In 1610, Galileo published his Sidereus Nuncius (Starry Messenger), describing the surprising observations that he had made with the new telescope, namely the phases of Venus and the Galilean moons of Jupiter. He went on to propose a theory of tides in 1616, and of comets in 1619. He argued that the tides were evidence for the motion of the Earth, and promoted the heliocentric theory of Nicolaus Copernicus (published in De revolutionibus orbium coelestium in 1543).
Following mounting controversy over theology, astronomy and philosophy, the Roman Inquisition tried Galileo in 1633 and found him "gravely suspect of heresy," sentencing him to indefinite imprisonment. This was subsequently commuted to house arrest, under which he remained for the rest of his life.
1600s revolution in cosmology 
Galileo began his telescopic observations in the later part of 1609, and by March 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 to be very cloudy masses in the sky (nebulae) into collections of stars too faint to see individually without a telescope. Other observations followed, including the phases of Venus and the existence of sunspots.
None of these findings, which were difficult at first for other astronomers to verify, proved that the Earth moved, or directly contradicted either Aristotle's model or Christian doctrine. However, they caused difficulties for natural philosophers of the time, as they contradicted scientific and philosophical ideas based on those of Aristotle and Ptolemy and closely associated with the Catholic Church then (despite their being pagan authors). In particular, the phases of Venus, which showed it to circle the sun, and the observation of moons orbiting Jupiter contradicted the geocentric model of Ptolemy, in which the motion of all celestial bodies was centered on the Earth.
Jesuit astronomers, experts both in Church teachings, science, 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 1610, Galileo complained that some of the philosophers who opposed his discoveries had refused even to look through a telescope:
My dear Kepler, I wish that we might laugh at the remarkable stupidity of the common herd. What do you have to say about the principal philosophers of this academy who are filled with the stubbornness of an asp and do not want to look at either the planets, the moon or the telescope, even though I have freely and deliberately offered them the opportunity a thousand times? Truly, just as the asp stops its ears, so do these philosophers shut their eyes to the light of truth."
Geocentrists who did verify and accept Galileo's findings had an alternative to Ptolemy's model in an alternative geocentric (or "geo-heliocentric") model proposed some decades earlier by Tycho Brahe—a model, in which, for example, Venus circled the sun.
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. Neither of them, however, was the first to recognise sunspots—the Chinese had already been familiar with them for centuries.
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," was plotting to cause him trouble over the motion of the earth, or anything else that would serve the purpose. 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.
Bible argument 
In the Catholic world prior to Galileo's conflict with the Church, the majority of educated people subscribed to the Aristotelian geocentric view that the earth was the center of the universe and that all heavenly bodies revolved around the Earth. Despite the use of Copernican theories to reform the calendar in 1582, this agreed with a literal interpretation of Scripture in several places, such as , , , , (in contrast with ). Heliocentrism, the theory that the Earth was a planet, which along with all the others 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, poet and specialist in Greek literature, Cosimo Boscaglia. In conversation with Galileo's patron Cosimo II de' Medici and Cosimo's mother Christina of Lorraine, Boscaglia said that the telescopic discoveries were valid, but that the motion of the Earth was obviously contrary to Scripture:
"Dr. Boscaglia had talked to Madame [Christina] for a while, and though he conceded all the things you have discovered in the sky, he said that the motion of the earth was incredible and could not be, particularly since Holy Scripture obviously was contrary to such motion."
Galileo was defended on the spot by his former student Benedetto Castelli, now a professor of mathematics and Benedictine abbot. The exchange reported to Galileo by Castelli, Galileo decided 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. Later, in 1615, he expanded this into his much longer Letter to the Grand Duchess Christina.
In late 1614 or early 1615, one of Caccini's fellow Dominicans, Niccolò Lorini, acquired a copy of Galileo's letter to Castelli. Lorini and other Dominicans at the Convent of San Marco considered the letter of doubtful orthodoxy, in part because it may have violated the decrees of the Council of Trent:
"...to check unbridled spirits, [the Holy Council] decrees that no one relying on his own judgement shall, in matters of faith and morals pertaining to the edification of Christian doctrine, distorting the Scriptures in accordance with his own conceptions, presume to interpret them contrary to that sense which the holy mother Church... has held or holds..." - Decree of the Council of Trent (1545-1563). Quoted in Langford, 1992.
