Ideas of Scientists that Challenged Popular Beliefs in Society and the Religious Establishment

Ideas of Scientists that Challenged Popular Beliefs in Society and the Religious Establishment

Galileo versus the Catholic Church

Galileo was a devout catholic. He in fact trusted the church to educate one of his daughters who later became a nun (see Galileo's Daughter). His Daughter Suor Maria Celeste (born Virginia) was devoted to Galileo all of his life and was a great source of spiritual strength for him through their life-long correspondence.

Using a telescope that improved upon the original design of the Dutch lens-grinder Hans Lipperhey, Galileo was able to observe and make the first sketches of the sun, moon, and planets (including the 4 moons of Jupiter; moving Sun spots; and Venus showing that its phases resembled those of the moon, and the rings of Saturn). His descriptions of the moon's surface with its craters, and mountains and shadows caused some controversy by calling into question popular belief then supported by the church (and first stated by Aristotle) that all of the planets and stars surrounding the earth were smooth perfect spheres. Of course "God's Kingdom" hovered over all of the planets and stars. There were no serious consequences of Galileo's observations and he invited the clergy to make their own observations with the telescope. He even sold telescopes to church members as well as to merchants and other members of the Venice Senate. The church members also observed the irregularities of the moon's surface and probably did not choose to pursue the matter further.

More serious controversies arose later as a result of Galileo's defense of Copernicus's heliocentric theory of the universe. Heliocentric refers to the theory that the sun and not the earth is the center of the universe. In other words, the earth moves around the sun and not the other way around. Copernicus's publishing of this theory preceded Galileo by over 60 years. Copernicus did not actually prove that the earth revolves around the sun (he had no new evidence). He, however, considered that his theory was more internally consistent and had more explanatory power than the geocentric theory of Ptolemy. Copernicus died in 1543 (21 years before Galileo was born in 1564) with the publication of his book the Revolutions of the Celestial Spheres. This book appeared at a time during which the Protestant Reformation was at its height and at the beginning of the Counter Reformation. The church had adopted decisions after the council of Trent (1545 to 1563) which stated that only the church had the power to interpret the bible. Church authorities preferred the geocentric (earth centered) model of the heavens (proposed by Aristotle around mid-300 BC and refined by Ptolemy ) and were in no mood to have their authority challenged by any new revolutionary theories. It needs to be emphasized here that the church in these times was extremely sensitive and defensive to anyone challenging the orthodox interpretation of scripture due to fears of a split in the church between western and northern Europe.

Even in Galileo's day the heliocentric theory was not yet conclusively proven even though evidence was mounting to support this assertion. Galileo published his book the "Starry Messenger" defending the heliocentric theory in 1610. Galileo reported that the planet Venus went through phases similar to the Moon. This lent support to the fact that Venus revolves around the sun and showed that Ptolemy's theory was wrong in this respect. This however was not conclusive proof for the heliocentric theory.

The church condemned the heliocentric theory as false and completely contrary to the "Divine Scriptures " in 1616. Galileo's writings were not mentioned in the decree. Copernicus's book, Revolutions of the Celestial Spheres was prohibited. It was however published 4 years later after removal of the first chapter and censoring other sentences discussing the motion of the earth. During a visit to Rome in 1616 Galileo was required to meet with Cardinal Bellarmine at the request of Pope Paul V. Cardinal Bellarmine took the position that as long as the heliocentric theory was not indisputably proven, the higher truth of the bible should be accepted. Bellarmine held that since God is the author of every statement in the bible, it must be true when properly understood and therefore any loyal Christian would have to accept its statements as true based on religious faith. It was church policy at the time that all historical knowledge about the natural world mentioned in the bible would fall within the scope of religious faith and was to be interpreted by the church.

It is not clear what happened during the meeting between Cardinal Bellarmine and Galileo. It is thought that Galileo was either simply informed about the upcoming papal decree declaring that the heliocentric theory could not be "defended or held," or that Galileo received a stronger injunction "not to hold, teach, or defend," [Copernicanism] in any way whatsoever, verbally or in writing."

Following this papal decree, Galileo avoided the issue of heliocentrism until 1623 when a new pope was elected. Pope Urban VIII (formerly Maffeo Barberini) had been an early personal acquaintance of Galileo and a man of letters in his own right. Galileo visited him in Rome and met with him on 6 different occasions. Apparently the pope told Galileo that he could write about heliocentrism as long as he kept the discussion hypothetical. Believing that the political and religious climate would now change, Galileo wrote and published in 1632 the Dialogue Concerning the Two Chief World Systems that presented a Platonian style debate between three individuals, Salvati who represented the new idea of heliocentrism, Simplico who represented the old geocentric tradition, and Sagredo who represented an open-minded inquirer who would assess the issues from a neutral point of view. The book was a sensation at the time and most readers concluded then and since that time, that Salvati won the debate and that this was a victory for heliocentrism.

A special commission was appointed by the pope to investigate whether this book violated the Decree of 1616 against Copernicanism. During the inquiry the documents related to the older injunction resulting from Galileo's meeting in 1616 with Cardinal Bellarmine were uncovered. The commission judged that Galileo had exceeded the instructions given to him to only discuss the heliocentric theory hypothetically. The pope was angered and Galileo was called before the Inquisition to decide whether the injunction was indeed violated and whether Galileo had received the required approvals from the church before publishing his book.

Although Galileo had a 1616 letter from Cardinal Bellarmine that made no mention of the injunction but only mentioned "defending and holding" views on Copernicanism, the church evidence citing the stronger injunction in another letter prevailed. During the whole trial there was no real discussion of the scientific truth of the heliocentric theory or the proper use of the bible in relation to science.

Galileo was "vehemently suspected of heresy" by the Inquisition for his defense of the heliocentric theory in 1633. He was forced to read an oath prepared by the court denouncing his own teachings. Already an old man, Galileo lived the rest of this life in disgrace under house arrest in his own home in Arcerti near Florence. During this time he did produce the Discourse on Two New Sciences which comprises his major contribution to physics. In the centuries following the church's decision in the Galileo affair, there was a low point in the relationship between organized religion and the scientific community. Much scientific investigation shifted thereafter from southern to northern Europe.

Copernicus's book, the Revolutions of the Celestial Spheres was kept on an Index of literature forbidden by the church until around 1835. The trial of Galileo still dominates discussions with respect to the relationship between organized religion and the scientific community with distrust on both sides still being not far below the surface.
The trial of Galileo has been popularized in a play written by Bertolt Brecht (Life of Galileo first published in 1940). It was not until 1992 that Pope John Paul II who had commissioned an investigation of the affair in 1979, restated the aphorism that Galileo himself had stated that "the Bible tells how to go to heaven but not how the heavens go." The pope declared that Galileo had been a better theologian than those who opposed him. One can say of this statement that it is better to have come later than never, however at this pace what can one really expect with regard to an effective dialogue between the scientific establishment and religious leaders regarding burning ethical issues today (e.g. cloning, stem cell research, confidential use of genetic information and the rights of individuals).