The Theory of Heliocentrism

By mid-1632, the swirling chaos of the Thirty Years War had reached all the way to the western edge of the European continent, drawing in Spain and France. As it expanded in scope, the war had less and less to do with earnest questions of religion and more and more to do with realpolitik — with questions of territory and economics and temporal influence. Catholic Spain and the Holy Roman Empire were not the allies but the enemies of Catholic France, which made common cause against them with Protestant Sweden and Denmark.

It was, whatever else it may have been, a sign of the slow-rolling secularization of Europe. Once upon a time, popes had been able to raise grand armies of their own, and in some cases even lead them into glorious battle. Those days were gone now. The so-called “Papal States” of Italy, the ones under the direct control of the pope, had a military of their own, but not one large enough to be a factor much beyond their borders. Otherwise, the Holy Father had only moral authority to bring to bear beyond his home peninsula. When Catholics fought with and killed other Catholics, as was now happening, the Catholic Church became more a reflection of the chaos than a solution to it. Factionalism ruled the day as the people inside the Church picked sides — often the sides that seemed most likely to be of service to their worldly ambitions.

Pope Urban VIII had long been wary of the Holy Roman Empire to his north, remembering how an imperial army had marched down the Italian Peninsula and sacked its namesake city in 1527. He was therefore inclined to cast his lot with France and, tacitly at least, with Protestant Scandinavia, as a bulwark against any repeat of that humiliation. Others leaned the opposite way.

Among those others was the Medici family of Florence, who had for decades been the heated rivals of Urban’s own Barberini clan. The conflict was personal: it was actually in Florence that the Barberinis had first risen to prominence during the last century, only to be effectively driven out of that city by the Medicis, who brooked no rival to their supremacy in Tuscany. The Barberins had decamped to Rome and prospered there, culminating in the elevation of Urban to the papacy. Yet the old antagonism abode. Naturally, if the Barberinis supported France, the Medicis would have to be on the side of the Spanish and Germans. The same was true of the many-tendriled Borgia clan, who had traditionally been no friends of the Medicis themselves, but who were prepared to join an alliance of convenience with them if it might bring the upstart Barberinis down a peg or two. The Medicis and Borgias openly hectored Urban over his vanity and corruption and his tacit support for the Scandinavian Protestants who had rejected his God-given authority; cardinals from the opposing factions sometimes came to blows. Seeing real or imagined enemies and conspiracies everywhere, Urban adopted a bunker mentality, seldom appearing in public unless he was ringed in by his loyal Swiss Guard, refusing to eat a bite of food before his taster had digested his fill of it and been carefully inspected for signs of poisoning.

It was into this tense, backbiting atmosphere that Galileo’s book was dumped in the summer of 1632. Its reception in Rome would have as much to do with the fact that it arrived from Florence, having issued from the pen of a favored servant of the Medicis, as it did with anything contained between its covers.

The series of events that would go down in history as “The Galileo Affair” began when Pope Urban complained about the book to Niccolò Riccardi, his chief censor, the man currently in charge of the Index of Forbidden Books. The pope’s displeasure placed Riccardi in an embarrassing position; he had, after all, personally approved the publication of the Dialogue Concerning the Two Chief World Systems, as long as it included a preface in which Galileo denied that he wished to prove heliocentrism to be a physical truth, notwithstanding that the rest of the book set out quite single-mindedly to do exactly that. Now Riccardi could only engage in damage control. He sent a hasty note to the office of the Inquisition in Florence, writing that “Galileo’s book has arrived, and there are many things that are not acceptable and the authorities want to see revised. The Sovereign Pontiff has ordered — but only mention my name — that the book is to be withheld. See that the order is obeyed.”

A postscript to the note acts as a telling testament to the climate of suspicion in which the pope was living. At the bottom of the book’s title page was an icon showing three dolphins intertwined with one another, underneath the Latin phrase Grandior ut proles, which translates to “I have grown as my family.” Pope Urban suspected that the dolphins were a satirical stand-in for the brother and nephews whom he had promoted to the rank of cardinal, the one while he was still a teenager, even as the Latin phrase referred to his corruption in many other aspects of his station. It was a leap even by the convoluted standards of seventeenth-century symbolic iconography, but one that Urban hadn’t hesitated to make. (A sign of a guilty conscience?) “Let me know as soon as possible whether the device with the three fish is the printer’s or Galileo’s,” wrote Riccardi to the Florentine Inquisition at the pope’s behest.

Riccardi was soon able to report that the icon was entirely innocent, being merely the standard logo of the printer Giovan Battista Landini, as seen on all of the books that came out of his shop. But when it came to the Florentine Inquisition’s primary task of preventing the distribution of the Dialogue, the damage was largely already done. Hundreds of copies had already been sent the length and breadth of Italy and even beyond.

