Sunday, November 21, 2010

Revisiting Galileo's Heresy

The climate change dialogue over the past thirty years has teetered from calls for bold action to deal with global cooling and then toward calls for bold action to deal with global warming with seemingly incontrovertible scientific influence. The debate, taken in its entirety, brings to mind the late great controversy involving the venerable Galileo Galilei who made scientific and political waves of his own in the early 17th century.

We remember that Galileo advocated – and was consequently excommunicated for advocating – heliocentricism (the theory that the Sun is at the center of the universe), a theory that was considered contrary to Scripture and Church teachings. That is what most of us were taught about Galileo’s heresy, but there is a little more to it than that. In truth, heliocentricism was actually nothing new in Galileo’s time. The ancient Indians and Greeks advanced the early heliocentric model, while Ptolemy, Aristotle, and others held a geocentric theory (that the Earth is at the center of the universe). Copernicus came along at the turn of the 16th century and breathed new life into the heliocentric theory and Galileo picked it up a century later. So, if heliocentricism was nothing new, why did it get Galileo into so much hot water?

Well, science was a bit different in those days than we expect it to be today. While we expect science today to pursue and define the true nature of things and support those findings with undeniable proof, that was not the work of science in Galileo’s day, dating as far back as Aristotle. Before Copernicus and Galileo, science focused on developing hypotheses that based their legitimacy on the extent to which they merely corresponded to or were consistent with known observations of reality – whether they “saved the appearances” – rather than whether they actually equated to the truth.

Galileo owed the early trouble he had with the Church not so much to his support of heliocentricism but to the fact that in asserting that heliocentricism not only saved the appearances but that it was also reality, he put the Church in the middle of a change in the very nature of scientific hypothesis formulation, a change from science as merely “saving the appearances” to science as the pursuit of the truth. The problem for the Church was that it intended to remain neutral on the issue of science, fully comfortable with science that saved the appearances. The Church had been largely indifferent to astronomy; in fact, it considered astronomy and mathematics to be theologically irrelevant. As St. Ambrose wrote, “To discuss the nature and position of the earth does not help us in our hope of life to come.” But Galileo went at the Church aggressively, insisting that it not only accept Copernican heliocentricism as truth, but that it also either renounce Scripture that implied otherwise or change its teachings to conform to this new “truth.”

When the Church tried to avoid a confrontation on the issue by asserting its neutrality on science, Galileo argued that if Scripture was indifferent to science and did not assert a geocentric premise and maintain that the Sun did not move, it would not have taught that Joshua commanded the Sun to stand still in Joshua 10:12. Then there was Psalm 93:1, Psalm 96:10, and 1 Chronicles 16:30, “…the world is firmly established, it cannot be moved,” Psalm 104:5 “…the Lord set the earth on its foundations; it can never be moved,” and Ecclesiastes 1:5 “…the Sun rises and the Sun sets, and hurries back to where it rises.” While the Church might have preferred that science maintain its focus on saving the appearances and that the Church not have a role in science, Galileo had stirred up a massive political hornet’s nest that thrust science into theology, a course of events that neither party could or would remove itself from once it began.

So, the Church put the ball back into Galileo’s court. If science was going to progress beyond merely saving the appearances and assert certain findings as fact, it would have to follow through with proof of its findings. The Church indicated that it was willing to revisit teachings that implied support of bad science, but not until it had proof to justify the change – too much was at stake. Cardinal Robert Bellarmine, as Consultor of the Holy Office and Master of Controversial Questions during the Reformation, wrote a letter that encapsulated the Church’s position on Copernicanism. He wrote that Copernicanism was an acceptable working hypothesis and that if there were real proof that the earth circled the Sun, “then we should have to proceed with great circumspection in explaining passages of Scripture which appear to teach the contrary…” It amounted to a “put up or shut up” position to Galileo; the Church was willing to revisit its teachings, but Galileo needed to either prove the theory or stop pestering the Church about what he loudly proclaimed were false teachings.

