{{Short description|17th-century conflict between Galileo Galilei and the Roman Catholic Church}} {{pp-sock|expiry=15:46, 27 April 2017|small=yes}} {{use mdy dates|date=October 2024}} [[File:Galileo before the Holy Office - Joseph-Nicolas Robert-Fleury, 1847.png|upright=1.35|thumb|''Galileo before the Holy Office'', a 19th-century painting by [[Joseph-Nicolas Robert-Fleury]]]] The '''Galileo affair''' was an early 17th century political, religious, and scientific controversy regarding the astronomer [[Galileo Galilei]]'s defence of [[heliocentrism]], the idea that the [[Earth]] revolves around the [[Sun]]. It pitted supporters and opponents of Galileo within both the [[Catholic Church]] and academia against each other through two phases: an interrogation and condemnation of Galileo's ideas by a panel of the [[Roman Inquisition]] in 1616, and a second trial in 1632 which led to Galileo's [[house arrest]] and a ban on his books.Blackwell ([[#Reference-Blackwell-1991|1991]], p. 2). Blackwell ([[#Reference-Blackwell-1991|1991]], p. 50) dates the start of the Galileo affair to 1610. Finocchiaro ([[#Reference-Finocchiaro-1989|1989]], [https://books.google.com/books?id=wKCZFJuMCaQC&pg=PA1 p. 1]) puts it a few years later, in 1613. In 1610, Galileo published his ''[[Sidereus Nuncius]]'' (''Starry Messenger'') describing the observations that he had made with his new, much stronger [[telescope]], amongst them the [[Galilean moons]] of [[Jupiter]]. With these observations and additional observations that followed, such as the [[phases of Venus]], he promoted the heliocentric theory of [[Nicolaus Copernicus]] published in ''[[De revolutionibus orbium coelestium]]'' in 1543. Galileo's opinions were met with opposition within the Catholic Church, and in 1616 the Inquisition declared heliocentrism to be both scientifically indefensible and heretical. Galileo went on to propose a theory of [[Discourse on the Tides|tides]] in 1616, and of [[Discourse on Comets|comets]] in 1619; he argued (incorrectly) that the tides were evidence for the motion of the Earth. In 1632, Galileo published his ''[[Dialogue Concerning the Two Chief World Systems]]'', which defended heliocentrism while describing geocentrists as "simpletons". Responding to mounting controversy, the Roman Inquisition tried Galileo in 1633 and found him "vehemently suspect of [[heresy]]", sentencing him to house arrest. At this point, heliocentric books were banned and Galileo was ordered to abstain from holding, teaching or defending heliocentric ideas after the trial. The affair was complex, with Pope [[Urban VIII]] originally being a patron and supporter of Galileo before turning against him. Urban initially gave Galileo permission to publish on the Copernican theory so long as he treated it as a hypothesis, but after the publication of the ''Dialogue'' in 1632, the patronage was broken off.{{cite web |title=Pope Urban VIII (Maffeo Barberini) (1568–1644) |url=http://galileo.rice.edu/gal/urban.html |website=The Galileo Project |publisher=Rice University |quote=Upon Barberini's ascendance of the papal throne, in 1623, Galileo came to Rome and had six interviews with the new Pope. It was at these meetings that Galileo was given permission to write about the Copernican theory, as long as he treated it as a hypothesis. After the publication of Galileo' s Dialogue Concerning the Two Chief Systems of the World, in 1632, the patronage relationship was broken. It appears that the Pope never forgave Galileo for putting the argument of God's omnipotence (the argument he himself had put to Galileo in 1623) in the mouth of Simplicio, the staunch Aristotelian whose arguments had been systematically destroyed in the previous 400-odd pages. At any rate, the Pope resisted all efforts to have Galileo pardoned. }} Historians of science have since corrected numerous false interpretations of the affair.{{cite book|last1=Finocchiaro|first1=Maurice A.