For his part, Niccolò Riccardi wasn’t thrilled to be acting as Urban’s agent in this matter. He had no beef of his own with Galileo, and by all indications saw little point in launching a crusade against him in the name of geocentrism, a view of the cosmos that was swiftly becoming untenable for anyone who knew anything about astronomy. It seemed to him the wrong battle for the Church to pick at this juncture, and he persistently tried to minimize the fallout. He suggested that Galileo’s book should be treated much as Copernicus’s had been, that it should merely undergo some judicious editing in the form of crossed-out sentences rather than being banned indiscriminately. “Comfort the author and tell him to keep his spirits up,” he went so far as to write to the Florentine Inquisition.

But even as the man who ought to have been his chief antagonist was oddly sympathetic to him, Galileo had no shortage of genuine enemies in Rome, many of them the same figures he had intellectually lacerated with such joyous abandon in the drawing rooms of the city’s elites during earlier years. He had frequently behaved arrogantly toward the Jesuit order, the one priestly order in Rome who might be most reasonably expected to come to his defense. As a result, they sat on their hands as the crisis enveloped him. Even Riccardi was only prepared to go so far in trying to mitigate Pope Urban’s wrath.

On September 4, 1632, fed up with his censor’s endless temporizing, Urban called him on the carpet at his palace. Also present at this meeting was Francesco Niccolini, the Florentine ambassador to Rome. He and Riccardi were informed that the pope intended to create a special commission “to study every detail” of Galileo’s book, “word by word, because this is the most perverse thing that one can have to deal with.” Niccolini wrote back to Florence after the meeting that “when his Holiness gets something in his head, that is the end of the matter, especially if someone tries to resist, oppose, or defy him. Then he takes a hard line and shows no consideration whatsoever.”

Urban’s commission quickly found a record of the pledge that Galileo had made in 1616 not to continue to advocate for heliocentrism, a pledge of which Riccardi had been completely unaware when he had approved the publication of the Dialogue. “This is enough to ruin him,” he lamented now. On September 25, it was decided that Galileo must be brought to Rome and placed on trial for heresy.

What followed was not an immediate arrest, but rather a delicate dance of negotiation that involved not only the Inquisition and Galileo himself but the governments of Rome and Florence. Galileo, who still seemed to be treating the whole episode as more of an annoyance than a deadly threat, pleaded that his health was so poor that he was unlikely to survive the trip to Rome, especially given that the plague was showing signs of flaring up once again. He pulled out all the stops in this campaign, going so far as to add a couple of years to his already advanced age of 68 and enlist a team of respected doctors to declare that he was suffering from a dizzying variety of ailments, from chronic stomach pain to melancholia of the spirit. Meanwhile Ferdinando II de’ Medici, Grand Duke of Tuscany, was conducting a parallel negotiation with Rome, in which he sought to ensure that Galileo would at the very least not be thrown into a dungeon like any other common prisoner if he did have to show up there.

And that he would; Galileo could delay the proceedings, but he couldn’t weasel out of them. Having exhausted the last of his stratagems, he finally came to Rome, for the sixth and final time in his life, on February 13, 1633. On the bright side, Ferdinando had been able to get the pope and his Inquisition to agree to let Galileo stay at the Florentine embassy in Rome while he awaited trial.

After all of the effort to bring him to the city, said trial was weirdly long in coming, almost as if Urban was deliberately leaving the defendant to stew in his own juices for a while. Ambassador Niccolini felt for his charge, so much so that he arranged a meeting with Urban in March to try to either move events forward or, even better, convince the pope that he had made his point and could let the old man go free. But Urban was implacable. The Inquisition could not be hurried; this case must be allowed to run its full, exemplary course for the good of all the faithful. “There is an argument,” he said, “that no one has ever been able to answer, namely that God, who is omnipotent, can do anything. And if he is omnipotent, who can bind him?” Niccolini must have wondered whether the pope was really thinking of God or of himself when he made this non sequitur of an argument, which didn’t have much of anything to do with whether God, in his infinite unboundedness, had made the Earth move around the Sun or vice versa.

At last, a date for the trial’s beginning was set: April 12, 1633. Galileo would be taken into custody by the Inquisition on this day, but he would not be placed in a prison cell; instead he would be kept under house arrest in a spartan but warm and dry apartment. Ambassador Niccolini gave him some advice about the life-or-death court proceeding that awaited him.

