Galileo

Chances are you have been taught some of the same things I was taught in history or even perhaps science class about why the Roman Catholic Church had Galileo arrested. The myth goes something like this: Galileo was imprisoned or somehow tortured by the Church for advocating Copernicanism, that model of the universe that was relatively new at his time, firmly establishing the church's eternal enemy of science.

The Galileo affair is and has been until recent generations of a profession of historians of science today have come to a much better understanding of Galileo than you might have found 50 or 100 years ago. The story is often told that Galileo was some type of champion of free thought and some kind of point man for the scientific community, who turns his telescope to heaven and sees error reputable evidence somehow that proves the earth moves and the sun stands still. And the Church, ruffled by this for fear it contradicts their cherished understanding of Scripture, does all it can to silence him, including threatening him with jail or torture or, in fact, putting him in jail and torturing him. The truth really couldn't be further from this.

First of all, Galileo thought he had this positive evidence of the earth's motion and proof of the Copernican Hypothesis, but his evidence was faulty. He grounded most of his confidence in a theory he had about the tides. Although he thought it was a good theory, it turns out that it really wasn't a good theory. He did have interesting telescopical observations, but the telescopical observations themselves stop short of demonstrating that the earth moved. They certainly showed problems with one of the leading competitive theories of Claudius Ptolemaeus, the second-century astronomer. But Galileo overstated his case. He did so in a context where he alienated himself not so much from the Church as from the leading natural philosophers as we would call scientists in those days. Many of them had independent arguments with Galileo over the behavior of falling bodies, floating bodies in the water, sun spots, and how to interpret a supernova, and in case after case, Galileo was at odds with many of the leaders of the scientific community. When they found themselves frustrated by his virtuosity in these arguments, they began to involve the Church and challenge his robust claims to the motion of the earth.

Leaders of the Church were certainly open to the prospect that the earth might move, but they wanted to see good evidence. One of the most important leading figures, Cardinal Robert Bellarmine was pretty clear; he said, "if there was a true demonstration that the sun is at the center of the world, I like to see that demonstration. But I can't believe there is such a demonstration until someone shows it to me." He was not persuaded by what Galileo had to show him about the tides.

So Galileo kind of dug himself into a hole and did so even further when he was enjoined not to teach or publically discuss this idea of the earth's motion, and instead, he went ahead and wrote his dialog on The Two Cheif World Systems, which he published in 1632. It was a dialog between generally three figures, and in the mouth of the fool, he put the words of the Pope. When it was pointed out to the Pope that Galileo was actually taking this opportunity to what appeared to be ridiculing the Pope, Galileo was summoned to Rome and put on trial.

Ultimately, he was found vehemently suspected of heresy; in other words, he was never officially charged as a heretic but was placed under house arrest in his comfortable Italian villa for the remainder of his days which he continued scientific work. So the story is much more interesting than the narrow one that makes it look like the church was anti-intellect and bigoted. The point here is while he did have his opponents in his theory about the motion of heavenly bodies and the place of the sun and earth, these opponents were largely in the natural science communities and not within the Church itself.

-Dr. Mark Kalthoff