Shea and Artigas - Galileo in Rome

by William R. Shea

  The dinner was held in the vineyard of Monsignor Malvasia on the summit of the Janiculum, the highest of the Roman hills. The lodge where it took place was demolished in the nineteenth century and replaced by a small villa whose view is now obstructed by the main building of the American Academy in Rome. In the seventeenth century the view from the vineyard was unimpeded. The Villa Medici could be seen on the Pincio to the left, and straight across the Tiber was the basilica of St. John Lateran, some three miles away. Galileo trained his telescope on the loggia above the side entrance of the church to allow the guests to read for themselves the chiselled inscription that had been placed there by Sixtus V in 1585, the first year of his pontificate: Sixtus/Pontifex Maximus/anno primo. The participants who enjoyed this close-up view were an international group: Johann Faber and Johann Schreck hailed from Germany, Jan Eck from Holland, and Joannes Demisiani from Greece. The Italian contingent consisted of five persons and included Galileo, Cesi, and Giulio Cesare La Galla, a professor of philosophy at the University of Rome.

  Faber was a medical doctor who taught at the University of Rome, and acted as Cesi’s closest collaborator. It was Faber who informed Mark Welser about the banquet and mentioned that they had observed the satellites of Jupiter and read the inscription on the loggia of the basilica. This is confirmed by La Galla, who adds that they were also able to count the windows, even the smallest ones, on the facade of the residence of the duke of Altemps on a hill in the countryside some 25 kilometers away. It was also on this occasion that the new instrument, which Galileo had called in Latin perspicillum (lens) and in Italian occhiale (spyglass), was given the name under which it is now known, telescope, by the Greek scholar Giovanni Demisiani or by Cesi himself.

  A CARDINAL ENQUIRES

  We mentioned that Robert Bellarmine was the most distinguished professor at the Roman College when Galileo visited the prestigious institution in 1587. By 1611 Bellarmine was even more famous. He had been appointed cardinal 13 years earlier and, at 68, he was still an active member of important Roman Congregations, including the Holy Office. He generally kept abreast of scientific developments and after looking through a telescope, he dropped a note on 19 April to his fellow Jesuits at the Roman College to ask their opinion about Galileo’s discoveries. The four professors of mathematics and natural philosophy, Christopher Clavius, Christopher Grienberger, Odo Maelcote and Giovanni Paolo Lembo, replied on 24 April with a cautious but perfectly adequate endorsement of the Sidereus Nuncius. The telescope had certainly shown stars hitherto invisible, but it was doubtful whether the Milky Way was composed entirely of stars. Saturn looked egg shaped and oblong, unlike Jupiter and Mars, but the two starlets to the left and right were not sufficiently detached to affirm that they were really stars. Venus had phases like the Moon. The surface of the Moon seemed uneven, but Clavius thought it more probable that it was really smooth, while the other Jesuits considered it uneven, although they would not say that the matter was beyond doubt. On the crucial question of Jupiter’s satellites, they all agreed that they were real. Was Bellarmine merely indulging his interest as an amateur astronomer or was he wondering whether the discoveries everyone was talking about might raise theological difficulties? It seems reasonable to assume that Bellarmine was glad to have his colleagues confirm the validity of Galileo’s claims, but he must have sensed that they were potentially troublesome for the Aristotelian natural philosophy that was taught in the Jesuit schools. The mountainous and irregular surface of the Moon was at variance with the traditional notion that the heavens were perfect and unchangeable; the four satellites of Jupiter showed that not all heavenly bodies revolved around the Earth; the phases of Venus established that at least one planet went around the Sun; finally, the countless number of stars altered the picture of the universe. All this was not easy to fit into the grooves of traditional natural philosophy, but Bellarmine’s main concern was with the problems posed by the interpretation of Scripture. The Bible speaks of the Sun rising and setting, and, although it might be possible to interpret such passages as ordinary language and not as a statement of scientific fact, it was surely premature to undertake such a delicate task. Bellarmine may also have been reminded of Bruno’s wild speculations about innumerable worlds and the general belief that this subverted the importance of the incarnation of Christ.

