Through the spring and summer of 1615, Galileo sustained yet another long bout of incapacitating illness – aggravated, perhaps, by his recognition of the forces arrayed against him. Indeed he saw himself the focus of a conspiracy. While bedridden, he recast his informal letter to Castelli into a much longer, more referenced treatise addressed to Madama Cristina herself. (Though no printer dared publish the Letter to the Grand Duchess Cristina until 1636, in Strasbourg, manuscript copies enjoyed a wide Italian readership.)
‘Some years ago,’ he began,
as Your Serene Highness well knows, I discovered in the heavens many things that had not been seen before our own age. The novelty of these things, as well as some consequences which followed from them in contradiction to the physical notions commonly held among academic philosophers, stirred up against me no small number of professors – as if I had placed these things in the sky with my own hands in order to upset Nature and overturn the sciences. They seemed to forget that the increase of known truths stimulates the investigation, establishment and growth of the arts; not their diminution or destruction.
Showing a greater fondness for their own opinions than for truth, they…hurled various charges and published numerous writings filled with vain arguments, and they made the grave mistake of sprinkling these with passages taken from places in the Bible which they had failed to understand properly, and which were ill suited to their purposes.
Even though Galileo directed these comments to Madama Cristina, he refrained from accusing her of the same injustices, which she had committed without malice. He reserved his venom for those others who used biblical passages they could not comprehend to condemn the worthy theory of Copernicus, which they had not read. He backed his position by quoting Saint Augustine, who advised moderation in piety and caution in judgment on complex issues, so as to avoid condemning hypotheses ‘that truth hereafter may reveal to be not contrary in any way to the sacred books of either the Old or the New Testament’. In the margins of his fifty-page letter, Galileo footnoted all the theological works he had consulted to construct his thesis concerning the use of biblical quotations in matters of science – allowing the likes of Saint Augustine, Tertullian, Saint Jerome, Saint Thomas Aquinas, Dionysius the Areopagite and Saint Ambrose to defend him against enemies who sought ‘to destroy me and everything mine by any means they can think of’.
Galileo felt he understood the motivation of his detractors: ‘Possibly because they are disturbed by the known truth of other propositions of mine which differ from those commonly held, and therefore mistrusting their defence so long as they confine themselves to the field of philosophy, these men have resolved to fabricate a shield for their fallacies out of the mantle of pretended religion and the authority of the Bible.’
The Holy Fathers of the Church of course occupied a separate category. Yet several of these, Galileo complained, usurped scriptural authority to pronounce judgments in physical disputes, while ignoring any evidence of science to the contrary:
Let us grant then that theology is conversant with the loftiest divine contemplation, and occupies the regal throne among sciences by dignity. But acquiring the highest authority in this way, if she does not descend to the lower and humbler speculations of the subordinate sciences and has no regard for them because they are not concerned with blessedness, then her professors should not arrogate to themselves the authority to decide on controversies in professions which they have neither studied nor practised. Why, this would be as if an absolute despot, being neither a physician nor an architect but knowing himself free to command, should undertake to administer medicines and erect buildings according to his whim – at grave peril of his poor patients’ lives, and the speedy collapse of his edifices.
Galileo took pains to establish the antiquity of the Sun-centred universe, which dated all the way back to Pythagoras in the sixth century BC, was later upheld by Plato in his old age, and also adopted by Aristarchus of Samos, as reported by Archimedes in the Sand-reckoner, before being codified by the Catholic canon Copernicus in 1543. Galileo had good reason to suspect that this theory stood on the verge of suppression, and his Letter to the Grand Duchess Cristina argued passionately against such action:
To ban Copernicus now that his doctrine is daily reinforced by many new observations and by the learned applying themselves to the reading of his book, after this opinion has been allowed and tolerated for those many years during which it was less followed and less confirmed, would seem in my judgment to be a contravention of truth, and an attempt to hide and suppress her the more as she revealed herself the more clearly and plainly. Not to abolish and censure his whole book, but only to condemn as erroneous this particular proposition, would (if I am not mistaken) be a still greater detriment to the minds of men, since it would afford them occasion to see a proposition proved that it was heresy to believe. And to prohibit the whole science would be but to censure a hundred passages of Holy Scripture which teach us that the glory and greatness of Almighty God are marvellously discerned in all His works and divinely read in the open book of Heaven. For let no one believe that reading the lofty concepts written in that book leads to nothing further than the mere seeing of the splendour of the Sun and the stars and their rising and setting, which is as far as the eyes of brutes and of the vulgar can penetrate. Within its pages are couched mysteries so profound and concepts so sublime that the vigils, labours and studies of hundreds upon hundreds of the most acute minds have still not pierced them, even after continual investigations for thousands of years.
Having hereby framed his thoughts on paper, Galileo felt the gravity of the situation propelling him to Rome, where he intended to free his reputation of any whisper of heresy, and also to defend the burgeoning study of astronomy with new weapons of his own devising.
Grand Duke Cosimo gave Galileo permission to make the journey – over the objections of his Tuscan ambassador there, who judged Rome a dangerous place for the court philosopher ‘to argue about the Moon’. Corridors leading to the Vatican and the Holy Office of the Inquisition already hummed with the controversy of his doctrines.
[VII] The malice of my persecutors
GALILEO ISSUED HIS CALL for a distinction between questions of science and articles of faith at an anxious moment in Church history.
Stunned by the Protestant Reformation fomented in Germany around 1517, the Roman Church struck a defensive posture throughout the sixteenth and seventeenth centuries called the Counter-Reformation. The Church hoped quickly to close the rift that had split Protestantism from Catholicism by convening an ecumenical council, but intrigues and obstacles of all sorts – including disputes over where to stage the event – postponed the meeting for many years, while the rift continued to widen. Finally Pope Paul III (the same pontiff honoured in the dedication of Copernicus’s book) convened bishops, cardinals and leaders of religious orders at Trent, where Italy bordered the Holy Roman Empire of the German nation. On and off over a period of eighteen years, from 1545 to 1563, the Council of Trent debated and voted and ultimately drafted a series of decrees.* These dictated how the clergy were to be educated, for example, and who was empowered to interpret Holy Scripture. Rejecting Martin Luther’s insistence on the right to a personal reading of the Bible, the council declared in 1546 that ‘no one, relying on his own judgment and distorting the Sacred Scriptures according to his own conceptions, shall dare to interpret them’.
After the council finally concluded the twenty-five sessions of its long-drawn-out deliberations, its decrees became Church doctrine through a series of papal bulls (so named after the bulla, or round lead seal, affixed to pronouncements from the pope himself). In 1564, the year Galileo was born, certain important points from the debates were formulated into a profession of faith, worded by the Council of Trent and solemnly sworn