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The Religious Affiliation of Astronomer, Scientist
Galileo Galilei

Galileo remained a devout Catholic throughout his life. "Affiliation: Catholic; It is known to everyone that Galileo was denounced to the Inquisition in 1615 and that he was tried and condemned by the Inquisition in 1633, living the rest of his life under house arrest. All of this was for Copernicanism, not for any heretical theological views." [Source: The Galileo Project;; viewed 12 July 2005]. Additionally, it may be noted that although Galileo himself did not consider his writings about heliocentricity to be heretical, his Catholic leaders at that time did. Today the Catholic Church does not consider heliocentricity or any of Galileo's writings to be heretical.

From: Rich Deem, "Famous Scientists Who Believed in God", last modified 19 May 2005, on "Evidence for God from Science" website (; viewed 5 October 2005):

Galileo is often remembered for his conflict with the Roman Catholic Church. His controversial work on the solar system was published in 1633. It had no proofs of a sun-centered system (Galileo's telescope discoveries did not indicate a moving earth) and his one "proof" based upon the tides was invalid. It ignored the correct elliptical orbits of planets published twenty five years earlier by Kepler. Since his work finished by putting the Pope's favorite argument in the mouth of the simpleton in the dialogue, the Pope (an old friend of Galileo's) was very offended. After the "trial" and being forbidden to teach the sun-centered system, Galileo did his most useful theoretical work, which was on dynamics. Galileo expressly said that the Bible cannot err, he saw his system as concerning the issue of how the Bible should be interpreted.

[Sources:] Annibale Fantoli, Galileo: For Copernicanism and for the Church (1994), M. Sharratt, Galileo (1994), M. A. Finnochiaro, The Galileo Affair: A Documentary History (1989)

From: Michael H. Hart, The 100: A Ranking of the Most Influential Persons in History, Hart Publishing Company, New York City (1978), pages 102-104: The invention of the telescope and the series of discoveries that resulted from it made Galileo famous. However, by supporting the theory of Copernicus he aroused opposition in important [Catholic] Church circles, and in 1616 he was ordered to refrain from teaching the Copernican hypothesis. Galileo chafed under this restriction for several years. When the Pope died, in 1623, he was succeeded by a man who had been an admirer of Galileo. The following year the new Pope, Urban VIII, hinted (though somewhat ambiguously) that the prohibition would no longer be in force.

Galileo spent the next six years composing his most famous work, the Dialogue Concerning the Two Chief World Systems. This book was a masterly exposition of the evidence in favor of the Copernican theory, and the book was published in 1632 with the imprimatur of the Church censors. Nevertheless, Church authorities responded in anger when the book appeared, and Galileo was soon brought to trial before the Inquisition of Rome on charges of having violated the 1616 prohibition.

It seems clear that many churchmen were unhappy with the decision to prosecute the eminent scientist. Even under the Church law of the time, the case against Galileo was questionable, and he was givena comparitively light sentence. He was not, in fact, confined to jail at all, but merely to house arrest in his own comfortable villa in Arcetri. Theoretically, he was to have no visitors, but that provision of the sentence was not enforced. His only other punishment was the requirement that he publicly recant hs view that the earth moved around the sun. This the sixty-nine-year-old scientist did in open court. (There is a famous and probably apocryphal story that after he finished making his retraction, Galileo looked down to the earth and whispered softly, "It still moves.") In Arcetri he continued to write on mechanics. He did there, in 1642...

[page 103] Galileo is probably more responsible than any other man for the empirical attitude of scientific research. It was he who first insisted upon the necessity of performing experiments. He rejected the notion that scientific questions could be decided by reliance upon authority, whether it be the pronouncements of the Church of the assertions of Aristotle. He also rejected reliance on complex deductive schemes that were not based on a firm foundation of experiment. Medieval scholastics had discussed at great length what should happen and why things happen, but Galileo insisted upon performing experiments to determine what actually did happen. His scientific outlook was distinctly non-mystical; in this respect, he was even more modern than some of his successors, such as Newton.

Galileo, it might be noted, was a deeply religious man. Despite his trial and conviction, he did not reject either religion or the church, but only the attempt of Church authoritie to stifle investigation of scientific matters. Later generations have quite righlty admired Galileo as a symbol of revolt against dogmatism, and against authoritarian attempts to stifle freedom of thought. Of greater importance, however, is the role he played in founding modern scientific method.


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Webpage created 12 July 2005. Last modified 5 October 2005.
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