  A few days later, on 17 May, Bellarmine attended a meeting of the Inquisition that minuted, “See whether Galileo, professor of philosophy and mathematics is mentioned in the case of Doctor Cesare Cremonini.” Cremonini had been Galileo’s colleague and friend in Padua, and as early as 1604 both had been denounced to the local Inquisition: Cremonini for dubious orthodoxy in the way he interpreted the immortality of the soul according to Aristotle, and Galileo for believing that the stars determine human behavior. The charges had been quietly dropped, and we can only guess why someone at the Holy Office now wanted to check whether Galileo’s name was associated with that of Cremonini, who continued to be denounced for his views on the immortality of the soul. Galileo’s large circle of acquaintances included several priests but also some notorious bon vivants and controversial figures like Cremonini. Such relationships might have seemed suspect to Bellarmine, but he was a conscientious person and anxious to be fair. A check on anyone spreading novel ideas was in any case a routine matter in Rome during the Counter Reformation, and Galileo probably never heard that his name had cropped up at a meeting of the cardinal inquisitors.

  We must also bear in mind that the pattern of studies for all Jesuit colleges had been laid down in the Ratio Studiorum, a collection of guidelines in which teachers were enjoined to follow St. Thomas Aquinas in theology and Aristotle in philosophy. The prime concern of the Jesuit authorities was orthodoxy and the promotion of a reasonable amount of uniformity in their educational institutions. Lecturers were not to introduce new opinions without consulting their superiors, and those who were prone to novelties or of too free a mind were to be assigned other tasks and removed from teaching. These stringent provisions were confirmed while Galileo was in Rome. On 24 May 1611, the Jesuit general, Claudio Aquaviva, addressed a letter to the society in which he insisted on the implementation of the Ratio. The caution that the Jesuits displayed in accepting Galileo’s discoveries was just what might be expected, but once they were convinced he was right they showed their appreciation handsomely, as we shall soon see.

  PAPAL SALUTE

  While the professors of the Roman College were preparing their report for Cardinal Bellarmine, the Tuscan ambassador had requested an audience with the pope, Paul V, the name Cardinal Camillo Borghese had chosen when elected in 1605. He was the scion of a wealthy and powerful family. Their former seat, the Villa Borghese, is still one of the most admired and frequently visited of the great Roman houses. The famous art collection that it now stores is an extension of the splendid works of art that the Borghese had acquired from the fifteenth century onward. Not unlike Sixtus V, Paul V was a man of considerable energy and determination. He enforced the decrees of the Council of Trent that called for bishops to reside in their own dioceses simply by expelling from Rome those who were there without urgent business. He was not particularly gifted in diplomacy and easily took, and provoked, umbrage. His pontificate was marked by a bitter jurisdictional quarrel with Venice in which Cardinals Baronio and Bellarmine acted for the Holy See while Paolo Sarpi, a friend of Galileo, defended the interests of the maritime republic. The pope, who was a canon lawyer by training, could not brook any behavior that seemed to challenge the legal power of the Church, and he excommunicated the Doge, the Senate, and the whole government of Venice. When this did not produce results, Paul V placed the Republic under interdict; in other words, he forbade priests to administer sacraments. Most of the clergy in Venice, both regular and secular, sided with the Venetian authorities, but the Jesuits and two other religious congregations obeyed the pope and were promptly expelled from the territory of Venice. In 1607, after one year of wrangling, an agreement was
worked out and the pope withdrew his interdict and lifted the excommunication. But no sooner was peace restored in Italy than another conflict arose with England, where James I imposed in 1605 an Oath of Allegiance that ordered his subjects to rejects as “impious and heretical” any papal interference with religious or political affairs in the United Kingdom. Bellarmine was entrusted with making the case for Rome, and this is how he became something of a bogeyman in England and was often portrayed as the archetype of Jesuit cunning.