Lorini and his colleagues decided to bring Galileo's letter to the attention of the Inquisition. In February 1615 Lorini accordingly sent a copy to the Secretary of the Inquisition, Cardinal Paolo Emilio Sfondrati, with a covering letter critical of Galileo's supporters:
"All our Fathers of the devout Convent of St. Mark feel that the letter contains many statements which seem presumptuous or suspect, as when it states that the words of Holy Scripture do not mean what they say; that in discussions about natural phenomena the authority of Scripture should rank last... [the followers of Galileo] were taking it upon themselves to expound the Holy Scripture according to their private lights and in a manner different from the common interpretation of the Fathers of the Church..." - Letter from Lorini to Cardinal Sfrondato, Inquisitor in Rome, 1615. Quoted in Langford, 1992.
Galileo soon heard reports that Lorini had obtained a copy of his letter to Castelli and was 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. 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.
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 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 attempted to reconcile Copernicus with the biblical passages that seemed to be in contradiction. Bellarmine at first expressed the opinion that Copernicus's book would not be banned, but would at most require some editing so as to present the theory purely as a calculating device for "saving the appearances" (i.e. preserving the observable evidence)
Foscarini sent a copy of his book to Bellarmine, who replied in a letter of April 12, 1615. Galileo is mentioned by name in the letter, and a copy was soon sent to him. After some preliminary salutations and acknowledgements, Bellarmine begins by telling Foscarini that it is prudent for him and Galileo to limit themselves to treating heliocentrism as a merely hypothetical phenomenon and not a physically real one. Further on he says that interpreting heliocentrism as physically real would be "a very dangerous thing, likely not only to irritate all scholastic philosophers and theologians, but also to harm the Holy Faith by rendering Holy Scripture as false." Moreover, while the topic was not inherently a matter of faith, the statements about it in Scripture were so by virtue of who said them—namely, the Holy Spirit. He conceded that if there were conclusive proof, "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." However, demonstrating that heliocentrism merely "saved the appearances" could not be regarded as sufficient to establish that it was physically real. Although he believed that the former may well have been possible, he had "very great doubts" that the latter would be, and in case of doubt it was not permissible to depart from the traditional interpretation of Scriptures. His final argument was a rebuttal of an analogy that Foscarini had made between a moving Earth and a ship on which the passengers perceive themselves as apparently stationary and the receding shore as apparently moving. Bellarmine replied that in the case of the ship the passengers know that their perceptions are erroneous and can mentally correct them, whereas the scientist on the Earth clearly experiences that it is stationary and therefore the perception that the Sun, moon and stars are moving is not in error and does not need to be corrected.
Bellarmine found no problem with heliocentrism so long as it was treated as a purely hypothetical calculating device and not as a physically real phenomenon, but he did not regard it as permissible to advocate the latter unless it could be conclusively proved through current scientific standards. This put Galileo in a difficult position, because he believed that the available evidence strongly favoured heliocentrism, and he wished to be able to publish his arguments.
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. 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, 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, that the actual referral may have been precipitated by Galileo's aggressive campaign to prevent the condemnation of Copernicanism.
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 ordered,
"to abstain completely from teaching or defending this doctrine and opinion or from discussing it... to abandon completely... the opinion that the sun stands still at the center of the world and the earth moves, and henceforth not to hold, teach, or defend it in any way whatever, either orally or in writing." -The Inquisition's injunction against Galileo, 1616.
With no attractive alternatives, Galileo accepted the orders delivered, even sterner than those recommended by the Pope. 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.
In the end, Galileo did not persuade the Church to stay out of the controversy, but instead saw heliocentrism formally declared false. 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.
Copernican books banned 
Following the Inquisition's injunction against Galileo, the papal Master of the Sacred Palace ordered that Foscarini's Letter be banned, and Copernicus' De revolutionibus suspended until corrected. The papal Congregation of the Index preferred a stricter prohibition, and so with the Pope's approval, on March 5 the Congregation banned all books advocating the Copernican system, which it called "the false Pythagorean doctrine, altogether contrary to Holy Scripture."
Francesco Ingoli, a consultor to the Holy Office, recommended that De revolutionibus be amended rather than banned due to its utility for calendrics. In 1618 the Congregation of the Index accepted his recommendation, and published their decision two years later, allowing a corrected version of Copernicus' book to be used. The uncorrected De revolutionibus remained on the Index of banned books until 1758.
