When will science apologize for Galileo?

Standing in the Florentine Church where Galileo Galilei was entombed, I could scarcely believe my ears. "Galileo," our young tour guide was saying, "proved that the earth goes round the sun." This, he told us, led to the church's condemnation of the seventeenth-century astronomer.

Of course, Galileo proved no such thing, although he certainly tried. I thought that in Catholic Italy I would get the straight story; but such is the power of propaganda that this damnable and damning lie circulates unchallenged in the very shadow of the Vatican, as it were.

Centre of the universe

The issue that brought Galileo and the Church into conflict was whether the earth or the sun is the immovable centre of the universe. The Ptolemaic or geocentric theory had held sway since the second century. It proposed that the sun, moon, planets, and stars revolve around a stationary earth. The Copernican or heliocentric theory challenged the Ptolemaic conception in the sixteenth century. It proposed that the earth rotates on its axis, and together with the other celestial bodies revolves around a stationary sun.

In a sense, the Church condemned Galileo not because he proved the heliocentric theory but because he failed to prove it. He insisted on teaching the theory as fact, even though seventeenth-century science was not sophisticated enough to verify it. Indeed, one of his famous contemporaries, astronomer Tycho Brahe, rejected the theory. Church authorities were interested in the question because of biblical passages that could be interpreted as supporting the Ptolemaic theory. They generally took the position that as long as scientists could not prove the heliocentric theory, Galileo should not teach it as fact. [1]

To an extent, both sides were in the wrong. The church has since apologized on behalf of its seventeenth-century representatives. So far as I know, the scientific community has not apologized on behalf of Galileo. Perhaps the apology should come from Stephen Hawking, who was born on the three-hundredth anniversary of Galileo's death and is a great admirer of the Italian astronomer. Hawking recognizes that "any physical theory is always provisional, in the sense that it is only a hypothesis...." He is also humble enough to admit his mistakes, as when he abandoned the belief that disorder would decrease as the expanding universe recollapsed. [2]

By treating Galileo's teaching as heretical, the Holy Office was clearly in error. For one thing, the Church had not pronounced infallibly on the Copernican system and therefore neither the immobility of the earth nor the mobility of the sun was a matter of faith. This was well understood by Catholic philosophers and theologians of the day.

For another thing, St. Augustine in the fourth century and St. Thomas Aquinas in the thirteenth century had declared that the Bible was meant to teach truths of religion, not of natural science. Augustine stated that in speaking through the biblical authors, the Holy Spirit "did not wish to teach things which contribute nothing to salvation." Aquinas stated repeatedly that in matters of physical science, the scripture writers adopted the conceptions and modes of speech that their people commonly used. [3]

Language of the Bible

We must distinguish, in other words, between the religious teachings the Bible presents and the language in which it presents them. The teachings, Christians believe, are religiously true, because God has revealed them. The language may or may not be geologically, astronomically, or mathematically accurate, because its purpose is to present divine revelation in images that people can understand, not to teach geology, astronomy or mathematics.

We make these kinds of distinctions all the time. If somebody remarks that the sun rose at six o'clock this morning, we know that he means to take note of the hour at which it first appeared above the horizon. We do not believe that he thinks the sun moves while the earth does not. We do not suspect him of trying to resurrect the Ptolemaic system of astronomy. If somebody says she is flying straight from New York to Mexico City, we do not remind her that the world his round. We know she means to tell us that she is flying non-stop, not that she has joined the Flat Earth Society.

The Bible, of course, is not one book but several, which were written in different times for different peoples. Consequently, we should expect it to present the same truths in different images, and it does. The revelation that God created the universe, for example, is a continuing biblical theme, for which the imagery differs to accommodate a continually developing way of thinking. Genesis, the psalms, wisdom literature and the Gospel of St. John all present the creation theme differently. In the Bible, "the images are free and they correct themselves ongoingly. In this way they show, by means of a gradual and interreactive process, that they are only images, which reveal something deeper and greater." [4]

For his part, Galileo insisted on the truth of a scientific theory that he could not prove. Proof of the theory, in fact, did not become available until well into the nineteenth century. His attempt to use tidal motion to show that the earth moves failed. The correlation of tides with lunar periods was well known in the seventeenth century.

Many influential churchmen nevertheless believed that he might be right about the earth's mobility. Jesuit astronomers who had confirmed discoveries he made with his telescope eagerly awaited proof of the Copernican system. Cardinal Robert Bellarmine was ready to revise the accepted scriptural interpretation once proof was forthcoming. "Prove your theory," he said, "and we will change our exegesis, otherwise teach it as a hypothesis ...." [5]

Galileo failed to prove thesis

Matters might have turned out differently if Galileo had accepted his inability to prove it, but he refused to compromise. He failed to see that people were "not about to accept, on his word alone, an entirely new view of the universe." [6] Matters might also have turned out differently if someone of the stature of Augustine or Aquinas had been around to remind the theologians that the Bible is not a science text. It was, of course, a difficult time for the Church, which was reeling from the trauma of the Reformation. It was a time, in fact, when Catholics and Protestants alike were overly sensitive to suggested changes in the meaning of biblical passages that both had interpreted literally.

Human frailty was also a factor. Galileo claimed credit for a discovery that he did not make and mocked scholars who held views that differed from his own. He claimed, falsely, to have been the "first discoverer" of sun spots "as also of all other celestial novelties." He characterized his opponents as "mental pygmies," non-rational animals, and "pedantic maintainers of whatever came from Aristotle's pen." He thus alienated people who might have supported him in his dispute with the Holy Office. [7] This does not justify the reaction against him, but it may help to explain it.

Regrettable as it was, the condemnation did little to inhibit Catholic scientists or the development of science. Anyone who took the trouble to obtain permission could read the works of both Copernicus and Galileo. Anyone was free to write on the heliocentric system as a hypothesis and to seek an irrefutable mathematical or physical proof of the mobility of the earth. [8] In 1838, it was conclusively proved that the earth moves and the geocentric theory is incorrect. Today, we know that the heliocentric theory is also incorrect. The sun is not the centre of the universe, but only of the solar system.

Critics of the magisterium have made the Galileo case a cause celebre. I have even heard it argued that the Church should retreat from its condemnation of contraception to avoid another Galileo fiasco. But, as the foregoing shows, the real issue in the Galileo episode was neither faith nor morals. It was the appropriateness, in a very sensitive time, of presenting as fact what was still only a theory.

Joseph Campbell is a former director of communications at the University of Saskatchewan. A freelance writer, he lives in Saskatoon, SK.

Footnotes

(1.) Jerome J. Langford, Galileo, Science and the Church, third edition (University of Michigan: Ann Arbor Paperbacks, 1992), pp. 46-8, 68.

(2.) Stephen W. Hawking, A Brief History of Time: From the Big Bang to Black Holes (Toronto: Bantam Books, 1988), pp. 10, 150-1.

(3.) Langford, pp. 64-6, 155-6.

(4.) Cardinal Joseph Ratzinger, In the Beginning ... A Catholic Understanding of the Story of Creation and the Fall, translated by Boniface Ramsey, O.P. (Huntington, Indiana: Our Sunday Visitor Publishing, 1990) pp. 17-25.;

(5.) Langford, pp. 68-9.

(6.) Langford, p. 160.;

(7.) Langford, pp. 438-9, 120, 124, 140, 160.

(8.) See J. Donat, The Freedom of Science (New York: Wagner, 1914), p. 196, cited in Langford, p. 157.