5. The Great Ptolemaic Smackdown: Here's Mud in Yer Eye

Previously on the Smackdown...

1. For sound empirical reasons the consensus science of 1400 years had been that the Earth is stationary at the bottom of the world and the Church Fathers anciently interpreted Scripture in the light of this settled science.
2. In the early 1600s, a series of telescopic discoveries made nearly simultaneously by Harriot, the Fabricii, Marius, Galileo, Scheiner, Lembo, et al., had broken Ptolemaic astronomy beyond repair.  But falsifying Ptolemy does not affirm Copernicus.  The Tychonic model seemed the best alternative at the time.  After all, if a geomobile theory were factual, it would require an entirely new physics, and no one had one handy.
3. One discovery -- the sunspots -- triggered a flamewar of epic proportions between Fr. Christoph Scheiner SJ, a mathematician in Ingolstadt, and Galileo Galilei, a mathematician-courtier of the Florentine Grand Duke. This will have Dire Consequences later. 
4. Die-hard Aristotelian Lodovico delle Colombe attacks the new discoveries in a paper, some philosophers refuse to look through a telescope, some look but see nothing.(*)  Galileo ignores or mocks them.  Then della Colombe's "Liga" engineers a series of attacks, first by Lorini, then more scandalously by Caccini, finally by a formal complaint filed by Lorini with the Holy Office.  The Office dismisses the complaint without prejudice.  
   
   (*) see nothing.  With good reason.  The first telescopes did not produce great images. 

 Curses, foiled again.

In today's episode....

Holy Office HQ

20 Mar 1615.  The day before the Holy Office closes out Lorini's complaint, Caccini (remember him?) calls on Cardinal Michaelangelo Seghizzi, Commissary of the Holy Office, and testifies that "Florence is full of Galileists," saying things like "God is a sensitive being that can laugh and weep."  (Galileo had said exactly the opposite, and pointed to such Biblical passages as evidence that Scripture is not always scientifically literal.)  Caccini sez Galileo "holds Scripture of lowest importance," and that he is "in correspondence with Germans"! (code-talk for "Lutherans."  Can we say "Kepler"?)  Galileo also holds two propositions that everyone knows are "scientifically false and absurd" and are "at odds with Scripture."  The inquisitor nods and says, Got any proof of this?  Lorini told me; he's got a letter you should read.  (The inquisitor already has.)  Under cross-examination, Caccini begins to backtrack.  You ever meet this Galileo?  Uh,  no.  But others have.  Yeah?  Like who?  Umm. Ferdinando Ximenes O.P. -- plus one Gianozzo Attavanti, who upheld Galileo.  Describe them.  Descriptions follow.  Witness dismissed. (De Santillana, p. 49)

(*) Caccini.  After Tommaso's infamous sermon, his brother Matteo, who lived in Rome, wrote him in outrage (2 Jan 1615), telling him "you have behaved like a dreadful fool."  The text of the letter is here. 

 Caccini had come Rome because his brother Matt wangled him a Resident Bachelor of Arts at the Minerva as a way of dragging him away from Florence and his involvement with those "nasty pigeons" (i.e., Della Colombe's Liga.)   Matt wrote their older brother Alex in January that Tom is "lighter than a leaf and emptier than a pumpkin" and that he has "ways to have him removed out of Italy ifnecessary."

Degrees of Kevin Bacon: The elder Caccini brother, Allesandro, had made his early career in the banking interests controlled by Fillipo Salviati, Galileo's BFF and sponsor who will play one of the roles in the Dialogue.  In Rome, he had gone into horticulture and helped shape the Villa Borghese park. 

21 Mar. 1615.  Cardinal Piero Dini (44) and Giovanni Ciampoli (26) write to Galileo telling him that they have sussed out the Zeitgeist and found no great moves afoot, only the usual rumors one finds in Rome at any time.  Cardinals Maffeo Barberini (47) and Francisco del Monte likewise send assurances through them, as does the sympathetic Fr. Luigi Maraffi, Preacher-General of the Dominicans.(*)  Caccini has come to Rome only for a baccalaureate of his. 