Galileo was personally safe and his works had not been banned, but there was doubt (felt by other astronomers as far away as Germany) whether it was possible to do serious work in Copernican astronomy.
Galileo's Dialogue, which was published in 1632 to great popularity, was an account of conversations between a Copernican scientist, Salviati, an impartial and witty scholar named Sagredo, and a ponderous Aristotelian named Simplicio, who employed stock arguments in support of geocentricity, and was depicted in the book as being an intellectually inept fool. Simplicio's arguments are systematically refuted and ridiculed by the other two characters with what Youngson calls "unassailable proof" for the Copernican theory (at least versus the theory of Ptolemy—as Finocchiaro points out, "the Copernican and Tychonic systems were observationally equivalent and the available evidence could be explained equally well by either"), which reduces Simplicio to baffled rage, and makes the author's position unambiguous. Indeed, although Galileo states in the preface of his book that the character is named after a famous Aristotelian philosopher (Simplicius in Latin, Simplicio in Italian), the name "Simplicio" in Italian also had the connotation of "simpleton." Although authors Langford and Stillman Drake assert that Simplicio was modeled on philosophers Lodovico delle Colombe and Cesare Cremonini, Pope Urban's demand for his own arguments to be included in the book resulted in Galileo putting them in the mouth of Simplicio. Some months after the book's publication, Pope Urban VIII banned its sale and had its text submitted for examination by a special commission.
With the loss of many of his defenders in Rome because of Dialogue Concerning the Two Chief World Systems, Galileo was ordered 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". A panel of theologians, consisting of Melchior Inchofer, Agostino Oreggi and Zaccaria Pasqualigo, reported on the Dialogue. Their opinions were strongly argued in favour of the view that the Dialogue taught the Copernican theory.
Galileo was found guilty, and the sentence of the Inquisition, issued on 22 June 1633, 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 center 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.
- He was sentenced to formal imprisonment at the pleasure of the Inquisition. On the following day this was commuted to house arrest, which he remained under 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 future.
According to popular legend, after his abjuration Galileo allegedly muttered the rebellious phrase "and yet it moves" (Eppur si muove), but there is no evidence that he actually said this or anything similar. The first account of the legend dates to a century after his death. The phrase "Eppur si muove" does appear, however, in a painting of the 1640s by the Spanish painter Bartolomé Esteban Murillo or an artist of his school. The painting depicts an imprisoned Galileo apparently pointing to a copy of the phrase written on the wall of his dungeon 
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. He continued his work on mechanics, and 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."
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 controlled experiments and many other important advancements were made which would eventually help usher in The Age of Enlightenment.
Despite the fact that the decision of attributing the Pope's words to Simplicio was perceived as a mockery, some historians suggest that Galileo might have not acted out of malice.
Dava Sobel argues that during this time, Urban had fallen under the influence of court intrigue and problems of state. His friendship with Galileo began to take second place to his feelings of persecution and fear for his own life. The problem of Galileo was presented to the pope by court insiders and enemies of Galileo, following claims by a Spanish cardinal that Urban was a poor defender of the church. This situation did not bode well for Galileo's defense of his book.
In his 1998 book, Scientific Blunders, Robert Youngson indicates that Galileo struggled for two years against the ecclesiastical censor to publish a book promoting heliocentrism. He claims the book passed only as a result of possible idleness or carelessness on the part of the censor, who was eventually dismissed. On the other hand, Jerome K. Langford and Raymond J. Seeger contend that Pope Urban and the Inquisition gave formal permission to publish the book, Dialogue Concerning the Two Chief World Systems, Ptolemaic & Copernican. They claim Urban personally asked Galileo to give arguments for and against heliocentrism in the book, to include Urban's own arguments, and for Galileo not to advocate heliocentrism.
Redondi's theory 
According to a controversial alternative theory proposed by Pietro Redondi 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. 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. 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.
- 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, after banning the book's sale, established 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 favor 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. The commission reported against Galileo.