Proving heliocentricism was the challenge. Even before Galileo’s time, opposition to the heliocentric theory in the scientific community was well established. Nineteen hundred years before Galileo, Aristotle argued that if the earth did, in fact, orbit around the Sun, one should be able to observe a shift in the position of a star seen from the Earth on one side of the Sun one day and on the other side of the Sun six months later, a phenomenon known as stellar parallax. Galileo was unable to counter this ancient objection. In explaining how the planetary orbits he claimed worked, Galileo maintained that the planets revolved around the Sun in perfect circles while astronomers at the time could clearly discern that they did not.

He also attempted to explain that the tides were caused by the Earth’s movements, dismissing Kepler’s theory – his correct theory – that the Moon caused the tides. The lack of supporting evidence and a foundation of errant premises cast grave doubt on his conclusions and thus, he was not able to provide a basis in science for changing the prevailing thought on the movement of the heavenly bodies. In spite of that, Galileo persisted in his loud attacks against the Church on the subject. Ultimately, the Church excommunicated him after a laborious effort to persuade him to either produce proof or lower the noise level until he did.

So, Galileo’s heresy wasn’t that he disagreed with the Church or that he advocated a radical bit of science that opposed the thinking at the time; his heresy was that he loudly asserted that Church teachings were wrong and demanded that the Church renounce Biblical passages, even without presenting scientific proof to support his claims. He wanted to thus radically change the culture of the Church and of science in one fell swoop through the acceptance of his hypothesis as fact, the ramifications of which no one knew, and he wanted this change on the basis of proof that amounted to little more than the old “saving the appearances” brand of science that commanded no such influence.

In the short 400 years since Galileo, what we have of the lesson of his excommunication is the fashionable condemnation of the Church in the belief that Galileo was correct in his science while the Church was wrong in its dogma. This is a vast over-simplification that obscures the real lesson of Galileo’s heresy. The lesson should have been that it is no longer good enough in modern science to “save the appearances” while savaging weak minds and winning political points through the demagogic exploitation of public ignorance and popular fears. We should have learned that the essence of Galileo’s heresy was in his insistence that the Church, the scientific community, and society in general undergo radical cultural changes without the benefit of scientific proof to justify it. We should have learned that the eminence of science in this new age demands that it function above the political fray, and not be distracted from its dogged determination to establish its legitimacy with proof, not politics and consensus.

From those lessons, we might have been left with a faithful discernment between what constitutes social activism and what constitutes science. We might have been wary of science that takes its authority from a consensus rather than from the scientific method. We might have been sophisticated enough to resist the vacillations of political and social tides by binding theorists and activists to a burden of proof that is indifferent to institutional edicts and public opinion. We might have found as much heresy in the global cooling scare as we find in the global warming scare of today, the “heresy” being the expectation of activists to have us accept unproven positions as science and fact. Building a hypothesis on the basis of a century’s worth of temperature change and a photograph of a polar bear floating on an iceberg is a splendid example of saving the appearances, but it falls well short of scientific proof. The absence of proof in the face such political fervor invites doubt on the aspects of the global warming argument that might actually be valid.

For as much truth as there ultimately was in Copernican heliocentricism, there was at least as much wrong with Galileo’s “proof” that the theory was valid. His assertion that the Sun was at the center of the universe was true, but many of his proofs and supporting theories were not. The lack of sound science in his day kept the world in the dark on the validity of the heliocentric theory for 150 years after Galileo proclaimed it, and Galileo shares the blame for it by infusing science into politics and theology rather than elevating it with proof. We should be concerned that loud noise and political bluster in the face of a lack of sound and complete science today might again keep the world in the dark on the validity of important and influential theories relating to global climate change as well.

There might be a morsel of truth here and there that might be of great value in contributing to the broader scientific study of the issue. As a premise for action, though, we need more science on the fundamental issue and a better understanding of the deep implications of action – and of inaction – on our economy, our human evolution, and our politics. Without sound science to compel a focused and essential call to action, we’re doomed to repeat Galileo’s heresy, but with potentially more severe consequences. At this point, we don’t need more politics; we need better and more complete science.