Galileo’s Inquisition Trial Revisited (review)

The trial of Galileo continues to fascinate people, and this book is an attempt to assess the various interpretations that have been offered in recent years. The author raises a number of interesting questions about the way Galileo’s trial has been examined by scholars who often had a tacit agenda, be it to show that the Church is not infallible or to argue that it acted in a correct way given the nature of Galileo’s arguments and his inability to prove that the Earth really moves. Speller draws attention to the weakness of efforts to generalize from the very special, indeed unique, case of Galileo, and he is particularly sensitive to the context in which the trial arose. The book is well documented and often provides information that is essential to an understanding of the reasons why, for instance, Pope Urban VIII was so incensed when his argument about the nature of God’s creative power was presented by Galileo in a way that he considered inadequate. The matter is of course complex, but thanks to Speller we are better informed about the fact that the pope’s view, which is presented in the Dialogue on the Two Chief World Systems (1632), had already appeared in a work published by his personal theologian, Agostino Oreggi. The gist of Urban VIII’s argument is that God can create the world in an infinite number of ways and that speculation about matters that cannot be directly observed or experimentally verified is no threat to the traditional interpretation of the Bible. This philosophical position cannot be described as a novel one, for it was held by other thinkers at the time, but Galileo committed the gross error of putting it in the mouth of a philosopher, whom he called Simplicio, and who behaved like a simpleton during the four days that the Copernican system was discussed in the Dialogue. In 1616, sixteen years before he published his book, Galileo had been admonished not to teach that the Earth moves when the Holy Office was about to ban Copernicus’s On the Revolutions of the Celestial Spheres (1543). In 1623, Galileo had journeyed to Rome to meet Urban VIII shortly after his election, and he saw him on six occasions. We do not know whether the name of Copernicus cropped up in the conversation, but Galileo gathered that he was now at liberty to write about the heliocentric system provided he did not state clearly that he believed it was more than a working hypothesis. He did not inform the pope that he had been enjoined not to teach that the Earth moves, and his reasons for not doing this remain a moot question. The fact that the pope was a temporal as well as a spiritual leader frequently led to an intermingling of motives and motivations that we find difficult to disentangle. One thing is clear: Galileo overstated his case, and Urban VIII reacted with more rigor than we have come to consider appropriate. A less arrogant approach on Galileo’s part and a more genuinely spiritual outlook on the pope’s side would have led to a less dramatic outcome. But it is good to know that there has been only one Galileo trial. Perhaps history can teach us something after all.