I begged him, in the interest of a quick resolution, to agree to what they want him to believe about the Earth’s motion. He was extremely distressed by this, and since [then] I see him so depressed that I fear greatly for his life. I will try to obtain permission for him to keep a servant and to have other conveniences. We all want to cheer him up, and we seek the assistance of friends and those who play a role in these deliberations, because he really deserves to be helped. Everyone in the embassy is extremely fond of him and feels the greatest sorrow.

When the morning of the trial came, no one knew how Galileo planned to answer the charges against him. He had retreated into himself, keeping no one’s counsel but his own. His friends would have been appalled if they had known the mocking and defiant posture he had decided to adopt, in a misreading of his situation that might very well prove fatal.

That said, the scene that ensued on April 12 was not so dramatic as Galileo’s posterity would be tempted to envision it. The location was a small, anonymous-looking bureaucratic meeting room. The pope was not present; nor were any spectators. Nominally at least, Galileo’s fate rested in the hands of just one man, a Commissioner Vincenzo Maculano, who filled the roles of judge and jury from his seat next to that of the prosecutor, Carlo Sinceri. Other than these two, there were only a few clerks and scribes present to record what transpired. The Inquisitors spoke to Galileo in Latin, the language of the Church, but Galileo made his replies in ordinary Italian. It was a subtle act of rebellion to serve as an appetizer; Galileo would become less subtle as the morning wore on.

After working through some preliminary findings of fact — “Did you yourself write this book that the court has in evidence?”, etc. — the prosecutor turned to the injunction which Galileo had been given by Cardinal Bellarmine seventeen years earlier. Galileo insisted that the official summary he was shown — which stated that he had agreed “to relinquish altogether the opinion that the Sun is the center of the universe and at rest and that the Earth moves; nor henceforth to hold, teach, or defend it in any way, verbally or in writing” — didn’t jibe with his own memory of the meeting. He believed he had agreed only not to insist upon heliocentrism as a physical truth, as opposed to a merely instrumental one. And the last-minute preface he had added to his Dialogue satisfied that requirement, he said.

It was at this point that the hearing took a turn for the bizarre, when Galileo abruptly changed tack and stated that he had actually written his latest book in order to refute heliocentrism. In it, he said, “I proved the contrary of the Copernican opinion, and showed how weak and inconclusive the arguments of Copernicus were.” It became clear now that he was treating his day in court as just another of the intellectual jousts with which he had delighted so many drawing-room audiences over his life, baiting and toying with his own judge and prosecutor, subjecting them to the same condescending mockery which he had rained down on Simplicio in his book. It was a brutal miscalculation on his part. Maculano and Sinceri may not have been astronomers, but they weren’t simpletons either. That Galileo was spinning these patently untrue yarns under oath left him open to all kinds of retribution, something he should have been more than smart enough to understand. When it became clear that he was undermining his own cause with his mockery, a disgusted Commissioner Maculano dismissed him from his court.

Galileo was saved from the worst potential consequences of his arrogance and bad judgment by luck. For the fact was that Vincenzo Maculano, much like Niccolò Riccardi, had little passion for this fight. Quite possibly more than half suspecting himself that heliocentrism was the physical truth of the heavens, he had no particular desire to make a martyr for that truth out of Galileo Galilei, no desire to burn a frail old man alive for the crime of writing a book of natural philosophy. Rather than calling for a torturer or pronouncing Galileo fit only for execution then and there, he spent the fortnight after the defendant had mocked him in court trying to negotiate a settlement that would be acceptable to all parties, one that wouldn’t require Galileo to share the fate of Giordano Bruno. He finally secured an agreement from Pope Urban’s camp: if Galileo would explicitly recant his heliocentrism and apologize for breaking his prior pledge to Cardinal Bellarmine, he could be allowed to live out the rest of his days under house arrest rather than face execution or imprisonment in a dungeon.

By the usual standards of the Inquisition, it was a generous offer. Now Maculano just had to sell it to Galileo. He was fortunate in this; when Maculano came to him on April 28, he found Galileo to have undergone a transformation from an acerbic mocker into a receptive, humble suppliant. It seemed that Galileo’s friends had managed to impress the gravity of his situation upon him at long last, and that he had realized that he did not wish to martyr himself on the cross of heliocentrism any more than Maculano wanted to place him in that position. “I made him see that he was wrong and had gone too far,” Maculano reported to his scribes after their meeting. “As if relieved to realize his error, [Galileo] said he was ready to make a judicial confession.”

Maculano wrote to Cardinal Barberini, the pope’s brother, in a more formal register, stating that “I hope that his Holiness and your Eminence will be pleased that the case can now be settled without further difficulty. The Tribunal will retain its reputation and be able to deal leniently with the accused, who, whatever the outcome, will recognize the favor that has been done to him.”

