Ferrone, Vincenzo; Firpo, Massimo (June, 1986). "From Inquisitors to Microhistorians: A Critique of Pietro Redondi's Galileo eretico". The Journal of Modern History 58 (2): 485–524. 

• Feyerabend, Paul (1995). Killing Time: The Autobiography of Paul Feyerabend. Chicago, MI: University of Chicago Press. ISBN 0-226-24531-4. 

• Finocchiaro, Maurice A. (1989), The Galileo Affair: A Documentary History. Berkeley: University of California Press. ISBN 0-520-06662-6

• Galilei, Galileo [1638,1914] (1954), Henry Crew and Alfonso de Salvio, translators, Dialogues Concerning Two New Sciences, Dover Publications Inc., New York, NY. ISBN 486-60099-8

• Gosselin, Edward A. (1985). "Galileo Eretico (Book Review)". The Sixteenth Century Journal XVI: 523–24. 

• Heilbron, John L. (2005). Censorship of Astronomy in Italy after Galileo. In McMullin (2005, pp.279–322). 

• McMullen, Emerson Thomas, Galileo's condemnation: The real and complex story (Georgia Journal of Science, vol.61(2) 2003)

• McMullin, Ernan ed.(2005), The Church and Galileo, University of Notre Dame Press, Notre Dame, IN. ISBN 0-268-03483-4

• McMullin, Ernan (2005b), The Church's Ban on Copernicanism, 1616. in McMullin (2005, pp.150-190)

• Pagano, Sergio M. (ed); (in collaboration with Luciano, Antonio G.) (1984). "I Documenti del Processo di Galileo Galilei". Pontificiae Academiae Scientiarum Scripta Varia, no.53, Vatican City. Retrieved on 2005-07-22. ISBN 88-85042-11-2

• Ratzinger, Joseph Cardinal (1994). Turning point for Europe? The Church in the Modern World—Assessment and Forecast. translated from the 1991 German edition by Brian McNeil. San Francisco, CA: Ignatius Press. ISBN 0-89870-461-8. OCLC 60292876. 

• Redondi, Pietro (1983), Galileo eretico, Einaudi, Turin; Galileo: Heretic (transl: Raymond Rosenthal) Princeton University Press, 1987 (reprint 1989 ISBN 0-691-02426-X); Penguin, 1988 (reprint 1990 ISBN 0-14-012541-8)

• Speller, Jules, Galileo's Inquisition Trial Revisited , Peter Lang Europäischer Verlag, Frankfurt am Main, Berlin, Bern, Bruxelles, New York, Oxford, Wien, 2008. 431 pp. ISBN 978-3-631-56229-1 / US-ISBN 978-0-8204-8798-4

• Sharratt, Michael (1996), Galileo: Decisive Innovator. Cambridge University Press, Cambridge. ISBN 0-521-56671-1

• Wallace, William A. (1991). Galileo, the Jesuits and the Medieval Aristotle. Great Yarmouth: Variorum. ISBN 0-86078-297-2. 

• Westfall, Richard S. (1987). "Galileo Heretic (Book Review)". Science 237: 1059–60. 

• Westfall, Richard S. (1989). Essays on the Trial of Galileo. Vatican City: Vatican Observatory. 

External links

• The Starry Messenger (1610). An English translation from Bard College
• Sidereus Nuncius (1610) (Latin) Original Latin text at LiberLiber online library.
• Galileo's letter to Castelli of 1613. The English translation given on the web page at this link is from Finocchiaro (1989), contrary to the claim made in the citation given on the page itself.
• Galileo's letter to the Grand Duchess Christina of 1615
• Bellarmine's letter to Foscarini of 1615
• Inquisition documents, 1616 and 1633
• Galileo: Science and Religion Extensively documented series of lectures by William E.Carroll and Peter Hodgson.
• Edizione Nationale (Italian). A searchable online copy of Favaro's National Edition of Galileo's works at the website of the Institute and Museum of the History of Science, Florence.