Astronomy and Censorship

Definition: Scientific study of celestial bodies

Significance: Efforts to impede the progress of astronomy by various kinds of censure and censorship have occurred throughout history, but they have seldom been successful for very long and have sometimes even aided astronomy’s development

Astronomy has often come into conflict with prevailing religious ideas and has occasionally suffered from attempts to hinder its progress. In the ancient world, celestial bodies were often worshipped as deities, and efforts to understand and explain them as natural phenomena were viewed as impious attacks on religion. The medieval synthesis of Christianity with Aristotelian science in the thirteenth century clashed with later innovations in astronomy, leading to theological conflicts with the Roman Catholic Church and official censorship.

Ancient and Medieval Astronomy

At Athens in the fifth century BCE, Anaxagoras taught that celestial bodies were not deities but material objects. He claimed that the moon was made of earth and the sun was a flaming stone, and he explained for the first time that the phases of the moon are the result of reflected light from the sun. As a result, he was persecuted for impiety, jailed, and banished from Athens. Some years later, Meletus accused Socrates at his trial in 399 BCE of teaching that the sun is a stone and the moon is made of earth. In his unsuccessful defense, Socrates credited Anaxagoras with these teachings. Plato was finally able to remove the scandal associated with these ideas and obtain their general acceptance.

In the third century BCE, Aristarchus of Samos taught that the earth revolves around the sun, leading to his later reputation as the Copernicus of antiquity. In his dialogue “On the Face in the Round of the Moon” (in Moralia, ca. 100 CE), Plutarch asserted that Cleanthes, the second head of the Stoic school, thought that Aristarchus ought to be indicted on a charge of impiety for putting the earth in motion. This was contrary to the then-popular geocentric view of the world. Renowned Renaissance-era astronomer Nicolaus Copernicus learned of Aristarchus’ ideas from this source.

In the thirteenth century, the idea of the permanence and perfection of the heavens was revived within Christendom by the work of Thomas Aquinas in his great synthesis of Aristotelian science with Christian theology. In 1277, at the instigation of Pope John XXI, the bishop of Paris, Etienne Tempier, issued a blanket condemnation of 219 propositions, the holding of any of which was punishable by excommunication. Many of the propositions involved Aristotelian science, including statements that God could not make several worlds, God could not produce something new, God could not make a vacuum, and the elements are eternal. Such ideas were condemned because they imposed limits on the absolute power of God.

In spite of this condemnation, the influence of Aristotelian science continued for more than three centuries, partly because of the growing acceptance of the Thomistic synthesis by theologians. In fact, the condemnation only applied locally and was finally annulled in 1325. It has been suggested that the condemnation had a positive effect on astronomy because it forced scientists to think in new ways and to entertain possibilities that Aristotelian science had considered impossible, such as the idea that perhaps God could make several worlds after all.

The Scientific Revolution

The demise of Aristotelian science began with the revival of heliocentric theory by Copernicus in the sixteenth century, although more than a century passed before the theory was widely accepted. Copernicus delayed publication of his controversial book until the year of his death in 1543 but experienced no opposition from the Roman Catholic Church. In 1559 Pope Paul IV issued the first official Index Librorum Prohibitorum , which did not ban any works related to Copernican theory. Pope Pius V established the Congregation of the Index to oversee censorship in 1571, but no Catholic astronomers worked under the formal prohibitions of either the Index or the Inquisition throughout the sixteenth century.

At the end of the sixteenth century, several natural philosophers came under scrutiny by the Roman Inquisition. One of the few Copernicans at the time was Giordano Bruno, who was the first to teach that stars are suns with their own populated planets and that the universe contains an infinite number of such worlds spread throughout infinite space. He was arrested by the Inquisition in 1592 for his pantheistic ideas. Bruno was burned at the stake in 1600, and all of his writings were prohibited.

In 1609 Galileo Galilei became the first person to use the telescope, which had been invented in the Netherlands the year before, to study the heavens. His discovery of mountains on the moon and spots on the sun convinced him that Aristotle was wrong in claiming the perfection of the celestial realm, and his discovery of the moons of Jupiter and the phases of Venus supported his growing Copernican convictions. Although these discoveries did not actually prove the heliocentric theory, he began to argue more strongly that the earth moves around the sun. In 1616 Galileo was warned by the Holy Office that the idea of a moving earth was expressly condemned. Copernicus’s book De revolutionibus orbium coelestium (1543; On the Revolutions of the Heavenly Spheres, 1939) was placed on the Index, but Galileo and his works were spared condemnation.

After the election of Pope Urban VIII in 1623, Galileo received permission to write about the motion of the earth as a scientific hypothesis. He submitted his manuscript to the chief censor at Rome in 1630 and was given permission to publish it after several minor revisions. His masterpiece, the Dialogo sopra i due massimi sistemi del mondo (Dialogue Concerning the Two Chief World Systems, 1953), appeared in 1632 with a concluding paragraph, suggested by Pope Urban, stating that the Copernican theory was neither true nor conclusive. Galileo put these words in the mouth of a character called Simplicio, who represented Galileo’s scholastic opposition. Sale of the book was stopped, and Galileo was summoned to Rome. After trial by the Inquisition in 1633, he was judged guilty, and the book was banned. On June 22, 1636, at the age of seventy, Galileo was required to kneel before the tribunal and recant his belief in the reality of the Copernican system. He was then sentenced to house arrest at his country estate, with no visitors allowed except by special permission.

As a result of Galileo’s conviction, progress in astronomy shifted from Italy to northern Europe and England. After Isaac Newton and others had confirmed the heliocentric model of the planets, Copernicus’s book was removed from the Index Librorum Prohibitorum in 1832, and Catholics were allowed to teach Copernicanism with complete freedom.

Bibliography

Alioto, Anthony M. A History of Western Science. 2nd ed. Englewood Cliffs: Prentice, 1993. Print.

Chapman, Allan. Stargazers: Copernicus, Galileo, the Telescope and the Church. Oxford: Lion, 2014. Print.

Draper, John William. History of the Conflict Between Religion and Science. 1874. New York: Cosimo, 2005. Print.

Lindberg, David C., and Ronald L. Numbers, eds. God and Nature: Historical Essays on the Encounter between Christianity and Science. Berkeley: U of California P, 1986. Print.

McMullin, Ernan, ed. The Church and Galileo. Notre Dame: U of Notre Dame P, 2005. Print.

Spradley, Joseph L. Visions That Shaped the Universe: A History of Scientific Ideas about the Universe. Dubuque: Brown, 1995. Print.

White, Andrew Dickson. A History of the Warfare of Science with Theology in Christendom: From Creation to the Victory of Scientific and Literary Methods. 1896. Introd. Tom Flynn. New Brunswick: Transaction, 2012. Print.