A defensive strategy based on clandestine pamphlets and covert negotiations by mediators proving insufficient, Galileo decided in late 1615 to travel to Rome again to justify his position. But for him, this meant having the truth of his theories accepted, and Rome certainly did not offer a suitable climate for this, despite the apparent openings of a few years before. In Rome the atmosphere was more and more oppressive, increasingly barred to free discussion and impermeable to all innovation, a climate described by Tommaso Campanella, who knew it intimately, as 'horrendous', filled with 'ignorance and fear', a time of black mourning clothes, 'dark, nocturnal, hostile, infernal, treacherous', suggesting unnatural death. And such a climate had been the experience of many in previous years.

 

Concerned and distraught, the Tuscan ambassador to Rome, Piero Guicciardini, sent dispatches to Florence to inform the Court of how Galileo 'fiercely defended his opinions', how he was subject to 'extreme passion and showed little discipline and prudence in controlling it', and how that 'sky of Rome' was 'very dangerous' for him. Guicciardini warned that Rome was not a 'place in which to come and dispute about the Moon', and he was right.

 

On March 1, 1616 in an apparently private session held at Bellarmine's home, the Congregation of the Index gave its verdict. A prohibition was placed on the Lettera sopra l' oppinione de' pittagorici e del Copernico [Letter concerning the Opinion of the Pythagoreans and Copernicus] by the Calabrian Carmelite, Paolo Antonio Foscarini, guilty of having attempted conciliation by finding analogies between Copernicus' theories and many passages in Holy Scripture. Suspension until corrected, 'donec corrigantur', was imposed on the De revolutionibu s by Copernicus and the Commentarii in Job by Diego de Zuņiga, a Spanish theologian who had given a verse in the Book of Job a pro-Copernican interpretation. Although a previous opinion issued by the Inquisition's theological consultants pressed for a sentence of formal heresy, the decree declared the heliocentric theory to be false but not heretical, and Galileo himself was not even mentioned. He received only a verbal caution from Cardinal Bellarmine, which he was obliged to accept. The lightness of the sentence was owing, it seems, to the intervention of the Cardinals Bonifacio Caetani and Maffeo Barberini (the future Pope Urban VIII), who were opposed to labelling as heretical the mobility of the Earth. A further factor was presumably Pope Paul V's debt to the Grand Duke of Tuscany, Cosimo II de' Medici, who had actively supported his election to the papacy, and who would have been indirectly damaged by the infliction of a severe sentence on his Chief Mathematician.

 

Galileo, at first optimistic, interpreted the verdict of the Congregation of the Index as aimed only at those who had seen analogies between Copernican thought and Holy Scripture. 'From the work of Copernicus himself,' he wrote in relief to Curzio Picchena, Secretary of State of the Grand Duchy of Tuscany, 'they will eliminate ten verses of the dedicatory preface to Paul III, in which he hints that he does not consider his doctrine opposed to Scripture.' But his optimism was soon to fade. When Galileo requested Cardinal Bellarmine to deny the false rumours circulated by his detractors that he had been forced to make a humiliating abjuration in Rome, the Cardinal's declaration was conclusive: no abjuration had been demanded of Galileo, nor had 'healthy penitence' been inflicted on him; but 'the doctrine attributed to Copernicus that the Earth moves around the Sun and the Sun stands at the centre of the world without moving from east to west', was 'contrary to Holy Scripture and in no case could be defended or held.' In the Letter to Christine of Lorraine, Galileo had feared the possibility that 'this particular proposition' of the De revolutionibus might be 'condemned as erroneous', on the grounds that this would be 'of greater detriment to the minds of men' than if the whole book were prohibited, because it would mean that 'a proposition had been proved that it was a sin to believe.'

In spite of this, Galileo asked for and was granted permission to stay longer in Rome. His fighting spirit or, in the words of the increasingly agitated Guicciardini, his 'confirmed habit of taming the friars' led him, although at risk of falling 'into the deepest abyss', not only to defend the independence of scientific research but also to claim justice, rightly convinced of being the victim of those 'monkish persecutions' from which Picchena had tried to protect him. He wrote:

 

to hope for the longed-for peace would, moreover, be entirely vain, both because envy is immortal, and because my enemies have found a way to torment me with impunity, by disguising themselves with si mulated religion to make me appear devoid of true religion.

 

This reveals a bitterness equal to that experienced a few weeks earlier at a meeting with his main accuser, Tommaso Caccini, who had expressed scorn for his 'simulated repentance' and had accused him of having 'a mind filled not only with great ignorance but with poison, and devoid of charity.'

 

All told, Galileo returned to Florence defeated, and was compelled from then to fight secret battles with the blunted weapon of a mutilated Copernicanism, in an Italy where no one - as Sarpi lamented - could live safely without a mask to protect him. Such a device masked not only men, but also books, persistently corrected, to disguise with convenient hypotheses all the proven scientific truths that could cast any doubt on the credibility of Scripture.