Modern Catholic Church views 
In 1758 the Catholic Church dropped the general prohibition of books advocating heliocentrism from the Index of Forbidden Books. It did not, however, explicitly rescind the decisions issued by the Inquisition in its judgement of 1633 against Galileo, or lift the prohibition of uncensored versions of Copernicus's De Revolutionibus or Galileo's Dialogue. The issue finally came to a head in 1820 when the Master of the Sacred Palace (the Church's chief censor), Filippo Anfossi, refused to license a book by a Catholic canon, Giuseppe Settele, because it openly treated heliocentrism as a physical fact. Settele appealed to the then pope, Pius VII. After the matter had been reconsidered by the Congregation of the Index and the Holy Office, Anfossi's decision was overturned. Copernicus's De Revolutionibus and Galileo's Dialogue were then subsequently omitted from the next edition of the Index when it appeared in 1835.
On February 15, 1990, in a speech delivered at La Sapienza University in Rome, Cardinal Ratzinger, the future 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." As evidence, he presented the views of a few prominent philosophers including Ernst Bloch and Carl Friedrich von Weizsäcker, 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.
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."
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) - November 4, 1992
In 2000, Pope John Paul II issued a formal apology for all the mistakes committed by some Catholics in the last 2,000 years of the Catholic Church's history, including the trial of Galileo among others.
In January 2008, Pope Benedict XVI 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 and asserted that Ratzinger's reiteration of the quoted words had "offended and humiliated" them. 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. La Sapienza's rector, Renato Guarini, has been quoted as stating that the cancellation was a "defeat for the freedom of expression"; former Italian Prime Minister Romano Prodi echoed such concerns. Also notable were public counter-statements by La Sapienza professors Giorgio Israel and Bruno Dalla Piccola.
Artistic treatments 
See also 
- Nicolaus Copernicus
- Giordano Bruno
- Catholic Church and science
- "And yet it moves", words supposedly uttered by Galileo after the incident
- Stillman Drake
- Finocchiaro (1989, p.1); Blackwell (1991, p.2). Blackwell (1991, p.50) dates the start of the Galileo affair to 1610. Finocchiaro (1989, p.1) puts it a few years later, in 1613.
- Drake (1978, p.162), Sharratt (1994, p.86), Favaro (1900, 10:421-423) (Latin).
- Galileo did not name the philosophers concerned, but Galileo scholars have identified two of them as Cesare Cremonini and Giulio Libri (Drake, 1978, pp.162, 165; Sharratt, 1994, p.87). Claims of similar refusals by bishops and cardinals have sometimes been made, but there appears to be no evidence to support them.
- Favaro,(1900, 10:423) (Latin). The original Latin reads: "Volo, mi Keplere, ut rideamus insignem vulgi stultitiam. Quid dices de primariis huius Gimnasii philosophis, qui, aspidis pertinacia repleti, nunquam, licet me ultro dedita opera millies offerente, nec Planetas, nec , nec perspicillum, videre voluerunt? Verum ut ille aures, sic isti oculos, contra veritatis lucem obturarunt." A variety of translations of variable quality have appeared in print—Bethune (1830, p.29), Fahie (2005, p.102), Lodge (2003, p.106), and de Santillana (1976, p.9), for example.
- Sharratt (1994, p.98).
- "La legha del Pippione" (Favaro, 1901, 11:476) (Italian). "The Pigeon" ("il Pippione") was Cigoli's derisive nickname for the presumed leader of the group, Lodovico delle Colombe (Sharratt, 1994, p.95; Favaro, 1901, 11:176, 11:228–29, 11:502). It is a pun on Colombe's surname, which is the feminine plural form of the Italian word for "Dove." "Pippione" is a now obsolete Italian word with a triple entendre—besides meaning "young pigeon," it was also a jocular colloquialism for a testicle, and a Tuscan dialect word for a fool.
- Drake (1978, p.180), Favaro (1901) 11:241–42) (Italian).
- Blackwell, Richard (1991). Galileo, Bellarmine, and the Bible. Notre Dame: University of Notre Dame Press. p. 25. ISBN 0268010242.
- "The Gregorian calendar, first adopted in 1582, was in fact based on computations that made use of Copernicus' work." Thomas Kuhn (1957). The Copernican Revolution. Harvard University Press. p. 125.
- Four Treatises for the Reconsideration of the History of Science, Fabio J. a. Farina
- Heilbron (2010), p.369
- Drake, Jerome J. Langford ; foreword by Stillman (1992). Galileo, science, and the church (3rd ed. ed.). Ann Arbor: University of Michigan Press. p. 54. ISBN 0472065106. -Letter from Benedetto Castelli to Galileo, 1613-14
- Sharratt (1994, p.109).