  At home, Paul V embarked on the immense task of completing St. Peter’s. The plans that Bramante had drawn in 1506 and those that Michelangelo made some 40 years later were never given the green light. The magnificent church that we admire today is the result of a lengthy and often messy story of architectural changes, and it might not have been finished without Paul V, who, in 1607, made the difficult decision to tear down the old ruinous Constantine basilica and extend the new church by a vast nave with an imposing facade by Carlo Maderna. This was nearing completion when Galileo arrived in Rome, but the huge inscription that runs across the facade, PAULUS V BORGHESIUS ROMANUS, was something he was only to see on his next trip in 1615.

  In the summer the pope resided on the Quirinal, but in April, when Galileo and the ambassador paid their courtesy visit, he was still at the Vatican. The Avvisi, which we have mentioned earlier, allows us to follow the pope as he went about Rome in a litter, on horseback, and on foot to inspect public works, preside at religious ceremonies, and promote artistic and cultural activities. This is how we know that the pope had visited the vineyard of Monsignor Malvasia a week before Federico Cesi gave a banquet there in honor of Galileo. To be received by the pope was quite an honor for Galileo, and after the audience he immediately wrote to his friend, Filippo Salviati, knowing full well that Salviati would not only talk about his friend’s Roman success but would pass the letter around:

  I do not have time to write personal letters to all my friends and patrons, and in writing to you I shall imagine that I am writing to all. I have been received and fêted by many illustrious cardinals, prelates and princes who wanted to see the things I have observed and were much pleased, as I was too, on my part, in viewing the marvels of their statuary, paintings, frescoed rooms, palaces, gardens, and so on.

  This morning I went to pay my respects to his Holiness, and I was introduced by His Excellency our illustrious Ambassador, who told me that I had been treated with exceptional favor because his Holiness would not let me say a word kneeling but immediately commanded me to stand up.

  Galileo went on to mention that the Jesuits were all on his side but that not everyone understood what he was about, and he regretted that some (unspecified) people should have written from Florence that the grand duke was ill pleased when he left for Rome. The friendly way with which the pope had received him and the approval of the Jesuits enabled Galileo to dismiss his critics as laughable, but events would show that they were not entirely a joking matter.

  THE NEW LYNCEAN

  Three days after the papal audience, Galileo was solemnly received by Federico Cesi in his palace, which can be admired to this day in the Via della Maschera d’Oro in the heart of Rome. The purpose of the visit was to make Galileo a member of the Lyncean Academy, a privilege that had only been conferred on four persons since 1603. Galileo’s formal acceptance, in Latin, can still be read in the membership book: “I, Galileo Galilei Lyncean, son of Vincenzio, Florentine, age forty-eight years, in Rome. Written in my own hand on 25 April of the year of grace 1611.” In the same year four other members were added, including two who had attended the banquet on the Janiculum, the Roman hill next to the Vatican: Johann Schreck (alias Terentius), who was 35, and Johann Faber, who was 37. All in all, 32 scholars and scientists were admitted before Cesi’s death in 1630, when the activities of the academy ceased.

  The Lyncean Academy was a loose association based on personal ties with Cesi (Prince Cesi after 1613, when this title was conferred on him by the pope), who concentrated all power and control in his own, admittedly generous, hands. He was a patron rather than a scientist, but he had the good sense to recognize Galileo’s greatness and to publish at his own expense Galileo’s Letters on the Sunspots in 1613 and his Assayer in 1623. He fully intended to publish Galileo’s masterpiece, the Dialogue on the Two Chief World Systems, but he died before the work had run the gauntlet of censorship and was licensed for print. Had Cesi been alive in 1632 when the book finally appeared it might have sailed past the shoals of the Inquisition.

