Defending Copernicus and Galileo: Critical Reasoning in the Two Affairs (review)

Why yet another book on the so-called Galileo Affair in view of the extensive literature already available? This question is further exacerbated by the fact that this work provides no new historical data. However, the merit of this work is that it approaches the whole affair by attempting to offer a defense of Galileo by employing the same critical reasoning that Galileo himself used in defending Copernicus. Much of the book is, in fact, a study in the epistemology of critical reasoning in science, and it makes an important contribution to the very meaning of science by studying the origins of modern science in Galileo's research techniques. The author uses this overarching theme of critical reasoning to offer a synthesis of his numerous previous publications on the Galileo Affair. In so doing, however, the treatment becomes unduly repetitious, and this makes for difficult reading. In fact, the author reveals that this work is a collection of previously published papers. It would have been a much more readable book had there been more careful editing to weave the previous publications together into a more unified presentation.

Chapters 1 and 2 essentially cover material that is available in general astronomy textbooks, and it could have been presented here much more succinctly. By far, one of the best presentations in this book is section 4.5, where the author treats of Galileo's letter to the Grand Duchess Christina Medici on the interpretation of scripture. His analysis is thorough, concise, and convincing. He correctly identifies the central argument of Galileo in his letter that, although we may accept that scripture cannot err, one may clearly err in the interpretation of scripture. The author then provides an excellent discussion of Galileo's views on the various ways in which scripture may be interpreted. Galileo concludes, according to the author, that in no place does scripture teach scientific facts and, therefore, cannot contradict science. He persuasively concludes that, of the many reasons adduced for the condemnation of Copernicanism in 1616, the main one was that church authorities, inspired principally by the thinking of Jesuit saint and cardinal Robert Bellarmine, were convinced that Copernicanism contradicted scripture. These were the years of the Counter-Reformation. It had only been about seventy years since the Catholic Church had solemnly declared at the Council of Trent that scripture could not be interpreted privately. The author correctly maintains that, in Galileo's letter to Medici, he had offered a correct interpretation of scripture, but he had done so privately. In fact, in very general terms Galileo's approach to scriptural interpretation was embraced officially by the Church about four centuries later.

In 1616, at the desire of Pope Paul V, Bellarmine admonished Galileo that he was not to pursue any defense of Copernicanism because it contradicted scripture. In reality, it did not. In 1633 Galileo was condemned for disobeying that admonition that was based on a false premise. The author correctly describes this as one of the greatest ironies in the history of the interaction between science and religion. On the one hand, we have the presentation by Galileo of some of the best arguments ever advanced as to why a particular scientific theory was compatible with scripture and why in general scripture is not a scientific authority. On the other hand, one of the world's great religions formally condemned a key scientific theory that played a crucial role in the rise of modern science. The struggle to maintain a healthy interaction between modern science and religious belief—in particular, beliefs based on scripture—has not ended, and we have much to learn from the critical reasoning with which this book studies anew the Galileo Affair.

One of most useful features of this book is the bibliography on pages 315-38, which, although titled "Selected Bibliography," is, in fact...