Saturday, February 20, 2010

Galileo's Trial: a battle between science and religion?

Post #1

The Standard Story

One of the most famous episodes in the history of science and religion is the Copernican Revolution, which began with the publication of Copernicus’s book in 1543 and culminated with the trial and conviction of Galileo in 1633. It did not end there, but that is as far as we will go in this series.

The standard story goes something like this: medieval Church doctrine held that the Earth was at the center of the universe, as it should be, since this is the most privileged location in the universe and Earth, being the home to mankind, is the most important planet. Copernicus and other scientists like Bruno and Galileo challenged this doctrine with scientific evidence showing that in fact the Sun was in the center. The Church, furious that scientific progress was being made (progress which challenged its own doctrines), persecuted these brave souls who dared give voice to reason and evidence. In short, this episode is an archetypal example of the conflict between science and religion.

I cannot recall how many PBS or Nova TV specials have been aired on the trial of Galileo, pitting Galileo the brave scientist against the oppressive anti-science Church. This version of the story is simply assumed by a great many people. For example, in an article for Slate magazine, Nathan Myhrvold wrote:

“Ptolemy (second century) was the first and boldest in a long succession of spin doctors for the primacy of human beings. The whole universe, he postulated, rotated around us, with the Earth sitting at the center of heaven itself. Any marketing consultant will tell you that positioning is everything, and center-of-the-universe is hard to beat. A Polish astronomer named Copernicus (1473-1543) rudely pointed out: Sorry earthlings, we spin around the sun, not vice versa…Bruno's crime, like Galileo's, was to undermine the uniqueness of our planet, and by doing so, to threaten the intellectual security of the religious dictatorships of his time. People get cranky when you burst their bubble. Over time, advances in astronomy have relentlessly reinforced the utter insignificance of Earth on a celestial scale. Fortunately, political and religious leaders stopped barbecuing astronomers for saying so…”

Slate magazine, a well-respected publication, is part of the Washington Post and has associations with National Public Radio. The standard story, however, as well as Mr. Myhrvold’s particular version of it, contains serious historical errors. Historian Richard J. Blackwell writes, “An oversimplified and false view is that Galileo became a martyr of science because of the Roman Catholic Church’s opposition to science, but it is now commonly agreed that the facts are quite otherwise.”

This will be the first in a series of posts intended to correct this common, but false, view of the Copernican Revolution.

Geocentrism and Greek Philosophy

The first myth we will tackle is the idea that geocentrism (the belief that Earth was at the center of the universe and everything revolved around it) was a Christian doctrine that entailed believing the Earth was special. In fact, geocentrism was an idea from Greek philosophy, not the Church. The Greeks devoted a lot of time to pondering the nature and structure of the universe, or cosmology. The geocentric theory was developed according to reason, evidence, and philosophical principles, not religious dogma or a special view of humanity. The geocentric model of the universe inherited by the medieval Church was the culmination of careful Greek thought, with Aristotle supplying the metaphysics and Ptolemy the mathematics. Ptolemy’s geocentric model was a masterpiece that matched up very well with astronomical observations. This model was adopted by Church scholars as well as by practically all the natural philosophers (i.e. scientists) of the time.

The geocentric view did not entail thinking the Earth was special. When Mr. Myhrvold, quoted above, asserted that the Earth was thought to be “at the center of heaven itself,” he could not have been more wrong (though at least he acknowledged the Greek origins of geocentrism). Within Aristotelian cosmology, Earth was thought of as corrupt and base, while the heavens were perfect and, well, heavenly. A more accurate description of Earth’s status at the time is that it was seen as the garbage dump at the bottom of the universe. Things were thought to fall to Earth because they were “heavy” and corrupt, and the Earth was the designated place for such unworthy things to fall. Indeed, Galileo saw his own work as elevating the status of Earth, not demoting it, writing:

“For I will prove that the earth does have motion, that it surpasses the moon in brightness, and that it is not the sump where the universe’s filth and ephemera collect.”

Next post: The Copernican Revolution

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