  Galileo was always proud to be a member of the Lyncean Academy, and he prominently displayed this title on the cover of his books. But in Rome in 1611 he knew that he had to be active on more than one front, and he did not neglect astronomical observation. Kepler had thought that it would be impossible to determine the periods of Jupiter’s satellites, but Galileo was able to work them out to a very good approximation while in Rome. He also trained his telescope on the Sun, and, by April, he was showing notable people a most unexpected spectacle: The Sun was covered with spots. It was natural for Galileo and for others to wish to examine the Sun as well as the planets, but no one could look at the flaming ball for more than a fleeting instant without being blinded. The solution initially was to place a neutral blue or green lens over the objective of the telescope, or to cover the lens with soot. However, a better method was found by Galileo’s former student, Benedetto Castelli, who let the image of the Sun fall on a screen placed behind the telescope. Galileo was therefore able to see clearly that the surface of the Sun was covered with spots. This was a momentous discovery, since the Aristotelians maintained that nothing changed in the heavens, and the spots were a clear indication that the Sun itself was not made of an imperishable and incorruptible substance.

  A Jesuit professor in Germany, Christopher Scheiner, also saw the sunspots, but he conjectured that they were small satellites like those that Galileo had seen around Jupiter. If they were some kind of clouds, this would indicate that the Sun is not perfect and immutable. In order to avoid this, Scheiner conjectured that they were real bodies orbiting at some distance from the Sun. Galileo rejected this hypothesis and took great care to show that they were on or very close to the surface and that their motion indicated that the Sun rotates on its axis.

  Among Galileo’s Florentine friends in Rome was Monsignor Piero Dini, a nephew of Cardinal Bandini who held high office at the Vatican. Dini was a skillful diplomat, and the advice that he would later give Galileo was among the best he ever received. He was a shrewd observer of the Roman scene, and his letters to friends are a useful source of information. On 7 May 1611 he reported to Cosimo Sassetti in Perugia: “every day Galileo converts some of the heretics who did not believe him, although there are still a few who, in order to escape knowing the truth about the stars around Jupiter, do not even want to look at them.” The reluctance to look through the telescope on the part of people who had made the attempt and seen little or nothing is understandable. The telescope was not only difficult to focus, but the field of vision was extremely small an d, unless it was held very firmly, it was no easy matter to point it at an object as large as the Moon, let alone the small satellites of Jupiter. The answer was to mount the telescope on a stand, but even then impatient or short-sighted philosophers often saw a blurred image that confirmed their prejudices. On 14 May Sassetti replied to Dini, who passed the letter on to Galileo, as we know from a copy that Galileo made himself and is still extant. It embodied the qualms of some professors of the University of Perugia. Since Galileo went to the trouble of copying this letter and then replying to it, the reader will want to see it for himself:

  Loud voices are raised against Galileo. I spoke to two of the main protesters, who would not be converted by Ptolemy himself were he converted! I should be grateful for an answer to an objection that I heard and that seems very reasonable: the spyglass makes us see things that are not really there, or if they exist then they are so small that they exert no influence. It
seems to me that they are saying that there is no shortage of such small objects in the heavens. This objection is buttressed by a large number of arguments and proofs, starting with the creation of Adam, etc, as your Reverence knows better than I do.

  GALILEO FACES OBJECTIONS

  Dini suggested to Galileo that it would be politic to reply to the objections raised by professors of the University of Perugia, and in spite of his hectic activities Galileo took the time to pen a lengthy reply, which he addressed to Dini. The people in Perugia, who could not catch sight of the Jovian satellites and therefore questioned their very existence, just had inferior instruments. Better lenses would show them that these satellites were not optical illusions! Indeed they had been observed all over Europe, and Galileo declared himself ready to pay 10,000 scudi (ten times his annual salary) to anyone who could construct an optical instrument that would place fictitious satellites around one planet but not around all the others. Galileo then discussed at some length the objection that the celestial bodies disclosed by the telescope were so small that they could not exert any influence on earth. This difficulty was raised by those who cast horoscopes, a task that astronomers then considered part of their job. Galileo made it clear that he never intended to affirm or to deny that the newly discovered stars exert some influence, but that “if he had to say something, he would, speaking personally, be very cautious in pronouncing that the Medicean stars lack influence when other stars do. It would seem bold, not to say reckless, to want to limit the knowledge and the working of nature to what I can understand of it.” As we can see, the question had a philosophical edge. It also had a political one: The satellites that bore the name of the Medici had become a matter of state, and Galileo could hardly allow them to be dismissed as lacking influence.