The Galileo affair flared around 1610, and consisted of a series of episodes which culminated in the condemnation of Galileo by the Roman catholic church in 1633. For his support of the Copernican heliocentric system, Cardinal Robert Bellarmine was called on to adjudicate their dispute. At the time, the prevailing system of the universe was a Ptolemaic geocentric one. Contrary to the Copernican system, the Ptolemaic one was thought to be compatible with the literal interpretation of some passages in the Bible. Galileo however, had challenged the Ptolemaic system by using evidence obtained by means of the observation of the planets, the sun, and the moon through the telescope, as well as other evidence based on the observation of natural phenomenon. The Galileo-Bellarmine dispute is often considered the quintessence of the battle between science and religion, or between reason and faith. Let's talk with experthistorian Renee Raphael, Assistant Professor of History at University of California, Irvine to learn more about the dispute. So, the Galileo-Bellarmine dispute is often considered a quintessential example of a battle between reason and faith. I would say as a historian of science that that's not a correct description of the conflict. So, if it were to be such a quintessential battle, we would assume that Galileo had all scientific reason on his side, and Bellarmine was only motivated by faith. But in fact, Bellarmine himself said that if there was sufficient what we would now call scientific evidence, he would be willing to change his interpretation of the Bible. But the reality was that in the period although Galileo had a lot of scientific reasons to suggest that the established model is incorrect, there was no scientific proof. Actual proof that we would say was definitive did not arrive until much later. So, for example, we didn't have any evidence of stellar parallax so that the earth was in motion until the 19th century. So, leading up to his condemnation, Galileo did not think that he was challenging the authority of the church. But theologians definitely thought that he was. So, I think that to understand the perceived conflict, one needs to look a little bit more at the historical context. So, in general, Galileo did not write about theology or the Bible. But as he became increasingly famous, theologians began to argue that the Copernican hypothesis that Galileo was advocating for was a threat to establish understandings of the Bible. Many historians have argued this was actually a conflict within the Church that some groups of theologians were upset with other groups that were on Galileo side. So, what Galileo ends up doing is he tries to address this through a very famous letter that he writes to the Grand Duchess Christina. In the text, he argues for an interpretation or an approach to interpreting the Bible and its relationship to science, that was well established from antiquity. The problem was that during this period, was a period in which the Catholic Church was combatting the Protestant Reformation. So, one of the edicts of the Catholic Church had been that only theologians in the Catholic Church had the authority to interpret the Bible. So, when Galileo went on to talk about how one should interpret the Bible, he was not a theologian. He hadn't been educated on theology. This was taken as Galileo overstepping his boundaries. So, Galileo was rehabilitated by the Catholic church only recently during the reign of Pope John Paul the Second. Historians have pointed to a number of reasons why this process took so long. Part of the reason was the Catholic Church should have continuing went back and revisited the Galileo affair coming to new conclusions, and the process a multi-step process by which initially Copernicus and the heliocentric doctrine was rehabilitated. This takes place over the course of the 18th and 19th centuries. Then finally, there is this official rehabilitation of Galileo. Historians have pointed to what happens in the 20th century is motivated a lot by events that were happening outside the Catholic Church. In particular, response to the Iranian Revolution and Pope John Paul the Second's desire to respond to the perception that religion led itself to fanaticism and to close mindedness. So, trying to look back at this affair and historians have argued that his response, and in two sets of speeches showed his acknowledgment that the church had wronged Galileo in their treatment of him, and that also that many of the principles that Galileo was advocating. For example, for the way that he argued for interpreting scripture, he actually had a more correct interpretation and more correct approach than those of the people who were opposing him in the period. The evidence available to Galileo was certainly less than decisive at the time. As historians of science have pointed out, observations through the telescope did not prove as such geocentrism wrong. Furthermore, although they run against the idea people had at the time of the heavens as being made of ether and not of matter, it was always possible to make further hypothesis. For instance, that the telescope was an imprecise instrument, and the seeming existence of mountains, and valleys, and some planets, and the moon was in effect a distortion of the instrument. Based on these considerations, epistemic relativists have often appeal to the Galileo affair to claim that the choice between a system of justification over another one is not grounded in objective facts, but depends on pragmatic factors. This does not mean that we could go back to the Ptolemaic system if we so wished. But the reasons why we can do so are only pragmatic. Galileo and Bellarmine disagreed about two non-fundamental epistemic principles. Namely, observation of the heavens and revelation of the heavens. In fact, they disagreed on whether the Bible had to be interpreted literally, and thus be taken as the ultimate source of evidence. Not just about religious matters, but also about empirical ones. This is not enough to justify a form of epistemic relativism however, which would usually be motivated by adherence to different and incompatible fundamental epistemic principles. In fact, empirical evidence piled up over time and even the church had to rehabilitate Galileo he found in 1992, by admitting that they were acting in good faith, It had been wrong. Contrary to what the late Richard Rorty maintain in the 80's then, we are not the heirs of just 300 years of rhetoric about the importance of distinguishing between religion and science. We're actually the heirs of over 300 years of patients scientific work, which has assembled evidence and develop theories that have proved geocentrism wrong.
