Richard Blackwell is already well known to Galileo scholars for his previous books: Galileo, Bellarmine, and the Bible (Notre Dame, Ind.: University of Notre Dame, 1991) and A Defense of Galileo, a Mathematician from Florence (the English translation of Campanella's Apologia pro Galileo, [Notre Dame, Ind.: University of Notre Dame, 1994]). His new book is another worthwhile addition to the Galileo literature. In the four chapters of its first part, Blackwell offers a reconstruction of the various events behind the scenes of Galileo's trial and condemnation (April–June 1633) and of the role played in it by two important dramatis personae (the Jesuits, Melchior Inchofer and Christoph Scheiner). This is followed by a final reflection on the meaning of the trial in light of the present-day religion and science debate. The second part of the book contains the first English translation of the Tractatus syllepticus of Inchofer (a theological vindication of Galileo's condemnation), and of the first chapter of Christoph Scheiner's Prodromus pro Sole mobile (its scientific vindication), as well as the translation of several official documents of the Society of Jesus enforcing on members of the order a strict fidelity to Aristotelian philosophy.

The first chapter, “The Legal Case at Galileo's Trial: Impasse and Perfidy,” deals chiefly with two pivotal moments in the Galileo trial. The first is the extrajudicial initiative taken by the Commissary of the Holy Office, the Dominican Maculano, in an effort to overcome the impasse created by Galileo's refusal, in the first interrogation, to admit any wrongdoing in writing his Dialogue on the Two Chief World Systems. Shortly after, an examination of the Dialogue by an appointed commission of three theological experts (among them the Jesuit Inchofer) concluded that in his book Galileo had in fact taught and defended the Copernican thesis and was “vehemently suspect” of holding it, thus indicating a serious lack of sincerity on his part. What was Maculano to do?

To avoid a “rigorous examination” (including the threat of torture) in order to ascertain Galileo's true intentions, Maculano obtained the approval of the cardinals of the Holy Office for an extrajudicial procedure by which he hoped to bring about, by persuasion alone, an acceptable confession on the part of the scientist. Galileo scholars are divided as to what may have been intended through this initiative. Blackwell proposes to interpret it as what would today be termed a “plea bargain,” by which, in exchange for a confession of wrongdoing in writing the Dialogue, Galileo would obtain a milder punishment than the one reserved for “vehement suspicion of heresy,” the charge that was implied in the commission's conclusion. Since the trial ended in an affirmation of the commission's charge, with the consequent punishment, Blackwell argues that this implies a violation of Maculano's promise, in effect, “perfidy” on the part of the Holy Office.

But all kinds of questions arise: Do we really know what the terms of the initiative were? Do we know that Galileo actually agreed to them? If there was an agreement, did it constitute a juridically binding bargain, as the strong term “perfidy” suggests? In a letter to Cardinal Francesco Barberini (quoted by Blackwell), Maculano says that if his initiative succeeds, Galileo can be treated “with benignity” and the matter “may be settled without difficulty” and adds, “whatever the final outcome,” which hardly suggests a promise in regard to that outcome. But the principal difficulty Blackwell's very serious allegation faces is that in the interrogation that followed, Galileo did not, in fact, confess to having defended the Copernican thesis in the Dialogue; there was no “dramatic” change of attitude on his part, as Blackwell claims. So his part of the bargain (as Blackwell construes it) was not kept.

At some point before a final trial decision was reached on June 16, a summary of its antecedents and of the interrogations of Galileo was submitted to Pope Urban and the cardinals of the Holy Office on whom the decision rested. Blackwell argues that it was this summary that “sabotaged” Maculano's commitment to Galileo. The summary did indeed contain some serious misrepresentations of the facts, indicating a hostile attitude toward Galileo on the part of its author and perhaps a segment of the cardinal judges. So if these misrepresentations were indeed responsible for the negative turn that the trial took, this would be a further reason to cry foul.

However, the summary had also (correctly) reported the response of the theological consulters of the Holy Office in February 1616 on the two main theses of Copernicus. Claiming the sun to be at rest was described as false and absurd in “philosophy” (science) and formally heretical because it contradicted unambiguous scriptural texts. Claiming the earth to be in motion was also held to be false and absurd but assessed as at least erroneous in faith rather than formally heretical, since its immobility was not clearly stated in the Holy Scripture. The consulters' response had not previously been made known.

Earlier in his career, Urban VIII had intimated that in his view the decree of the Index in 1616 declaring the Copernican thesis to be “false and contrary to Scripture” meant that the thesis was “rash,” a lesser charge. It may well have been that learning from the summary of the much more serious charge that had been made by the consulters back in 1616 encouraged him now to adopt a more serious interpretation of the juridical force of the admittedly ambiguous decree of 1616. It may also have been his outrage over the manner in which Galileo had apparently set aside Urban's firmly stated theological objection to the unqualified assertion of the Copernican claims. On June 16, Galileo was charged with, and condemned on, “vehement” suspicion of heresy. Of course, we do not know (and most probably will never know) what other factors may also have motivated Urban to make this fateful doctrinal determination. However, the deep personal resentment for having been betrayed by his former friend, Galileo, by the publication of the Dialogue and the necessity of reasserting his authority in a very difficult political moment of his pontificate hint at some of these other causes. In the circumstances, claiming that “the plea bargain gone awry” was what “had come back to convict him” (26) is open to serious questioning.

The reader will find the chapters regarding the role played in the trial by Inchofer and Scheiner very illuminating. Inchofer's unequivocal condemnation of Copernicanism undoubtedly carried weight at the trial. In the Tractatus syllepticus, he defends his position in great detail, helpfully commented on here by Blackwell. Scheiner was torn between a criticism of Galileo's Dialogue based more on personal resentment than on hostility toward the Copernican thesis itself (a thesis which he perhaps secretly shared) and his intent to vindicate the freedom of scientific research against the fetters of fidelity to the Aristotelian natural philosophy, imposed on him by the authorities of the Jesuit Order.

In the chapter, “Fallibilism and Religion,” Blackwell offers some quite challenging personal reflections on the roots of the Galileo affair. In contrast with the openness of the medieval scholastics with regard to the Aristotelian worldview despite its conflicts with the biblical worldview, the Catholic Church in Galileo's time had become a highly centralized organism with a strong emphasis on the principle of divinely entrusted authority, conveying non-fallible truths. An undue enlargement of the field of those truths to include even issues—like the Copernican one—not pertaining to faith and morals, inevitably clashed with the newly born principle of the independence and authority of scientific research represented by Galileo's work. In its further historical development, the fallibility of science has been recognized as one of its distinguishing characteristics, and thus (according to Blackwell) the potential for conflict with an overly wide concept of religious infallibility is ever-present.