(*) The Tuscan clan.  All these men, plus Bellarmino and Galileo, are Tuscans, owing political allegiance to the Grand Duke.  At this point only Bellarmino knows that Caccini has filed a complaint, and it is not yet on the docket.  Nothing may come of it.  (The interrogatories will not be finished until November.)  So no one is being coy.  The Office operates in strict confidentiality.  But there is an undercurrent of anti-Tuscan prejudice among the Romans in the Curia.  We think they are all Italians.  They did not. 

Mug shot of Galileo

23 Mar. 1615.  Galileo has heard that Copenicanism might be ruled as acceptable as a simple mathematical system.  This might please the mathematicians, but not Galileo.  He sends a spiritual defense of his views to Dini, rejecting the notion that the Copernican model is "just math."  He includes an authentic copy of Letter to Castelli, but as it was written in haste, he adds that he is working on an expanded version as Dini has urged him to.  Copernicanism must be accepted outright (despite no convincing demonstration being yet available!) or rejected outright.  This is a dangerous line to draw in the sand, since the empirical evidence is against Copernicanism at this point, and the model is in fact wrong.(*)  Ciampoli warns him that "not everyone has the dispassionate faculty... one man amplifies, the next one alters, and what came from the author's own mouth becomes so transformed in spreading that he will no longer recognize it as his own."  Dini and Ciampoli do not show this letter around and advise Galileo not to test the enemy's fortifications when no war has yet been declared.  But Galileo is no pacifist.

(*) the model is in fact wrong.  Recall that the Copernican model had more epicycles than the Ptolemaic one, that (for mystical reasons) the planets moved in perfect Platonic circles, and that the centers of these orbs were not actually the Sun but the center of the Earth's orbit.  A viable scientific theory is not just  a fluffy-bunnies-and-rainbows notion.You could flip a coin and get a mobile Earth!

The model.  Notice how much simpler the Copernican model is.  Not!  Nor did it provide notably superior predictions for horoscopes and calendar-making, which were the two reasons for astronomical mathematics.  The centers of planetary orbits in the Copernican model are indicated by the red dots.  Notice that they are a) not all the same, b) not actually at the sun and c) some of them move on their very own epicycles! 

2 Apr. 1615.  The Holy Office tells the Florentine Inquisitor -- what today is called an "investigating magistrate" (Continental law) or a "district attorney/prosecutor" (in the US) -- to interview the witnesses Caccini tagged.  The Florentine Inquisitor shows no great hurry for doing so.  Ximenes is traveling and cannot be located.  And who is this Attavanti? 

12 April 1615.  Carmelite priest Paolo Foscarini had written a book (see previous episode) defending Copernicanism and explaining how the Scriptures could be read contrary to the Church Fathers.  In the context of the times, this personal Scripture-interpreting sounds an awful lot like Martin Luther, and Cardinal Roberto Bellarmino (now 73 and ailing) has to remind him that he is not in fact a theologian, saying inter alia:

Card. Bellarmino

"[I]f there were a true demonstration that the sun was in the center of the universe and the earth in the third sphere, and that the sun did not travel around the earth but the earth circled the sun, then it would be necessary to proceed with great caution in explaining the passages of Scripture which seemed contrary, and we would rather have to say that we did not understand them than to say that something was false which has been demonstrated.  But I do not believe that there is any such demonstration; none has been shown to me.  It is not the same thing to show that the appearances are saved by assuming that the sun really is in the center and the earth in the heavens.  I believe that the one demonstration might exist, but I have grave doubts about the other, and in a case of doubt, one may not depart from the Scriptures as explained by the holy Fathers." [emph. added]  (Letter to Foscarini)

Notice: "may not depart from the Scriptures as explained by the holy Fathers" not "may not depart from the Scriptures as literal."  Bellarmino was aware that no text is self-explanatory; it must be interpreted.  The Fathers had read things in the light of the rock-solid consensus science.  If anyone ever comes up with, like, you know, empirical proof? that the Earth moves, then we'll take another look at how to understand those passages.  Meanwhile, let's not be hasty either to approve or condemn.  Bellarmino does not know Copernicus.  Very few people in Europe have actually read Copernicus!  (Even many of those who champion geomobility do so more in reaction to what they see as hidebound Aristotelianism.)  But Bellarmino does not dismiss him as "that fool" as Luther had done. 