- Sharratt (1994, pp.112–26).
- Langford (1992), p.56-57
- Drake (1978, p.240), Sharratt (1994, pp.110−111), Favaro (1907, 19:297−298) (Italian).
- Langford (1992), p.56-57
- Sharratt (1994, p.111), Favaro (1907, 19:307−311) (Latin)(Italian).
- Drake (1978, p.241), Favaro (1895, 5:291−292) (Italian).
- Langford, 1992, p.79
- Blackwell (1991, p.74), Sharratt (1994, p.112) "Saving the appearances" meant that the theory could enable astronomers to accurately predict and explain all the empirically observed apparent motions of the Sun, Moon, stars and planets.
- Blackwell (1991, p.265–67), Finocchiaro (1989, p.67–9). A copy of Finocchiaro's translation of the letter is available on-line.
- Sharratt (1994, p.115-25).
- Fantoli (2005, p.118), McMullin (2005b, p.152), Favaro(1907, 19:320) (Italian).
- Beretta (2005a, pp.247-248), Favaro(1907, 19:318) (Italian).
- McMullin (2005b, pp.167-168), Drake (1978, p.252), Sharratt (1994, p.127), Favaro (1902,12:242) (Italian).
- An inaccuracy in Guicciardini's letter has led some historians (e.g. Drake, 1978, p.252; Sharratt, 1994, p.127) to identify a meeting between Cardinal Orsini and the Pope as the specific incident which triggered the Copernican propositions' referral to the qualifiers. This cannot have been the case, however, because the meeting did not occur until several days after the propositions had been referred to them. (McMullin, 2005b, pp.152, 153)
- Heilbron (2010), p.218
- Drake (1978, p.253).
- Finnochiario (2007), p.154
- Youngson, Robert M. Scientific Blunders: A Brief History of How Wrong Scientists Can Sometimes Be; Carroll & Graff Publishers, Inc.; 1998; Pages 290-293
- Finocchiaro (1997), p.54)
- Finocchiaro (1997), p.82); Moss & Wallace (2003), p.11)
- Finocchiaro (1989, p.288). A copy of this quotation, taken from Finocchiaro's translation of the Inquisition's judgement against Galileo is available online
- Sharratt (1994, pp.172–3]).
- "Papal Condemnation (Sentence) of Galileo in 1633". University of Missouri—Kansas City. Retrieved 21 June 2011.
- Fantoli (2005, p.139), Finocchiaro (1989, p.288–293). Finocchiaro's translation of the Inquisition's judgment against Galileo is available online. "Vehemently suspect of heresy" was a technical term of canon law and did not necessarily imply that the Inquisition considered the opinions giving rise to the verdict to be heretical. The same verdict would have been possible even if the opinions had been subject only to the less serious censure of "erroneous in faith" (Fantoli, 2005, p.140; Heilbron, 2005, pp.282-284).
- Finocchiaro (1989, pp.38, 291, 306). Finocchiaro's translation of the Inquisition's judgement against Galileo is available on-line.
- Drake (1978, p.367), Sharratt (1994, p.184), Favaro (1905, 16:209, 230)(Italian). When Fulgenzio Micanzio, one of Galileo's friends in Venice, sought to have Galileo's Discourse on Floating Bodies reprinted in 1635, he was informed by the Venetian Inquisitor that the Inquisition had forbidden further publication of any of Galileo's works (Favaro, 1905, 16:209)(Italian), and was later shown a copy of the order (Favaro,1905, 16:230).(Italian) When the Dutch publishers Elzevir published Galileo's Dialogues Concerning Two New Sciences in 1638, some five years after his trial, they did so under the pretense that a manuscript he had presented to the French Ambassador to Rome for preservation and circulation to interested intellectuals had been used without his knowledge (Sharratt, 1994, p.184; Galilei, 1954 p.xvii; Favaro, 1898, 8:43 (Italian)). Return to other article: Galileo Galilei; Dialogue; Two New Sciences.
- Drake (1978, p. 356)
- (Drake, 1978, p. 357).
- Drake (1978, p.414).
