Galileo's Daughter (11 page)

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 for 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 over the ensuing decades by untold numbers of Church officials and other Catholics:

I most firmly accept and embrace the Apostolic and ecclesiastical
traditions and the other observances and constitutions of the
Church. I also accept Sacred Scripture in the sense in which it has
been held, and is held, by Holy Mother Church, to whom it belongs
to judge the true sense and interpretation of the Sacred Scripture,
nor will I accept or interpret it in any way other than in accordance
with the unanimous agreement of the Fathers.

Galileo’s
Letter to Grand Duchess Cristina
indirectly charged his opponents with violating this oath by bending the Bible to their purposes. His opponents, on the other hand, judged Galileo guilty of the same crime. His only hope of winning the argument lay in producing proof positive for the Copernican system. Then, since no truth found in Nature could contradict the truth of Scripture, everyone would realize that the fathers’ judgment about the placement of the heavenly bodies had been hasty, and required reinterpretation in the light of scientific discovery.

December 1615 thus brought Galileo to Rome brandishing new support for Copernicus—derived from observations of the
Earth,
not the heavens. The tidal motions of the great oceans, Galileo believed, bore constant witness that the planet really did spin through space. If the Earth stood still, then what could make its waters rush to and fro, rising and falling at regular intervals along the coasts? This view of the tides as the natural consequence of the turning Earth had originally occurred to him nearly twenty years previously, at Venice, when he boarded the barges that carried drinking water into the city from Lizzafusina. Watching the way the large cargoes of water sloshed in response to any changes in the ships’ speed or direction, he had found a model for the ebb and flow of the Adriatic and the Mediterranean.

Now, lodged at the Tuscan embassy in the Villa Medici, Galileo passed the early part of January 1616 setting down in writing for the first time his theory of the tides. His social life during this labor consisted of meeting with fifteen to twenty men at a time in the homes of various Roman hosts, where he argued Copernicus’s cause in his most compelling style. The nervous Tuscan ambassador, Piero Guicciardini, fairly choked through these evenings, for he dreaded the possible cost of Galileo’s actions.

“He is passionately involved in this fight of his,” Guicciardini complained to the grand duke, “and he does not see or sense what it involves, with the result that he will be tripped up and will get himself into trouble, together with anyone who supports his views. For he is vehement and stubborn and very worked up in this matter and it is impossible, when he is around, to escape from his hands. And this business is not a joke, but may become of great consequence, and the man is here under our protection and responsibility.”

Galileo needed the evidence of the tides to support Copernicus because his astronomical findings to date had failed to prove the Earth’s motion. It was all very well to argue, as Galileo did, that a rotating, revolving Earth made for a more rational universe—that asking the innumerable, enormous stars to fly daily around the Earth at fantastic speeds was like climbing to a cupola to view the countryside and then expecting the
landscape
to revolve around one’s head. Such reasoning, however, said nothing about the way God had actually constructed the firmament.

Even Galileo’s discovery of the phases of Venus, which he had dealt as a death blow to the Ptolemaic system, did not constitute proof of the Copernican. The planetary system of Danish astronomer Tycho Brahe could take Venus by the horns and still enable the Earth to remain immobile. According to the Tychonic order, the five planets orbited the Sun, while the Sun—surrounded by Mercury, Venus, Mars, Jupiter, and Saturn—circled the stationary Earth. Although Tycho had based this theory on decades of careful observations, Galileo dismissed his plan as even sillier than the Ptolemaic. Since he could not prove the Copernican system by telescope alone, however, he turned to the tides to cement the case. He required the seas to rise to the rescue, not merely of Copernicus’s reputation or his own, but to preserve Italy’s future scientific preeminence and—most important—to protect the honor of the Catholic faith. For if the Holy Fathers banned Copernicus, as rumor predicted they might do at any moment, then the Church would endure ridicule when a new generation of telescopes, probably manned by infidels, eventually uncovered the conclusive evidence for the Sun-centered system.

The waters of the world occupy a moving vessel, Galileo wrote in his “Treatise on the Tides.” This vast container of water turns on its axis once every day and travels around the Sun once a year. The combination of the two Copernican motions accounts for all tides. The timing and magnitude of specific tides in different locations, however, depend also on many contingent factors, including the extent of each body of water (this was why ponds and small lakes lacked tides), its depth (and consequently the volume of fluid involved), the way it orients itself on the globe (since an east-west waterway like the Mediterranean experienced more dramatic tides than the nearly north-south Red Sea), and its nearness to other bodies of water (which proximity could cause powerful currents and floods, as at the Straits of Magellan where the Atlantic met the Pacific Ocean). Galileo, who never once left Italy, had gathered reports from far and wide to flesh out his explication.

“To hold fast the basin of the Mediterranean and to make the water contained within it behave as it does surpasses my imagination,” Galileo declared, “and perhaps that of anyone else who enters more than superficially into these reflections.”

But here, again, the fact that Galileo could not account for the tides without moving the Earth did not prove that the Earth moved. What’s more, his theory of the tides, though carefully crafted and eminently reasonable, was wrong. Throughout his life he ignored the true cause of the tides, which rise and fall by the pull of the Moon, because he failed to see how a body so far away could exert so much power. To him, the concept of “lunar influence” smacked of occultism and astrology. Galileo occupied a universe without gravity
*
As for the force that made moons orbit planets and planets orbit the Sun in Galileo’s cosmology, they might as well have been pushed around by angels.

Kepler, Galileo’s German contemporary, made the Moon the centerpiece of his own tidal theory. Kepler’s thinking, however, riddled with mystical allusions to the Moon’s affinity for water, alienated Galileo’s strictly logical mind. (Kepler had even posited intelligent beings on the Moon, as builders of the features observed from Earth.) What’s more, Galileo may have had some trepidation about relying on the testimony of a German Protestant.