Just two days after Maculano had spoken with Galileo privately, the astronomer came to him publicly in his courtroom for the second time. His tone at this hearing was the polar opposite of the last one — submissive instead of arrogant, sober instead of mocking. Speaking Latin now, he held to the fiction that he had written the Dialogue to disprove rather than prove heliocentrism, for to do otherwise would make it impossible for Maculano to avoid punishing him for lying under oath in God’s own court of justice. Yet that fiction had now become a polite instead of a satirical one. Doing his best to plausibly resolve a contradiction of his own making, Galileo explained that he had reread his book during his recent period of solitary confinement in his apartment.

Not having seen it for so long, I found it almost a new book by another author. I freely confess that it appeared to me in several places to be written in such a way that a reader, ignorant of my intention, would have reason to believe that the arguments for the wrong side, which I intended to confute, were so expressed that they meant to carry conviction rather than be easily refuted. My error, I confess, had been one of vainglorious ambition, pure ignorance, and inadvertence.

Galileo asked the court “to take into consideration my pitiable state of bodily indisposition, to which, at the age of 70 years, I have been reduced by ten months of constant mental anxiety and the fatigue of a long and toilsome journey at the most inclement season, together with the loss of the greater part of the years of which, from my previous condition of health, I had the prospect.” In short, hadn’t he suffered enough?

For a while, it seemed the Inquisition might be inclined to agree. Galileo was remanded to the care of the Florentine embassy once again while the final verdict and punishment were being deliberated. He was allowed to go out for drives in the embassy’s carriage, allowed to go for walks in its gardens. Riccardi and Maculano pushed for the most lenient possible handling of the case. But Pope Urban wasn’t quite done toying with his catch. He ordered that Galileo be made to grovel in the most visible possible way before he received his lenient sentence. His doing so would prove a point about Urban’s own authority to everyone, not least to Galileo’s patron Ferdinando II and the rest of his Medici clan.

On May 22, 1633, Galileo entered a hall in the building that houses the library of the Italian parliament today. Waiting for him there were no fewer than seven cardinals. The old man went down on his knees to hear the Inquisition’s judgment and his sentence. He was guilty, of course. His book was to be placed on the Index of Forbidden Books. Every extant copy was to be destroyed, and its author was to be sent to prison for an “indeterminate” length of time. Galileo trembled when he heard this last, but he made no attempt to argue against it. This proud man who had always so relished triumphing at a public debate stood and placed both hands upon the Holy Bible to acknowledge that he was beaten in this one.

I curse and detest the said errors and heresies, and generally all and every error, heresy, and sect contrary to the Holy Catholic Church. And I swear that in the future I will neither say nor assert orally or in writing such things as may bring upon me similar suspicion. If I know any heretic, or one suspected of heresy, I will denounce him to this Holy Office, or to the Inquisitor and Ordinary of the place in which I may be. I also swear and promise to adopt and observe entirely all the penances that have been or may be imposed on me by this Holy Office. And if I contravene any of these said promises, protestations, or oaths — which God forbid! — I submit myself to all the pains and penalties which by the sacred canons and other decrees general and particular are imposed and promulgated against such offenders. So help me God and the Holy Gospels, which I touch with my own hands.

Legend has it that, as he stepped away from the dais on which the Bible rested, Galileo muttered the words Eppur si muove under his breath: “And yet it moves!” But there is no reason to believe he really did so. He had lost this fight, and at the end of the day he was a pragmatist, not a martyr. The most we might reasonably assume is that he thought something like those famous words to himself. For he was also enough of a scientist to know that everyone — even these stubborn men of the Church — would be forced to accept the physical reality of a peripatetic Earth before too many more years went by.

The announced sentence of life imprisonment had been one last twist of the psychological knife on the part of Urban, as even Galileo may have more than half suspected. The next day, he received a commutation: he was to be sent to live as a monk in a monastery instead of being kept in a prison cell. He was moved to Siena, whose archbishop was charged with arranging this. But his sympathizers continued to lobby Pope Urban on his behalf, and on July 3, while Galileo was still in Siena proper, Urban agreed to commute his sentence again. Now he was merely to be held under house arrest. In practice, he lived as the archbishop of Siena’s honored guest, the latter being one more man of the Church who hadn’t relished Galileo’s treatment by the Inquisition. There were almost certainly more such men than there were on Pope Urban’s side of the issue, if an accurate poll could have been taken.

Other friends descended upon Galileo’s study in his Tuscan villa, to remove and burn any documents that might cut against his sworn testimony that he had written his Dialogue to advocate against heliocentrism. This service to the man would prove a disservice to history, in that much of what was burnt would doubtless have made for fascinating reading today.