- See Langford (1966, pp.133–134), and Seeger (1966, p.30), for example. Drake (1978, p.355) asserts that Simplicio's character is modelled on the Aristotelian philosophers, Lodovico delle Colombe and Cesare Cremonini, rather than Urban. He also considers that the demand for Galileo to include the Pope's argument in the Dialogue left him with no option but to put it in the mouth of Simplicio (Drake, 1953, p.491). Even Arthur Koestler, who is generally quite harsh on Galileo in The Sleepwalkers (1959), after noting that Urban suspected Galileo of having intended Simplicio to be a caricature of him, says "this of course is untrue" (1959, p.483)
- Sobel, Dava (2000, pp.223-225) . Galileo's Daughter. London: Fourth Estate. ISBN 1-85702-712-4.
- Redondi (1983).
- Redondi (1983) attributed authorship of this document to Orazio Grassi, the target of savage attacks by Galileo in The Assayer. However, this attribution has been declared to be absolutely unsupportable by a handwriting expert who compared its handwriting with that of contemporaneous documents known to have been written by Grassi (Pagano, 1984, p.44).
- Wallace (1991, pp.VII 81–83).
- Redondi acknowledges that there are no surviving documents in which these protests were made explicit. His conclusions are based on complex inferences from indirect evidence.
- Ferrone and Firpo (1986) and Westfall (1989, pp.58–93) provide comprehensive overviews of some of the criticisms that have been levelled at Redondi's theory. Briefer criticisms can be found in Pagano (1984, pp.43–48), Gosselin (1985), Westfall (1987), Baumgartner (1989), Drake (1990, p.179—footnote), Blackwell (1991, pp.154–155, footnote 47), Wallace (1991, pp.VII pp.67, 81–84), Sharratt (1994, p.149), Artigas et al. (2005, pp.214, 222, 225–227), and Beretta (2005b, pp.192, 202–203).
- White (2007)
- Heilbron (2005, p.307).
- Heilbron (2005, pp.279, 312–313)
- An earlier version had been delivered on December 16, 1989, in Rieti, and a later version in Madrid on February 24, 1990 (Ratzinger, 1994, p.81). According to Feyerabend himself, Ratzinger had also mentioned him "in support of" his own views in a speech in Parma around the same time (Feyerabend, 1995, p.178).
- Ratzinger (1994, p.98).
- Ratzinger (1994, p.98). A partly browsable on-line copy of Ratzinger's text is available at Amazon.com. The page containing the quotation can be obtained by searching on a short extract. An alternative translation (Allen, 2008) is also available on the web. However, Allen's attribution of his translation to a speech supposedly given by Ratzinger in Parma on March 15, 1990 contradicts the attribution given by his source—namely, Ratzinger's speech at La Sapienza on February 15.
- Daniel N. Robinson citing John Paul II in Human nature in its wholeness: a Roman Catholic perspective edited by D. N. Robinson, G. M. Sweeney and R. Gill, Front Cover
- Galileo had tried to emphasize that science describes the physical world and how it works, while the Bible describes the spiritual world and how we should live. As such, many believe the Bible contains many metaphorical or symbolic passages, and is not always literal. The seeming resolution of this conflict, as well as the conflict itself, has made a lasting impact in the world and become an important part of history.Pope says sorry for sins of church | World news | The Guardian
- Online NewsHour: A Papal Apology, March 13, 2000
- "Sapienza Academics Reject Pope’s University Address". Corriere della Sera (English edition). 2008-01-15.
- "Papal visit scuppered by scholars". BBC News. 2008-01-15.
- "The speech Pope Benedict did not deliver". Catholic World News. 2008-01-19.
- Fisher, Ian (2008-01-16). "Pope cancels speech at university in Rome". Boston Globe.
- "Rejection of Pope's speech is fear of dialogue between faith and reason, professor says". Catholic News Agency. 2008-01-15.; "WHEN RATZINGER DEFENDED GALILEO AT "LA SAPIENZA"". This last citation is a reprint of the original article that appeared in L'Osservatore Romano on January 15, 2008. Scroll down for access.
- Artigas, Mariano; Martínez, Rafael; Shea, William R. (2005). "New Light on the Galileo affair?". In McMullin, Ernan. The Church and Galileo. University of Notre Dame Press, Notre Dame. pp. 213–233. ISBN 0-268-03483-4.
- Beretta, Franchesco (2005). "Galileo, Urban VIII, and the Prosecution of Natural Philosophers". In McMullin, Ernan. The Church and Galileo. University of Notre Dame Press, Notre Dame. p. 234–261. ISBN 0-268-03483-4.