|title=The Trial of Galileo : Essential Documents|date=2014|isbn=978-1-62466-132-7|chapter=Introduction|pages=1–4|publisher=Hackett Publishing Company, Incorporated |quote=..one of the most common myths widely held about the trial of Galileo, including several elements: that he "saw" the earth's motion (an observation still impossible to make even in the twenty-first century); that he was "imprisoned" by the Inquisition (whereas he was actually held under house arrest); and that his crime was to have discovered the truth. And since to condemn someone for this reason can result only from ignorance, prejudice, and narrow-mindedness, this is also the myth that alleges the incompatibility between science and religion.}}[[#Reference-McMullin-2008|McMullin (2008)]] == Initial controversies == [[File:Jupiter family.jpg|thumb|250px|Photomontage of the [[Galilean moons]]. Galileo viewed these moons as a smaller Copernican system within the Solar System and used them to support [[heliocentrism]].]] {{multiple image |footer=In 1610 [[Galileo Galilei]] observed with his telescope that [[Phases of Venus|Venus showed phases]], despite remaining near the Sun in Earth's sky (first image). This proved that it orbits the [[Sun]] and not [[Earth]], as predicted by [[Copernicus]]'s [[heliocentric model]] and disproved the then conventional [[geocentric model]] (second image). |align=right |image1 = Phases-of-Venus2.svg| |image2 = Phases-of-Venus-Geocentric.svg|}} 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]]''), describing some of his discoveries: 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 [[sunspot]]s. Galileo's contributions caused difficulties for [[Theology|theologians]] and [[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. In particular, Galileo's observations of the phases of Venus, which showed it to circle the Sun, and the observation of moons orbiting Jupiter, contradicted the [[geocentric model]] of [[Ptolemy]], which was backed and accepted by the Roman Catholic Church,{{cite book |title=Ptolemy's Tetrabiblos; Or, Quadripartite Being Four Books of The influence of the Stars |first1=J. M. |last1=Ashmand |publisher=Library of Alexandria |year=1936 |isbn=978-1-61310-429-3 |page=1 |url=https://books.google.com/books?id=HphOkVo2JxkC}} [https://books.google.com/books?id=HphOkVo2JxkC&pg=PT1 Extract of page 1]{{cite book |title=How to Find a Habitable Planet |edition=illustrated |first1=James |last1=Kasting |publisher=Princeton University Press |year=2010 |isbn=978-0-691-13805-3 |page=4 |url=https://books.google.com/books?id=xPqEeB-SRvUC}} [https://books.google.com/books?id=xPqEeB-SRvUC&pg=PA4 Extract of page 4] and supported the Copernican model advanced by Galileo.{{cite book|last=Drake|first=Stillman|title=Essays on Galileo and the History and Philosophy of Science, Volume 1|date=1999|publisher=University of Toronto Press|location=Toronto|pages=292|url=https://books.google.com/books?id=sp8_hrRI2MoC|isbn=978-0-8020-7585-7}} [[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 [[Johannes Kepler|Kepler]] of August 1610,[[#Reference-Drake-1978|Drake (1978, p. 162)]], [[#Reference-Sharratt-1994|Sharratt (1994, p. 86)]], [[#Reference-Favaro-1890|Favaro]] [http://moro.imss.fi.it/lettura/LetturaWEB.DLL?MODO=PAGINA&VOLPAG=10-421 (1900, 10:421–423)] {{webarchive |url=https://web.archive.org/web/20070927230546/http://moro.imss.fi.it/lettura/LetturaWEB.DLL?MODO=PAGINA&VOLPAG=10-421 |date=September 27, 2007 }} {{in lang|la}}. Galileo complained that some of the philosophers who opposed his discoveries had refused even to look through a telescope:Galileo did not name the philosophers concerned, but Galileo scholars have identified two of them as [[Cesare Cremonini (philosopher)|Cesare Cremonini]] and Giulio Libri [[#Reference-Drake-1978|(Drake, 1978, pp. 162, 165]]; [[#Reference-Sharratt-1994|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. {{blockquote|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.[[#Reference-Favaro-1890|Favaro]], [http://moro.imss.fi.it/lettura/LetturaWEB.DLL?MODO=PAGINA&VOLPAG=10-423 (1900, 10:423)] {{webarchive|url=https://web.archive.org/web/20110718004557/http://moro.imss.fi.it/lettura/LetturaWEB.DLL?MODO=PAGINA&VOLPAG=10-423 |date=July 18, 2011 }} {{in lang|la}}. 