It seems strange to our modern obsessions, but Bellarmino (and others) did not regard astronomical mathematics as the single most important thing in life. 

TOF pauses at this point on what is to Modern eyes a fascinating and paradoxical irony.  In his Letter to Foscarini, Bellarmino shows himself to understand scientific proof better than Galileo.  In his Letter to Castelli, Galileo shows himself to understand exegesis better than Bellarmino.  Go figure.   

Matt Barbarini

Galileo agrees that Scripture is inspired and that there cannot be two truths.  He doesn't want the Church to back herself into a corner on a matter of astronomy.  But for his friends Bellarmino and Cardinal Maffeo Barberini (47) of the Congregation of the Index the question of truth does not arise in the case of astronomical models because they are simply tools for calculation.  Galileo OTOH believes the Earth really does move.  If he'd had proof of this, all would have been well.  But he does not, and he never will.

TOF pauses once more to note that the real Scientific Revolution in astronomy was to move astronomy from a branch of mathematics to a branch of physics.  Galileo intuited from his study of the Moon that the heavenly bodies were physical places much like Earth, about which physical discoveries could be made.  Some other telescopists have been reaching the same conclusion, but to most folks the old instrumentalist approach remains the default, and cosmological models (whether Ptolemy, Copernicus, or Tycho) remain merely calculation devices.  Hence, the Lutheran Andy Osiander's well-meant preface to Copernicus' book.  

Sidelines.  Kepler is distracted from astronomy by the fact that his old battle-axe of a mother has been accused of witchcraft! 

Ursula Reinbold, a neighbor and ex-BFF of Katharina Kepler, accuses Mrs. Kepler of having poisoned her with a magic potion following a business dispute. Later in 1615 the local magistrate (a cousin of Reinbold) will get drunk and try to force Mrs. Kepler at sword-point to admit that she is a witch.  Mrs. Kepler then brings a civil suit for slander against the Reinbold family.  After which the situation spirals out of control.  The matter will not be finally resolved until October, 1621.  (Christie (2012)  What to do if your mother's a witch)

Another sideline: Dutch mathematicus Willebrord Snel (of refraction law fame) actually determines a meridian degree of arc using triangulation.  The method of triangulation had been devised in 1533 by mathematicus Gemma Frisius, who was (happily enough) a Frisian.  This method made it possible, by surveying, to accurately determine the distance between two widely separated geographical positions.  A tremendous boon to matters astronomical.  (Christie (2013) Getting the measure of the earth.)

May 1615.  In early May, Foscarini leaves Rome, having befriended Cdl. Giovanni Millini, Secretary of the Holy Office.

16 May 1615.  Confident that Galileo will show restraint, Cardinal Dini tells him to come to Rome and "be welcomed by everyone, because I have been told that many Jesuits secretly share your position, although they remain silent."  (Remember: the Order had told its teachers to stick to strict Aristotelianism and keep out of any controversies with the Dominicans.)

Galileo's correspondence for the next several months is lost.

Philosophical Stehpunkt.