In December of 1633, Galileo received his third and last commutation, when he was allowed to return to his villa, although he would still be technically considered under house arrest for the remainder of his life. He never wrote or spoke again about the fundamental structure of the cosmos — and who can blame him? And yet he did enjoy something of a second wind as a scientist, discovering, probably as much to his own surprise as anyone else’s, that he had one last book left in him. In Two New Sciences, he reintroduced Salviati, Simplicio, and Sagredo, his trio of Socratic debaters from the Dialogue. This time, however, the two sciences they debated were that of materials and motion, the core of classical physics. Hearkening back many decades to his experiments throwing objects off the top of the Leaning Tower of Pisa, Galileo produced what is, taken in terms of pure science, divorced from its cultural implications, arguably his most important single work of all, rivaled only by The Starry Messenger. Although the cast of characters was the same, the new book had none of the polemical quality of the Dialogue. Instead of being a simpleton straw man, Simplicio was now a debater to be reckoned with, raising pertinent questions that deserved an airing even if he was still largely in the wrong in Galileo’s view.

When Two New Sciences was finished, Galileo knew better than to seek permission to publish it from the Church. Friends carried the manuscript up to the city of Leiden in the Protestant Netherlands for printing. At least 50 copies of the unauthorized book made it down to Rome during Galileo’s lifetime, causing his supporters and defenders there some more sleepless nights. But Pope Urban was beset by other problems, and showed no interest in taking up the fight again. And anyway, there was little or nothing about the content of this book that went against Church doctrine, only the bare fact of its unauthorized publication by a Protestant press.

Even as the book was coming off the press in 1638, Galileo was entering the final phase of his life. While he was putting the finishing touches on his crowning scientific achievement, his eyesight had begun to fail in ways that were beyond the power of any pair of spectacles to correct. A year later, he was all but blind, a cruelly ironic fate for a man who had first become famous thanks to the telescopes that let him see farther than anyone ever had before.

Galileo Galilei passed away on January 8, 1642, at the age of 77 years. There was no grand public funeral for this man who had died under house arrest, still a heretic in the eyes of the Church, if a (nominally) repentant one. His body was deposited in an unmarked grave beneath an undistinguished corridor in Florence’s Basilica of the Holy Cross. Pope Urban, now an elderly man himself with barely two years left to live, issued no public comment on the passing of the physicist and astronomer.

Notwithstanding that it took place quietly in back rooms and concluded with nothing so dramatic as a burning at the stake, the trial of Galileo for heresy is widely considered one of the more shameful and embarrassing events in the long history of the Catholic Church. As time marched on and science and religion became more and more hopelessly at odds with one another in the opinion of many, it became a handy cudgel for secularists to wield against the faithful, a sort of fable about how organized religion will always end up stifling free thought and trying to win the argument by fiat and threats when it can’t do so in any other way. And make no mistake, there is something to this point of view. The bitter, ultimately futile battle which Pope Urban waged against heliocentrism was just the first of a lengthy succession of such read-guard actions, all of which Christianity was destined to lose as its “God of the gaps” in human knowledge was inexorably whittled away by the steady march of progress.

And yet, as soon as we look harder at the actual circumstances surrounding Galileo’s trial, the picture becomes muddier. The case for Galileo as the unblemished hero of the story is of course complicated by the fact that he did lose his nerve and repent in the end, as well as by the gaps in his own case for heliocentrism, which made it harder for reasonable people to accept than it might have been if he had bothered to engage with the work of Johannes Kepler. Even more importantly, the traditional telling ignores how uncomfortable even many of those inside the Catholic Church were made by the determination of Pope Urban to prosecute Galileo. More than some allegorical contrast between the proverbial man of reason and the man of faith, the episode reflects the vanities and prejudices of one very particular pope. Even history’s fables tend to wind up being situational when you take the time to examine them more closely.

Although it would take the Church until 1979 to formally apologize for its treatment of Galileo, it did little more to enforce its ban on heliocentrism after Pope Urban went to his grave in 1644. In 1673, a priest at the Basilica of the Holy Cross dared to place a plaque to mark the location of Galileo’s heretofore unmarked grave. In 1737, Galileo’s remains were dug up and transferred to a grand mausoleum inside the same basilica. That is to say, a branch of the same Catholic Church that officially regarded him as a repentant but still disgraced heretic went to considerable expense to honor and celebrate his memory. Never underestimate the ability of human beings or human institutions to maintain two contradictory viewpoints at the same time. Sometimes it’s the only way to muddle through.

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