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{{snd}}[[#Reference-bethune-1830|Bethune]] [https://archive.org/stream/lifeofgalileogal00bethrich#page/n39/mode/2up (1830, p. 29)], [[#Reference-Fahie-2005|Fahie]] [https://books.google.com/books?id=dnn66vXxD2YC&pg=PA102&lpg=PA102 (2005, p. 102)], [[#Reference-Lodge-2003|Lodge]] [https://books.google.com/books?id=LrYlZ0ncgHcC&pg=PT117 (2003, p. 106)]{{Dead link|date=September 2023 |bot=InternetArchiveBot |fix-attempted=yes }}, and [[#Reference-Santillana-1976|de Santillana]] [https://books.google.com/books?id=RABIZBnf_y4C&pg=PA9 (1976, p. 9)], for example.}} [[File:Ptolemaeus.jpg|thumb|left|upright|[[Claudius Ptolemy]] (A.D. 90–168), whose [[Geocentrism|geocentric]] system was adopted by the Catholic Church, and supplanted by the work of [[Nicholas Copernicus|Copernicus]] and [[Galileo Galilei|Galileo]] in the 16th and 17th centuries.]] In 1611, the same year that Galileo visited the Collegium Romanum, his theories first came to the attention of the Roman Inquisition. A commission of cardinals working with the inquisition made inquiries into Galileo's activities, and asked the city of Padua if he had any connections to [[Cesare Cremonini (philosopher)|Cesare Cremonini]], a professor at the university of Padua who had been charged with heresy by the Inquisition. These inquiries marked the first time Galileo's name was brought before the inquisition.Bucciantini, Massimo; Camerota, Michele; Giudice, Franco (2015). ''Galileo's Telescope'' [''Il telescopia di Galileo: Una storia europea'']. Cambridge, Massachusetts: Harvard University Press. p. 4. {{ISBN|978-0-674-73691-7}}. Geocentrists who did verify and accept Galileo's findings had an alternative to Ptolemy's model in an [[Tychonic system|alternative geocentric (or "geo-heliocentric") model]] proposed some decades earlier by [[Tycho Brahe]] – a model in which, for example, Venus circled the Sun. Tycho argued that the distance to the stars in the Copernican system would have to be 700 times greater than the distance from the Sun to Saturn. (The nearest star other than the Sun, Proxima Centauri, is over 28,000 times the distance from the Sun to Saturn.) Moreover, the only way the stars could be so distant and still appear the sizes they do in the sky would be if even average stars were gigantic – at least as big as the orbit of the Earth, and of course vastly larger than the Sun. (See the articles on the [[Tychonic System]] and [[Stellar parallax]].) Galileo became involved in a dispute over priority in the discovery of sunspots with [[Christoph Scheiner]], a Jesuit. This became a bitter lifelong feud. Neither of them, however, was the first to recognise sunspots – [[Chinese astronomy|the Chinese]] had already been familiar with them for centuries.[[#Reference-Sharratt-1994|Sharratt (1994, p. 98)]]. 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 such as the Florentine nobleman [[Lodovico delle Colombe]]. During this controversy one of Galileo's friends, the painter [[Cigoli|Lodovico Cardi da Cigoli]], informed him that a group of malicious opponents led by delle Colombe, which Cigoli subsequently referred to derisively as "the Pigeon league","La legha del Pippione" [[#Reference-Favaro-1890|(Favaro]], [http://moro.imss.fi.it/lettura/LetturaWEB.DLL?MODO=PAGINA&VOLPAG=11-476 1901, 11:476)] {{in lang|it}}. "The Pigeon" ("il Pippione") was Cigoli's derisive nickname for the presumed leader of the group, Lodovico delle Colombe [[#Reference-Sharratt-1994|(Sharratt, 1994, p. 95]]; [[#Reference-Favaro-1890|Favaro]], [http://moro.imss.fi.it/lettura/LetturaWEB.DLL?MODO=PAGINA&VOLPAG=11-176 1901, 11:176], [http://moro.imss.fi.it/lettura/LetturaWEB.DLL?MODO=PAGINA&VOLPAG=11-228 11:228–229], {{webarchive |url=https://web.archive.org/web/20090221173004/http://moro.imss.fi.it/lettura/LetturaWEB.DLL?MODO=PAGINA&VOLPAG=11-228 |date=February 21, 2009 }} [http://moro.imss.fi.it/lettura/LetturaWEB.DLL?MODO=PAGINA&VOLPAG=11-502 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{{snd}}besides meaning "young pigeon", it was also a jocular colloquialism for a testicle, and a Tuscan dialect word for a fool. was plotting to cause him trouble over the motion of the Earth, or anything else that would serve the purpose.