Galileo and the Church, Part II

In 1543 the publication of Copernicus On the Revolutions of the Heavenly Spheres led to a revival of the idea of heliocentricism. Over the next 40 years the theory began gaining ground in spite of warnings from theologians that its assumptions were counter to scripture. By 1600, Galileo (then only thirty six years old) was convinced that the heliocentric model must be correct, even writing to Kepler in Prague, “Like you, I accepted the Copernician position several years ago and discovered from thence the causes of many natural effects which are doubtless inexplicable by the current theories.” By 1610, Galileo had become even more convinced when he became the first person to observe four moons revolving around Jupiter, and in 1611 he observed sunspots, concluding that they could only be explained if it was hypothesized that the sun revolved on an axis.

In the meantime, opposition to heliocentricism was growing in Rome following the burning of declared heretic Giordano Bruno who, among other dissenting beliefs, held the heliocentric view openly. Bruno’s trial and execution was overseen by the harsh inquisitor Cardinal Robert Bellarmine who refused to allow Bruno to partially recant his ideas. But Bellarmine was a man of great intelligence, open to scientific arguments. When he heard of Galileo’s discoveries concerning sunspots and the moons of Jupiter, he asks Jesuit mathematicians to confirm the scientists’ observations. They did so, but argued that the observations aren’t clear evidence for the motion of the earth. By 1613 arguments began to appear that explicitly condemned the Copernician theory.

By then Galileo is in residence in Rome, teaching at the Accademia dei Lincei and it is at this time that he makes a crucial decision. Or perhaps there wasn’t much of a decision to make. Galileo was a devout Catholic who took his allegiance to the church seriously. But he was also a scientist unwilling to compromise his intellectual honesty. In 1613 he wrote a letter to a professor at the University of Pisa offering his thoughts on how the heliocentric model and the integrity of Scripture could both be maintained, writing that the Holy Scriptures “…like nature, owe their origin to the Divine Word….It was necessary, however, in Holy Scripture, in order to accommodate itself to the understanding of the majority, to say many things which apparently differ from the precise meaning. Nature, on the contrary, is inexorable and unchangeable, and cares not whether her hidden causes and modes of working are intelligible to the human understanding or not, and never deviates on that account from her prescribed laws.”

Two years later the letter was used in a complaint reporting Galileo to the Roman Inquisition. In response, Bellarmine issued a caution for scientists to treat Copernicus’ views as unconfirmable hypotheses rather than fact. Galileo went to Rome to defend his views, writing a paper arguing that tidal motion proves that the earth revolves. Advisors to the Inquisition responded with an official declaration that the concept of a moving earth is ridiculous and formally heretical. Bellarmine admonished Galileo in 1616 not to hold the Copernician view (there is some debate about whether he was ordered not to teach the view at this point). Galileo agreed to accept heliocentricism only as a logically possibly hypothesis. That same year Copernicus’ famous text was banned by the Inquisition. That same month, Galileo met with Pope Paul V.

And then things went sort of quiet for a while. Galileo continued to teach and publish interesting papers on comets and sunspots supporting the Copernician view, but being careful to temper his explicit arguments. In 1623, Galileo saw hope in the ascension of the fair-minded Cardinal Baberini (who had opposed his admonition in 1616) as Pope Urbana VIII. He met with the pope and other cardinals six times to explain Copernican theory. Interested in the ideas, the Pope assured Galileo that he had nothing to fear in discussing Copernican theory so long as he treated it as a supposition and not an established fact. The Pope also granted Galileo’s request to write a book comparing the geocentric and heliocentric views openly and fairly. He completed the book in 1630 and went through all the necessary channels to get approval from the Vatican for its publication. In 1632 it was printed. Four months later the pope ordered its distribution stopped and ordered a special commission to examine the book. Based on the commission’s report, the pope referred Galileo’s case to the Inquisition.

So what had happened? The problem was Galileo’s inability to contain his theoretical bias as well as some personal pride on the part of the pope. The book Galileo had published, Dialogue Concerning the Two Chief World Systems, was formatted as an Aristotelian dialogue between two learned men, one of whom held the heliocentric view and the other the geocentric view. Unfortunately, in a few passages the man holding the latter view seemed to be portrayed as foolishly holding to his beliefs despite clear evidence to the contrary. In his depositions before the Inquisition, Galileo claimed this was completely unintentional, stating “with the said book I had neither held nor defended the opinion of the earth’s motion and sun’s stability; on the contrary, in the said book I show the contrary of Copernicus’s opinion and show that Copernicus’s reasons are invalid and inconclusive.” But it seems Galileo’s theoretical bias had slipped through. At his second deposition two weeks later, he had gone back and reread his own book which he claimed not to have read since he had written it three years before, stating that “I wanted to check very carefully whether, against my purest intention, through my oversight, there might have fallen from my pen not only something enabling readers or superiors to infer a defect of disobedience on my part, but also other details through which one might think of me as a transgressor of the orders of Holy Church.” His conclusion was a free confession that at some parts he could indeed see how someone might get the idea he was arguing for one side over the other rather than presented both views as valid, “in particular, two arguments, one based on sunspots and the other on the tides, are presented favorably to the reader as being strong and powerful, more than would seem proper for someone who deemed them to be inconclusive and wanted to confute them, as indeed I inwardly and truly did and do hold them to be inconclusive and refutable.” Galileo offered to write another book that would correct these misperceptions in Dialogues, an offer which was refused. Perhaps more damning, however, was the perception by the Pope that Galileo had placed the pope’s very words into the mouth of his geocentric-leaning literary character. The Pope therefore felt personally slighted by the passages which made this character appear as a fool. Whether this was intentional or a misperception on the pope’s part was isn’t known and wasn’t addressed in the depositions.

At his final deposition, Galileo was finally asked whether he held the Copernician view. He denied that he did, but claimed to hold the Ptolemaic geocentric view. He was asked repeatedly and under threat of torture to tell the truth. He repeated only that he did hold the Ptolemaic view and had held it since the injunction from Cardinal Bellarmine was issued against him. In the end, Galileo received a papal condemnation sentencing him to prison for an indefinite term (he was 70 years old at the time). After signing a formal recantation, he was allowed to serve his term under house-arrest where published the foundational Two New Sciences (despite the papal ban on his publishing anything). He died eight years later.

What exactly was Galileo’s crime? Was it really that he held and taught and wrote about the heliocentric view? It is doubtful since as I wrote before, the heliocentric view was quite commonly known amongst the public and even quite commonly believed in academic circles. In the next and final post, I’ll make the case that Galileo’s crime was not his scientific belief, but rather the fact that he challenged the church’s official interpretation of Scripture. I’ll also draw modern parallels, suggesting that Galileo’s experience can help us out of the quagmire between science and religion we are experiencing today.