The trial of Galileo Galilei, supporter of the Copernican-heliocentric theory on the motion of celestial bodies in opposition to the geocentric theory, supported by the Catholic Church, began in Rome on April 12, 1633 and ended on June 22, 1633 with the conviction for heresy with the forced renunciation of his astronomical conceptions. Galilei is interrogated for the entire month of January 1616 by the Holy Office; on 24 February 1616, the theologians of the Holy Office examined the two fundamental propositions of Copernicus’ De Revolutionibus, censoring them. The first, for which “Sol est centrum mundi, et omnino immobilis motu locale”, is defined as “foolish and absurd in philosophy and formally heretical”, since it contradicts the Holy Scriptures; the second, that “Terra non est centrum mundi nec immobilis, sed secundum se totam movetur, etiam motu diurnal”, for theologians is censurable in philosophy and at least erroneous in faith: “hanc propositionem recipere eandem censuram in philosophia; et spectando veritatem theologicam, ad minus esse in fide erroneam “.
On February 25, 1616, Cardinal Millini reports to the Congregation of the censorship of the two propositions; Pope Paul V orders Cardinal Bellarmine to admonish Galileo, in the presence of a Father Commissioner, to abandon the two propositions and not to teach, defend or treat them, under penalty of imprisonment: “non doctrinam et opinm docere aut defendere, seu de ea tractare; yes true non acquieverit, carceretur ». On September 28, 1632, the Holy Office issues the summons for the appearance of Galileo in Rome. He is interrogated again on April 30; he says he has reread his Dialogue and admits that the book appeared to him “almost as a novel writing by another author […] stretched out in such a form that the reader, unaware of my intrinsic, would have been right to form a concept that arguments brought to the false part, and which I intended to refute […] are really […] valued in the reader’s ear more than what seemed to be appropriate for someone who considered them inconclusive and wanted to refute them […] of having incurred in an error so alien to my intention that […] if I had to write now the same reasons, there is no doubt that I would enervate them in a way that they could not make an apparent display of that strength of which essentially and really they lack “.
He signs the report and is dismissed but shortly after he asks to return to the inquisitor to reiterate again that he has never supported “the damned opinion of the mobility of the earth” and that he is ready to rewrite a next book to show that he considers the theory of Copernicus “false and damned and refute him in that most effective way that God will be given to me.” In a confidential meeting held on June 16 by the inquisitors in the presence of the Pope, it was decided to also use torture in order to make Galileo confess; in any case it is decided that his Dialogue will be prohibited. The last interrogation is held on 21 June: Galileo preliminarily declares that he has nothing to say; asked if he supported or had supported the heliocentric doctrine, he replied that “before the determination of the Congregation of the Index and before that precept was made to me [as he now calls the admonition of Bellarmine of February 26, 1616] I was indifferent and had the two opinions, that is, of Ptolemy and Copernicus, for disputable, because either one or the other could be true in nature; but after the aforementioned determination, ensured by the prudence of the superiors, all ambiguity ceased in me, and I held, as I still hold, the opinion of Ptolemy, namely the stability of the Earth and the mobility of the Sun, as very true and unquestionable “.
The next day, in the Chapter Hall of the Dominican convent adjacent to the church of Santa Maria sopra Minerva, the sentence signed by seven inquisitors out of ten is read in Italian to a kneeling Galileo.
I Galileo, son of the q. Vinc.o Galileo di Fiorenza, my age of 70, with institute personally in court, and kneeling before you Emin.mi and Rev.mi Cardinals, throughout the Christian Republic against the heretical pravity general Inquisitors; having before my eyes the sacred Gospels, which I touch with my own hands, I swear that I have always believed, I believe now, and with the help of God I will believe for the future, all that the Sa Cattolica holds, preaches and teaches and Apostolic Church. But why from this S. Off.o, for having me, after having been with a precept from the same juridically intimated that all the time I had to leave the false opinion that the sun is the center of the world and that it does not move and that the earth does not is the center of the world and that it moves, and that I could not keep, defend or teach in any way, either in voice or in writing, the said false doctrine, and after having been notified that said doctrine is contrary to Sacred Scripture, written and given to the press a book in which I deal with the same doctrine already damned and give reasons very effectively in favor of it, without making any solution, I have been judged vehemently suspected of heresy, that is to have held and believed that the sun may it be the center of the world and immovable and that the earth is not center and that it moves; Therefore, if I want to remove from the minds of the Eminences Vere and of every faithful Christian this vehement suspicion, rightly conceived of me, with sincere heart and unfinished faith, I abjure, curse and hate the aforementioned errors and heresies, and generally any and all other error, heresy and sect contrary to the Holy Church; and I swear that for the future I will never say or assert, verbally or in writing, such things for which you may have a similar suspicion of me; but if I know any heretic or who is suspected of heresy, I will denounce him to this Holy Office, or true to the Inquisitor or Ordinary of the place, where I will be.
After reading the sentence Galileo abjured: I also swear and I promise to fulfill and fully observe all the penances that have been or will be imposed on me by this S. Off.o; and contravening any of my promises and oaths, which God forbid, I submit to all the penalties and punishments that are from the sacred canons and other general and particular constitutions against similar criminals imposed and promulgated. So God help me and these holy Gospels of his, which I touch with my hands. I, Galileo Galilei, have abjured, sworn, promised and obligated myself as above; and in faith of the truth, with my own hand I signed the present coupon of my abjuration and recited it word by word, in Rome, in the convent of Minerva, this day June 22, 1633. I, Galileo Galilei, I abjured as above, hand own.