[[#Reference-Drake-1978|Drake (1978, p. 180)]], [[#Reference-Favaro-1890|Favaro (1901)]] [http://moro.imss.fi.it/lettura/LetturaWEB.DLL?MODO=PAGINA&VOLPAG=11-241 11:241–242)] {{webarchive |url=https://web.archive.org/web/20090221180154/http://moro.imss.fi.it/lettura/LetturaWEB.DLL?MODO=PAGINA&VOLPAG=11-241 |date=February 21, 2009 }} {{in lang|it}}. According to Cigoli, one of the plotters asked a priest to denounce Galileo's views from the pulpit, but the latter refused. Nevertheless, three years later another priest, [[Tommaso Caccini]], a member of the "Pigeon League",{{Cite web |last=Van Helden |first=Al |date=1995 |title=Tommaso Caccini |url=http://galileo.rice.edu/chr/caccini.html |access-date=2023-01-13 |website=The Galileo Project |via=[[Rice University]]}} did in fact do precisely that, [[#caccinisermon|as described below]]. == Bible argument == {{Main|Biblical cosmology}}{{Further|Biblical inerrancy}} In the Catholic world prior to Galileo's conflict with the Church, the majority of educated people subscribed to the Aristotelian [[geocentrism|geocentric]] view that the Earth was the centre of the universe and that all heavenly bodies revolved around the Earth,{{cite book|last=Blackwell|first=Richard|title=Galileo, Bellarmine, and the Bible|date=1991|publisher=University of Notre Dame Press|location=Notre Dame|isbn=0-268-01024-2|page=25|url=https://books.google.com/books?id=MHnwAAAAMAAJ}} though [[Nicolaus Copernicus|Copernican]] theories were used to reform the calendar in 1582."The Gregorian calendar, first adopted in 1582, was in fact based on computations that made use of Copernicus' work." {{cite book|author=Thomas Kuhn|title=The Copernican Revolution|url=https://archive.org/details/copernicanrevolu0008kuhn|url-access=registration|page=[https://archive.org/details/copernicanrevolu0008kuhn/page/125 125]|date=1957|publisher=Harvard University Press}} [[File:God the Geometer.jpg|thumb|upright|Christian painting of God creating the cosmos (Bible Moralisee, French, 13th century)]] Geostaticism agreed with a [[Biblical literalism|literal interpretation]] of Scripture in several places, such as {{bibleverse|1 Chronicles|16:30}}, {{bibleverse|Psalm|93:1}}, {{bibleverse|Psalm|96:10}}, {{bibleverse|Psalm|104:5}}, {{bibleverse|Ecclesiastes|1:5}} (but see varied interpretations of {{bibleverse|Job|26:7}}). [[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]].''Four Treatises for the Reconsideration of the History of Science'', Fabio J. a. FarinaHeilbron (2010), p. 369 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.{{cite book|last=Langford|first=Jerome J.|title=Galileo, science, and the church (with foreword by Stillman Drake)|date=1992|publisher=University of Michigan Press|location=Ann Arbor|isbn=0-472-06510-6|page=54|url=https://books.google.com/books?id=zcDrMlJjlLoC|edition=3rd}} – Letter from Benedetto Castelli to Galileo, 1613–14Galileo was defended on the spot by his former student [[Benedetto Castelli]], now a professor of mathematics and [[Benedictine]] [[abbot]]. The exchange having been reported to Galileo by Castelli, Galileo decided to write a [[Letter to Benedetto Castelli|letter to Castelli]],{{cite web |url=http://www.law.umkc.edu/faculty/projects/ftrials/galileo/lettercastelli.html |title=Letter from Galileo to Cardinal Dini (May, 1615) |access-date=2011-02-06 |url-status=dead |archive-url=https://web.archive.org/web/20110206071010/http://www.law.umkc.edu/faculty/projects/ftrials/galileo/lettercastelli.html |archive-date=2011-02-06 }} expounding his views on what he considered the most appropriate way of treating scriptural passages which made assertions about natural phenomena.[[#Reference-Sharratt-1994|Sharratt (1994, p. 109)]]. Later, in 1615, he expanded this into his much longer ''[[Letter to Grand Duchess Christina|Letter to the Grand Duchess Christina]]''.[[#Reference-Sharratt-1994|Sharratt (1994, pp. 112–126)]].