De Santillana pauses in his account to discuss why the Aristotelians found the whole matter foolish and absurd.  In the pagan science that the muslims and medievals had inherited, the universe was sorta kinda like an organism; and just as every organ in an organism has a place -- heart here, spleen there -- everything in the universe has a proper place where it achieves its full realization.  In such a universe, the shifting of place is only one sort of motion.  Growing, shrinking, changes of quality or aspect are all motions.  An apple ripening into redness is in motion.  A tiger cub maturing is in motion.  It is also a universe in which things come-to-be, "where the word 'realization' has a meaning, whereas in a purely mechanical universe it has none;

"for it is axiomatic in the Cartesian conception that inert matter only, barely, manages to subsist, identical to itself by God's decree. ...  We ought to see, then, why the Aristotelian found it absurd to look just in that most blind and uncouth of events, the fall of [inanimate] matter for a mathematical clarity that he knew he could not find in the so much more important process of the growth of a living being."  (De Santillana, p. 60-61)

Mathematics applies only to the static and accomplished -- such as a quartz crystal.  But the natural world is in constant motion and mathematics does not apply to change.  (Remember: there is no calculus yet.  Only arithmetic and geometry.  Even Newton will carefully structure his Principia in correct Aristotelian form -- with axioms, Euclidean geometry, and deductive logic -- to ensure that is true scientia.  What seems obvious in hindsight never is in situ.

OK, the Florentine inquisitor has now had enough time to track down Ximenes and call him in for testimony.  (Think 'grand jury' without the jury.) Let's get back to the action. 
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13 Nov. 1615.  Seven-plus months after being told, Florentine DA finally interviews Ximenes, who testifies that yes there was this awful scandal caused by the Gallileists.  Who were they? Umm.  Ximenes does not know very well, but there was this parish priest Attavanti who said, oh, terrible things.  What did he say?  He said that God is an accident and there is no substance of things or continuous quality, but everything is a discrete quantity composed of vacua; that God is sensitive: He laughs and weeps.  When and where had he heard such things?  From Attavanti, in the monastery of S. Maria Novella.  But they were probably not his opinions, but this fellow Galileo's.  Witness dismissed. (De Santillana, p. 50)

14 Nov. 1615.  Attavanti is called in and questioned.  Father Ximenes and I were practicing disputation for our theses.  I held the contrary part.  We had taken the section on absolutes of Aquinas' Contra Gentes, where these questions occur.  Ximenes will tell you.  This other man must have eavesdropped and misunderstood.  Another time, as I was telling Ximenes about the motion of the earth, he came in from the next room screaming that this was heretical and he was going to deliver a sermon about it, as he later did.  How long have you known Caccini?  I never even knew his name until afterward.  Do you know Galileo?  Yes, we talked about philosophical matters like the motion of the earth.  But what do you know of his theological opinions?  He must be a very good Catholic or the Grand Duke would not keep him around. Witness dismissed. (De Santillana, p. 50-51)

The testimony is sent to Rome, where it is reviewed and... dismissed as an obvious set-up job.  Attavanti is a dupe being used by Caccini and Ximenes.  Better luck next time, Pigeon Leaguers!  

TOF notices that when Attavanti mentions the motion of the earth, the Inquisitor passes over it and asks the important stuff: what about the theology?  Under the rules of the Inquisition, a charge must be confirmed by two independent witnesses, but things that Caccini said were not repeated by Ximenes, and Ximenes had brought up points not charged by Caccini; so the Inquisitor drops them and asks Attavanti only about God being an accident (versus essence) and about God being sensitive, the only two specifications made by both Caccini and Ximenes.  No one brings up the motion of the earth except Attavanti in passing.  Because the proceedings are secret, Galileo never knows that he has been denounced and the charges dismissed. 

25 Nov. 1615.  A notation on the file reads: "See the Letter on the Sunspots by the said Galileo."  Hmmm.  Maybe things are not yet quite settled.  Curiosity has been aroused. 

28 Nov. 1615.  As a courtier, Galileo is not allowed to leave Florence without the Grand Duke's permission; but having gotten wind of something brewing, Galileo asks for and receives permission to go to Rome and defend his reputation. 

5 Dec. 1615.  The Tuscan ambassador in Rome worries.  "I do not know if (Galileo) has changed his theories or his disposition" but certain Dominicans are ill-disposed and "this is no place to come and argue about the moon."