- Beretta, Franchesco (2005). "The Documents of Galileo's Trial: Recent Hypotheses and Historical Criticisms". In McMullin, Ernan. The Church and Galileo. University of Notre Dame Press, Notre Dame. p. 191–212. ISBN 0-268-03483-4.
- Baumgartner, Frederic J. (1989). "Galileo Heretic (Book Review)". The Sixteenth Century Journal XX (2): 309–10.
- Bowler, Peter J.; Morus, Iwan Rhys (2005). Making modern science: a historical survey. Chicago IL: University of Chicago Press. ISBN 0-226-06860-9.
- Bethune, John Elliot Drinkwater (1830). The life of Galileo Galilei, with illustrations of the advancement of experimental philosophy. London.
- Blackwell, Richard J. (1991). Galileo, Bellarmine, and the Bible. Notre Dame, IN: University of Notre Dame Press. ISBN 0-268-01024-2.
- 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, Ernan. The Church and Galileo. University of Notre Dame Press, Notre Dame. pp. 117–149. ISBN 0-268-03483-4.
- Favaro, Antonio, ed. (1890–1909; reprinted 1929–1939 and 1964–1966). Le Opere di Galileo Galilei, Edizione Nazionale [The Works of Galileo Galilei, National Edition] (in italian). Florence: Barbera. ISBN 88-09-20881-1. A searchable online copy is available on the Institute and Museum of the History of Science, Florence, and a brief overview of Le Opere is available at Finn's fine books, and here.
- 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. doi:10.1086/243016.
- 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, CA: University of California Press. ISBN 0-520-06662-6.
- Galileo Galilei (1953). Dialogue Concerning the Two Chief World Systems. Translator: Stillman Drake. Berkeley, CA: University of California Press. ISBN 0-520-00449-3.
- Galileo Galilei; Finocchiaro, Maurice A. (1997). Galileo on the World Systems: A New Abridged Translation and Guide. Berkeley, CA: University of California Press. ISBN 0-520-20548-0.
- Galileo Galilei (1954) [1638,1914]. Dialogues Concerning Two New Sciences. Translators: G Henry Crew and Alfonso de Salvio. New York, NY.: Dover Publications Inc. ISBN 86-60099-8 Check
- 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, Ernan. The Church and Galileo. University of Notre Dame Press, Notre Dame. ISBN 0-268-03483-4.
- Koestler, Arthur (1990) . The Sleepwalkers: A History of Man's Changing Vision of the Universe. Penguin. ISBN 0-14-019246-8. Original edition published by Hutchinson (1959, London).
- Langford, Jerome K., O.P. (1998) . Galileo, Science and the Church (third ed.). St. Augustine's Press. ISBN 1-890318-25-6.. Original edition by Desclee (New York, NY, 1966)
- 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. ISBN 0-268-03483-4. Reference-McMullin-2005.
- McMullin, Ernan (2005). "The Church's Ban on Copernicanism, 1616". In McMullin, Ernan. The Church and Galileo. University of Notre Dame Press, Notre Dame. pp. 150–190. ISBN 0-268-03483-4.
- Moss, Jean Dietz; Wallace, William (2003). Rhetoric & dialectic in the time of Galileo. Washington D.C.: CUA Press. ISBN 0-8132-1331-2.
- 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 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 (1987—English translation) . Galileo Heretic. Translator: Raymond Rosenthal. Princeton, NJ: Princeton University Press. ISBN 0-691-08451-3.
- de Santillana, Giorgio (1976—Midway reprint) . The Crime of Galileo. Chicago, Ill: University of Chicago Press. ISBN 0-226-73481-1.
- Seeger, Raymond J. (1966). Galileo Galilei, his life and his works. Oxford: Pergamon Press.
- 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 (1994). Galileo: Decisive Innovator. Cambridge: Cambridge University Press. 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 (4818): 1059–60. Bibcode:1987Sci...237.1059W. doi:10.1126/science.237.4818.1059. PMID 17837398.
- Westfall, Richard S. (1989). Essays on the Trial of Galileo. Vatican City: Vatican Observatory.
- Galileo Galilei, Scriptural Exegete, and the Church of Rome, Advocate of Science lecture (audio here) by Thomas Aquinas College tutor Dr. Christopher Decaen
- "The End of the Myth of Galileo Galilei" by Atila Sinke Guimarães
- 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.