The Investigation and the Trial

Following the report of the special committee, the Pope transferred the investigation of the affair into the hands of the Inquisition. At this stage, the Tuscan Duchy attempted to intervene and bring the affair to a close, through diplomatic contacts with the Church. Galileo had been the Tuscan court philosopher for more than twenty years, and was the protege of the Grand Duke of Medici, to whom he had dedicated the Dialogue. Moves against Galileo were, in effect, moves against the Duchy. Throughout the autumn of 1623, the possibility of conducting the trial in Florence instead of Rome was discussed, yet despite the Tuscan efforts and the medical opinion regarding the deteriorating health of the 69 year-old Galileo, the Church insisted on Galileo's coming to Rome. The Pope, a past patron of Galileo, took his activities as a personal affront and refused to make things easier for him. In January 1633, Galileo left Florence and arrived in Rome two weeks later, where he found lodging at the Tuscan ambassador's home rather than the Inquisition house of detention. He was, however, placed under house arrest. On April 12, he was taken for his first official interrogation.

During this interrogation Galileo responded to the most serious claim leveled against him. Against the unsigned document which claimed that Cardinal Bellarmine forbade him to teach the Copernican theory, he presented Bellarmine's signed certificate. In this document, Bellarmine certifies that Galileo knows about the general prohibition, and does not mention the prohibition on teaching the theory. Against the other accusations, he continued to claim that in the Dialogue he did not wish to uphold or defend the heliocentric theory. Galileo's response surprised the inquisitors, who were not acquainted with the Bellarmine certificate. After the initial investigation, there was another break in the proceedings. The Inquisition conducted negotiations out-of-court, similar to our present day "plea bargain." Galileo was accused in the slighter transgression, that of defending the Copernican theory contrary to the explicit Church verdict.

The Dialogue was given to three different consultants, who were charged with examining if it subscribed to or defended the theory that the earth moves. All three claimed that the book defends the theory and is also close to subscribing to it (an opinion accepted by most historians also today). Equipped with these expert opinions, the representatives of the Inquisition now turned to Galileo, demanding that he admit this guilt. A number of days later, on April 30, Galileo reappeared before his inquisitors and admitted his guilt. He declared that after three years, he had once again read his own book and had been surprised to find that it defended the theory stating that the earth moves, although this had not been his intention. Galileo explained that he had defended the theory because of his arrogance and his attempt to write the Dialogue in the most convincing way possible, by upholding the erroneous claims. Thus, out of his literary arrogance and his love for his own creation, he had sinned in defending the Copernican theory, and he now repented and asked forgiveness.

After this declaration, Galileo was taken for an additional interrogation, during which he was asked about his intentions when writing the Dialogue, and whether he upheld the theory (banned in 1616) according to which the sun is stationary and the earth revolves around it. Galileo responded to these questions by saying that he had not subscribed to the Copernican theory and his intentions were pure. The decision in this trial was so sensitive that it required the Pope's authorization. Urban XIII suspected Galileo's motives and demanded that he be interrogated again, this time under the threat of torture - an accepted Inquisition practice. Galileo repeated his version in this interrogation. In addition, the Pope also demanded that Galileo publicly recant the heliocentric theory and that the Dialogue be banned - even after it was made clear that Galileo's motives were pure (from an Episcopal point of view), and he had not attempted to defend the Copernican theory.