Galileo Galilei was a first class physicist and mathematician and an excellent popularizer of science in the late 16th and early 17th centuries. He has become sort of a secular saint for his efforts to convince the world in general and the Catholic Church in particular that the heliocentric vision of the universe enunciated by Copernicus was not only an effective mathematical technique to “preserve the appearances,” but also was the only true description of the world. Indeed, Bertolt Brecht made him the hero of his play "Life of Galileo" as a martyr to intellectual freedom.

The problem raised by the Copernican theory is that it seemed to contradict certain passages in the Bible that assume the earth was the center of the cosmos. Galileo ended his life under house arrest imposed by the Congregation of the Holy Office (the Italian successor to the Inquisition) as punishment for advocating the Copernican view after having been ordered not to do so by Cardinal Roberto Bellarmine, who was a senior Vatican theologian and advisor to the Holy Office.

Copernicus first published his theory in 1543, 89 years before Galileo published Dialogue Concerning the Two Chief World Systems, the book that was the principal cause of his prosecution. So the heliocentric theory had been around for a long time before Galileo got into hot water. It should be noted that neither Copernicus nor Galileo was able to improve significantly on the accuracy of predictions by astronomers using Ptolemy’s earth-centered, but very complicated, theory of the cosmos. The reason for this failure was that all the astronomers assumed the planets moved in circular orbits. The author argues that it was only after Johannes Kepler demonstrated that the orbits were elliptical that truly accurate astronomical predictions could be made.

[The author claims Kepler was a superior scientist to Galileo because he first formulated the elliptical orbits. In that, the author is inaccurate. Kepler formulated three laws that implied that the orbits were elliptical, but did not expressly say so. Newton was the first to show the orbits were ellipses, and even came up with a theory of why that was so. To say Kepler was a superior scientist to Galileo seems absurd to me. Kepler came to his conclusions through a number of rationales, some of which were quite mystical and anything but scientific. He happened to get the right (or, to be more precise, more elegant) answer about planetary orbits partly because he had access to Tyco Brahe's remarkable data. Kepler made no other significant scientific discoveries.]

Galileo was not only an excellent physicist, he was probably the best fabricator of telescopes in the world at the time. Consequently, he was able to see phenomena (like four of Jupiter’s moons and the phases of Venus) that were invisible to astronomers using inferior optical instruments. Some of Galileo’s arguments for a sun-centered cosmos were interesting, but not logically dispositive. He could prove that Jupiter’s moons revolved around Jupiter, but even though that was the first time humans had directly observed heavenly rotation about a body other than the earth, that did not prove that the sun and the planets did not revolve around the Earth. Moreover, Galileo also asserted arguments from the motion of the tides that were simply wrong.

Galileo’s opus featured a discussion among three people debating the Copernican theory with little doubt with whom the author’s sympathies lay. Rowland’s book mirrors the structure of Galileo’s: it is structured as a dialog between a somewhat bumbling skeptic and a very intelligent and judicious nun, with Rowland serving as interlocutor.

Rowland’s thesis is that the Church was not as villainous nor was Galileo as heroic as popular history has portrayed them. The nature of the battle between Galileo and the Vatican was not merely the scientific one - it was over the nature of truth and who had the best access to it. Galileo argued that if the Bible seemed to contradict what he had demonstrated through what is now called the scientific method, then the Bible had to be reinterpreted to conform to the science. The Church, according to Rowland, thought Galileo was jumping the gun on the scientific conclusions, and merely argued for caution until the facts could be established. In the meantime, it ordered Galileo to refrain from challenging the theologians.

Specifically, Rowland identifies Galileo’s “mistake” as asserting “that there is a single and unique explanation to natural phenomena, which may be understood through observation and reason, and which makes all other explanations wrong.” On the contrary, Rowland avers:

"It is simply not correct … that there is a single and unique explanation to natural phenomena…. Scientific ‘facts’ … are not literal representations of nature, but analogies, metaphors, simulacra. The truth that science ‘discovers’ is not objective and immutable, it is subjective and socially contingent.”

Here Rowland is clearly referencing Thomas Kuhn’s seminal work, The Structure of Scientific Revolutions. [There are very few footnotes, however, and none on this particular work, but the allusion is obvious.] While Kuhn’s argument has merit, it doesn’t seem exactly applicable to the battle between the Church and science.

In addition, Rowland presumes that religion is [also] in some way "true," but never cites a single true statement coming from a religious or Scriptural source. He takes for granted that God exists and is infinitely powerful, and that therefore God is not bound by scientific laws. Thus, he concludes, Galileo was mistaken in asserting the primacy of reason informed by observation.

In current times, we are more willing to accept that there is not necessarily a universal standard of truth. But even in the Sixteenth Century, a dichotomous conclusion would not have been necessary, albeit for different reasons. By the time Galileo lived, the Church was well acquainted with the work of Maimonides, especially because of his influence on St. Thomas Aquinas. Maimonides argued that the “divine wisdom” inherent in nature is in fact the most substantive revelation of divinity. Such an approach would be one that would allow for both Galileo and the Church to abide in harmony. [Although Maimonides also had views that would have been anathema to the Church, such as the rejection of all forms of theurgy (the operation or effect of a supernatural or divine agency in human affairs).] But the point is, that epistemological development at the time Galileo lived could have supported an acceptance of different ways of knowing the truth, and of appreciating God.

While I can hardly claim to be an expert myself, I was deeply influenced by Ernan McMullin at the University of Notre Dame. He was not merely a delightful philosopher, physicist, and Catholic priest; he was a well-recognized authority on Galileo. Professor McMullin defended some of the actions of the Church (though not as vigorously as Rowland), but he felt that even though Galileo overreached a bit in his scientific conclusions, he was a better theologian than the priests opposing him.

Evaluation: Although I am more critical than Rowland of the Church’s actions in the Galileo affair, his book provides important nuance to understanding a monumental chapter in the history of science and religion.

(JAB) ( )