This article is taken from the last number of ENEL’s magazine, Oxygen

In the discourse prepared for the Pope, the Galileo affair is described as a “tragic mutual incomprehension” and the incomprehension is specified by what can be identified as the following four principal conclusions of the two discourses: 

1 Galileo is said not to have understood that, at that time, Copernicanism was only “hypothetical” and that he did not have scientific proofs for it; thus he betrayed the very methods of modern science of which he was a founder;
2 it is further claimed that “theologians” were not able, at that time, to correctly understand Scripture;
3 Cardinal Robert Bellarmine is said to have understood what was “really at stake”;
4 when scientific proofs for Copernicanism became known, the Church hastened to accept Copernicanism and to implicitly admit it erred in condemning it.

It will not be possible to discuss all four conclusions, but I would like to make some selective comments about numbers 1 and 3. It is said that Galileo did not understand the difference between science and philosophy. He would not accept Copernicanism as “hypothetical” and, thus, did not understand science, even though he was one of the founders of it. Much could be said about this characterization of the scientific method and Galileo’s use of it. I limit myself to discussing the ambiguity involved in the use of the word “hypothesis.” There are two distinctly different uses of the word in this context: a purely mathematical expedient to predict celestial events or an attempt to understand the true nature of the heavens. This important difference in meaning must be seen against the history of the word’s use from antiquity through medieval Christianity to the time of Copernicus through to Galileo.

The best historical example of this is, of course, the case of Osiander. In his attempt to save Copernicus, Osiander, unbeknownst to the author and contrary to the latter’s intent, wrote his famous preface to advise the reader that the De Revolutionibus was intended, in the tradition of medieval astronomy, only in the former sense, as a mathematical expedient. There is no doubt that Galileo understood his own investigations to be an attempt to understand the true nature of things. It is well known that he preferred to be known as a philosopher of nature rather than as a mathematician. It can be debated as to whether Galileo himself was ever convinced that he had irrefutable proofs for Copernicanism (involved in that debate would be the very meaning of “proof” for him and for us) but it cannot be denied that he sought evidence to show that Copernicanism was really true and not just a mathematical expedient. Galileo rejected the claim that Copernicanism was a hypothesis in the former sense. He sought to find experimental verification of it in the latter sense. He can certainly not be accused of betraying the very method “of which be was the inspired founder.”

The Commission’s report claims that, in contrast to “most” theologians, Bellarmine had seen what was truly at stake in the debate, since he personally felt that, in the face of possible scientific proofs that the Earth orbited around the Sun, one should “interpret with great circumspection” every biblical passage which seems to affirm that the Earth is immobile and “say that we do not understand rather than affirm that what has been demonstrated is false.” This view of Bellarmine comes from his Letter to Foscarini and the Commission draws two conclusions from the Letter, which appear to make Bellarmine both the most open-minded of theologians and respectful of science. One must, according to this interpretation of Bellarmine, be circumspect in interpreting Scriptural statements about natural phenomena in the face of possible scientific proofs contrary to the interpretation. If such proofs are forthcoming, one must reinterpret Scripture. Note that the epistemic primacy here is given to Scripture. Since Galileo had no irrefutable proofs of Copernicanism, the current interpretation of Scripture by theologians, including Bellarmine, should remain, but always subject to reinterpretation. Is this a correct presentation of Bellarmine’s position?

Bellarmine is interpreted as saying: “As long as there are no proofs for the movement of the Earth about the Sun, it is necessary to be cautious in interpreting Scripture.” What Bellarmine actually says is: “Should proofs be had, then we must go back and reinterpret Scripture.” The difference is: Bellarmine did not say: “Theologians should be cautious now in interpreting Scripture in expectation that proofs for Copernicanism might appear” but rather: “If a proof were to appear, then on that day in the future theologians would have to be cautious in interpreting Scripture.” If he truly believed that there might be a demonstration of Copernicanism, would he not have recommended waiting and not taking a stand, a position embraced at that time, it appears, by Cardinals Barberini and Caetani? And why did he agree to deliver the injunction to Galileo in 1616? This injunction prohibited Galileo from pursuing his research as regards Copernicanism. Galileo was forbidden to seek precisely those scientific demonstrations, which, according to Bellarmine, would have driven theologians back to reinterpret Scripture.

Final remarks

At the founding of the Galileo Commission and throughout its proceedings the case of Galileo is often referred to as a “myth” which arose from “a tragic mutual incomprehension.” I have discussed a few of the continuing incomprehension on the part of the Church. Does the “myth” continue? Myths are founded in concrete happenings. In the Galileo case the historical facts are that further research into the Copernican system was forbidden by the decrees of 1616 and then condemned in 1633 by official organs of the Church with the approbation of the reigning Pontiffs. This is what is at the source of the “myth” of Galileo and not a “tragic mutual incomprehension.” Galileo was a renowned world scientist. The publication of his Sidereus Nuncius established his role as a pioneer of modern science. He had provoked anew the Copernican-Ptolemaic controversy. Observational evidence was increasingly overturning Aristotelian natural philosophy, which was the foundation of geocentrism. Even if Copernicanism in the end proved to be wrong, the scientific evidence had to be pursued. A renowned scientist, such as Galileo, in those circumstances should have been allowed to continue his research. He was forbidden to do so by official declarations of the Church. There lies the tragedy. Until that tragedy is faced with the rigor of historical scholarship, the “myth” is almost certain to remain.

Astronomer and Jesus priest, George Coyne was the director of the Vatican Observatory from 1978 to 2006 and is currently head of the observatory’s research group based at the University of Arizona in Tucson.