Galileo presented his manuscript treatise on the tides to one of the newest cardinals in Rome, twenty-two-year-old Alessandro Orsini, a cousin of Grand Duke Cosimo. Galileo wanted Cardinal Orsini to pass the paper on to the current pope, Paul V, whose endorsement might help settle the issue. The young cardinal dutifully delivered the paper, but the sixty-three-year-old pontiff refused to read it. Instead, His Holiness pushed the moment to its crisis by convening expert consultors to decide once and for all whether the Copernican doctrine could be condemned as heretical.

The pope summoned his theological adviser, Roberto Cardinal Bellarmino, the preeminent Jesuit intellectual who had served as inquisitor in the trial of Giordano Bruno. Cardinal Bellarmino, the “hammer of the heretics,” had once confided to Prince Cesi of the Lyncean Academy that he personally considered the opinion of Copernicus heretical, and the motion of the Earth contrary to the Bible. (This admission prompted Cesi to wonder whether
De revolutionibus
would ever have been published had Copernicus lived after the Council of Trent, instead of before it.)

Bellarmino knew Galileo from meetings at social occasions over a period of some fifteen years, had viewed Jupiter’s moons through his telescope in 1611, and highly respected his achievements, which he could appreciate more than most, having studied astronomy himself at Florence. The only fault Cardinal Bellarmino found with Galileo was the man’s insistence on treating the Copernican model as a real-life scenario instead of a hypothesis. After all, there was no proof. The cardinal further opined that Galileo should stick to astronomy in public and not try to tell anyone how to interpret the Bible.

Roberto Cardinal Bellarmino

The Council of Trent, Cardinal Bellarmino took pains to point out, prohibited the interpretation of Scripture contrary to the common agreement of the Holy Fathers—all of whom, along with many modern commentators, understood the Bible to state clearly that the Sun traveled around the Earth. “The words ‘the Sun also riseth and the Sun goeth down, and hasteth to his place where he arose, etc’ were those of Solomon,” Cardinal Bellarmino wrote,

who not only spoke by divine inspiration but was a man wise above all others and most learned in human sciences and in the knowledge of all created things, and his wisdom was from God. Thus it is not likely that he would affirm something which was contrary to a truth either already demonstrated, or likely to be demonstrated. And if you tell me that Solomon spoke only according to the appearances, and that it seems to us that the Sun goes around when actually it is the Earth which moves, as it seems to one on a ship that the shore moves away from the ship, I shall answer that though it may appear to a voyager as if the shore were receding from the vessel on which he stands rather than the vessel from the shore, yet he knows this to be an illusion and is able to correct it because he sees clearly that it is the ship and not the shore that is in movement. But as to the Sun and the Earth a wise man has no need to correct his judgment, for his experience tells him plainly that the Earth is standing still and that his eyes are not deceived when they report that the Sun, Moon, and stars are in motion.

Galileo was still in Rome in February 1616 when the inevitable happened. At the request of Pope Paul V, who devoted his papacy to promulgating Council of Trent reforms, the cardinals of the Holy Office framed the Copernican argument as two propositions to be voted on by a panel of eleven theologians:

I. The Sun is the center of the world, and consequently is immobile of local motion.

II. The Earth is not the center of the world, nor is it immobile, but it moves as a whole and also with a diurnal motion.

The unanimous verdict of the panel pronounced the first idea not only “formally heretical,” in that it directly contradicted Holy Scripture, but also “foolish and absurd” in philosophy. The theologians found the second concept equally shoddy philosophically, and “erroneous in faith,” meaning that although it did not gainsay the Bible in so many words, it nevertheless undermined a matter of faith.

The consultors cast their ballots on February 23 and reported their conclusions to the Holy Office of the Inquisition the following day. Although no public announcement came out of official chambers, Galileo got a special summons and personal notification of the outcome almost immediately.

On February 26, two officers of the Inquisition came to collect him from the Tuscan embassy. They escorted him to the palace of Lord Cardinal Bellarmino, who personally met him at the door, holding his cap, as was his polite custom, and bade Galileo follow him to his chair. There he told Galileo about the independent panel’s ruling against the Sun’s placement at the center of the universe. Speaking as the pope’s representative, Bellarmino admonished Galileo to abandon defending this opinion as fact. No record survives of Galileo’s spontaneous reaction to this dashing of all his hopeful efforts, but he doubtless bowed to the cardinal’s command.

Several other people showed up unexpectedly at the cardinal’s house to see Galileo, led by Father Michelangelo Seghizzi, the Dominican commissary general of the Holy Office of the Inquisition, who had been one of the eleven voting theologians on the recent panel. He also claimed to speak for the pope, telling Galileo to relinquish the opinion of Copernicus or else the Holy Office would proceed against him. Again Galileo acquiesced.

The following week, on March 5, the Congregation of the Index published a proclamation that expounded the official position on Copernican astronomy—namely, that it was “false and contrary to Holy Scripture.” The decree also named names and called for action. It suspended Copernicus’s book until corrections were made in it, “so that this opinion may not spread any further to the prejudice of Catholic truth.” It also cited another book, by the Carmelite father Paolo Antonio Foscarini, who had enthusiastically supported Copernicus by quoting chapter and verse from both
De revolutionibus
and the Bible, to show how the two texts could be reconciled. Foscarini fared far worse than Copernicus in the decree, because his book was condemned outright—prohibited and destroyed. Nor did the dismal aftermath end there. The printer in Naples who had published Foscarini’s book was arrested soon after the March edict, and Father Foscarini died suddenly in early June, at the age of thirty-six.