Thursday, September 21, 2006

The Galileo Caper

Most institutions demand unqualified faith; but the institution of science makes skepticism a virtue. ~Robert K. Merton

I'm sure you were relieved to learn that Pope Benedict XVI is holding a "private seminar"at the Vatican to assess the Church's position concerning Darwinian evolution. Now, given that John Paul II stated in 1996 that evolution was more than a hypothesis, you'd think there would be a sufficient precedent to go on, but evidently Benedict wants to come up with something more definitive.

Rather brings to mind the Galileo caper.

It is a mistake to assume that the Church refused to accept scientific progress. What was important to the authorities was to control the release of new science with the Church's approval and, more importantly, the Church's interpretation relative to Catholic dogma. However, Rome was also wedded to Aristotelean science; any theories that went beyond that had to be treated with care. One such theory that definitely went beyond was the Copernican view of the solar system.

Copernicus himself was in no hurry to publish his work, knowing full well that it was running against the grain of centuries of belief in an Earth-centered universe. He knew that he wasn't answering some important questions, basically because there was still a lot to learn. For example, one significant objection to his theory was the fact that, if the planets circled the sun, why didn't they fall into it? However, an aged Copernicus finally agreed to publish his work, which didn't happen until after his death, in 1543. Even so, it contained a preface, written by a professor named Rheticus (who oversaw the publication) which added the disclaimer that the book should not be taken as a theory of how the universe actually worked, but as a mathematical construct that conveniently fitted the natural world.

About seventy years later, Galileo Galilei started looking through his telescope and began confirming the Copernican system. He listed his discoveries in a book called The Starry Messenger, but he wisely avoided any direct statement that these observations supported Copernicus. Galileo was no dummy; he preferred to work with the Church to get official sanction for his work, an excellent alternative to being burned as a heretic. So he visited Rome in 1611 where he was positively received by Pope Paul V. He presented his work to a committee of Jesuits (a very tough crowd) which concluded that:
  1. the Milky Way consists of a huge number of stars,
  2. Saturn had an oval shape that looked as though there were object on either side,
  3. the Moon surface is scarred and pitted by craters,
  4. Venus has phases like the Moon,
  5. Jupiter has objects circling it.
The Church put its imprimatur on Galileo's observations but stopped short of making any comment approving the Copernican system.

So, at this point, Galileo is in good with the Vatican. What went wrong?

Feeling confident in his relationship with Paul V and Cardinal Bellarmine (the power behind the papacy), Galileo began to be more open about supporting the sun-centered universe. Eventually, he was back in Rome, this time in front of a group of Inquisitors. Bellarmine tried to broker a compromise (there is confusion over exactly what happened) that ended with the Inquisitors creating a set of "minutes" for the official record that held that Galileo could not "hold, defend, or teach" the Copernican theory. However, Bellarmine and Paul V made sure it was clear that Galileo had done nothing wrong; he had only been informed of what was a general edict from the Catholic Church.

By 1624, there was a new pope, Urban VIII (there was another in between, but he doesn't matter to the story). Once again, Galileo, who had published a book on comets, came visiting and hit it off with the new pope. As a result of the meetings, Urban VIII granted Galileo permission to write a book about both the Ptolomeic and the Copernican systems, so long as he simply described them but did not argue in favor of the Copernican view.

The book, Dialogue on the Two Chief World Systems, was set as a dialog between two characters and a moderator. A character called Salviati supported the Copernican idea, while Simplicio (remember that name) presented the Ptolomeic system. Sagredo was the supposedly impartial moderator, and therein lay the problem. As the book progresses, Sagredo begins more and more to support Salvati over Simplicio.

Despite this, things seemed to be going well for Galileo. It was passed by a Catholic censor with only a request for an introduction and conclusion explaining that the Copernican theory was presented only hypothetically. The censor sent along suggested text, with the comment that Galileo could revise it as long as the meaning was not changed. Galileo made one small addition, which clearly indicated that the preface and conclusion did not represent his own views.

Then it was noticed that Simplicio was using verbiage that was close to wording used by Urban VIII. Now, the name Simplicio can be taken to indicate a simpleton, and his presentation in the dialog, coupled with Sagredo's support of Salvati, could be taken to mean that Galileo was implying that the Pope was a simpleton. Not a smart move.

So back to Rome came Galileo, and this time the welcome was not warm. The Inquisitors dug out the old minutes and accused Galileo of breaking its instructions. Cardinal Barberini, Urban's nephew, was still a supporter of Galileo and worked to mitigate any punishment, which ended up being house arrest. Legend says that, as Galileo left the Inquisitors, he mumbled, "Eppur, si muove" (yet, it does move). No one knows for sure whether he did, and if he had been heard saying it, he probably would have suffered torture or burning at the stake. Galileo was a stubborn, impatient, and contentious man all his life, but it's unlikely he was that stupid.

It's possible that had Galileo played by the rules, he could have publicized the Copernican system without ending up before the Inquisition. The Church was ultimately left with its Aristotelean framework while the rest of the world moved on. Eventually, hundreds of years later, the Vatican would admit that it was wrong in condemning Galileo, as if the rest of the world, including all Catholics, hadn't figured that out already.

If Benedict's Star Chamber session on evolution doesn't keep history in view, we're going to need another admission of error somewhere down the line. Maybe in a few hundred years, give or take a few decades.

Reference: The Scientists by John Gribbin (Random House, 2002).

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