Behind the Scenes at Galileo's Trial (review)

With the Roman Inquisition, much happens behind the scenes. When Galileo appeared in Rome in 1633 to answer for the publication of his Dialogue on the Two Chief World Systems, the inquisitors must have thought it was a simple case of disobedience. The special commission they had charged with looking into the licensing of the book had discovered in the files a document claiming that in 1616 Galileo had personally been forbidden "to teach in any way whatever" the Copernican doctrine, which his book obviously did. Anticipating something of the sort, Galileo brought with him a letter from Cardinal Bellarmine expressly denying that he had been given any special injunction beyond the general decree of 1616 forbidding only the defending or holding of Copernicanism. Stymied by the contradiction between the two documents, the Commissary General Maculano da Firenzuola negotiated a plea bargain with Galileo, persuading him, according to Blackwell, to confess in exchange for some unknown lesser penalty. But someone very high up sabotaged the deal, Blackwell surmises, so when Galileo did confess to arguing too forcefully for Copernicanism, he was met with the full force of the law and sentenced to life imprisonment. But I think the plea bargain was not necessarily sabotaged: it was negotiated only after the special commission had been reconvened and reported that not only had Galileo taught Copernicanism (against only the doubtful special injunction), but also defended it and given cause for "vehement suspicion" that he held it to be true (against the general decree as well). The contradiction between the documents was thus moot — so, too, the misleading summary report, which Blackwell makes much of — and the case turned from simple disobedience to full-blown heresy. Maculano's plea bargain, then, was to persuade Galileo to confess to having given grounds for this vehement suspicion of heresy: otherwise, he could be condemned and perhaps executed as an obstinate and unconfessed heretic. So there was not necessarily any sabotage: quite the contrary, the plea bargain probably saved Galileo's life. What Galileo had thought was his best defence — the letter from Bellarmine — turned out to be his downfall.

The most damning report of that special commission was written by the Jesuit Melchior Inchofer. While the trial was still on, Inchofer then took it upon himself (Blackwell's arguments that he was commissioned or encouraged at the highest level are dubious) to show why Copernicanism was heretical. The Tractatus syllepticus (1633), a full English translation of which Blackwell includes as an appendix, sets out what Christians are to believe according to scripture concerning the motion and rest of the sun and the earth. In his analysis, Blackwell shows how Inchofer introduced a theological novelty by distinguishing "very probable" articles of faith from absolutely certain articles. While the motion of the sun is absolutely certain — since it is expressly stated in scripture and the truth of scripture is itself a certain article of faith — the stability of the earth is merely very probable, since it can be known only by inference from scripture. The Tractatus syllepticus should be read alongside the Letter to the Grand Duchess Christina (Galileo's ill-considered venture into scriptural interpretation) and Bellarmine's "Letter to Foscarini," both of which Inchofer seems to have drawn on, though it would have been useful if Blackwell had noted the parallels.

If Inchofer gave a scriptural defense of the decree against Copernicanism, the Jesuit astronomer Christopher Scheiner gave an astronomical defense. Because Jesuits had been required since 1613 to follow Aristotle in philosophy and Aquinas in theology, Scheiner, an expert observational astronomer, was caught between observational evidence and vows of obedience. Forced to write circumspectly, he thus became the butt of Galileo's unnecessarily violent attacks over the priority of the discovery and the nature of sunspots. The unkindest cut of all was that Galileo had appropriated Scheiner's discovery of variation in the angle of rotation...