10 Dec. 1615 -- 20 Feb. 1616.  Galileo arrives in Rome for the third time and dives into a round of parties and receptions -- at which his savage wit excels.  His enemies had spread rumors that he was in disgrace in Florence, but here he comes with the Grand Duke's blessing and staying in the Villa Medici "with board for himself, a secretary, a valet, and a mule."  The mule, TOF supposes, had separate quarters.  But persuading friends at social gatherings is a far cry from persuading the powers-that-be.  It's like a politician with a fawning press.  It is too easy to grow more confident than circumstances warrant. 

Slide from Shea & Artigas

"Lest we misunderstand the historical situation, we must bear in mind that Galileo, whom we celebrate as the Father of the scientific revolution had already entered his fifty-third year without having published the great Copernican book that he had advertised as forthcoming in 1610. His reputation rested on his telescopic discoveries, admittedly brilliant but due in large part to the availability of good lenses in the Venetian Republic. He had seen new things sooner and perhaps a little better than others, but this was due to an optical tube rather than any mastery of optics, about which he knew little. He was undoubtedly a versatile writer and an entertaining speaker, but professionals considered him a gifted amateur when it came to philosophy. There was no indication that he was a particularly good teacher, and he never lectured at the University of Pisa, where his colleagues complained that he was overpaid. Furthermore, he had no training whatsoever in theology. He had been asked, very politely, to prove that the Earth really moved before demanding that the Church reinterpret the Scriptures. Instead of making a gesture to comply, he had become increasingly annoyed at what seemed to him the pig-headedness of the academic world. Galileo was getting restive and felt that he could carry the day if he were allowed to use his tongue instead of his pen. This is why he had to go to Rome. He felt this was the only honourable course, and he believed that it was also in the best interest of the Church. Cardinals Robert Bellarmine and Maffeo Barberini declared that Copernicus had proposed his theory as pure speculation. But they were wrong, as Galileo was anxious to let them know." (Shea & Artigas)

20 Jan. 1616.  "You would be delighted to hear Galileo argue, as he often does, in the midst of some fifteen or twenty persons who attack him vigorously, now in one house, now in another. But he is so well buttressed that he laughs them off; and although the novelty of his opinion leaves people unpersuaded, yet he shows that most of the arguments with which his opponents try to overthrow him, are spurious. Monday in particular, in the house of Federico Ghislieri, he performed marvelous feats. What I liked most was that, before answering objections, he improved on them and added even better ones, so that, when he demolished them, his opponents looked all the more ridiculous."  (Letter: Antonio Querengo to Alessandro d’Este)

That's the way to win friends...


Shea and Artigas add: "Galileo’s eloquence and his brilliant repartees made for great sport in the literary circles to which he was repeatedly invited, but the applause that he won had little to do with a genuine understanding of the nature of the argument. Most people enjoyed the liveliness of the discussion but treated the whole matter as a suitable topic for a debating society rather than a serious scientific enquiry."  Galileo thought he was making great progress, but he was only being entertaining at parties.  The upshot is that he began to Attract Attention.

19 Feb. 1616.  The Holy Office decides to submit to a panel of eleven experts two propositions:

1. "The Sun is at the center of the world and hence immovable of local motion."
2. "The Earth is not the center of the world, nor immovable, but moves according to the whole of itself, also with a diurnal motion."  (i.e. the Earth itself is moving around the sun, and it is also spinning once per day.)

22 Feb. 1616.  Tom Caccini pays a visit on Galileo and makes fulsome apologies for his sermon but impresses Galileo as "a mind full of venom."  It is possible that he was told by the Inquisition to go apologize over the imputation of grievous heresy and blasphemy concerning the nature of God.  And maybe to find out if he still holds that Copernican nonsense.

24 Feb. 1616.  The consultants ("Qualifiers") meet on the 23rd and the following day make their recommendations:

1. The notion that the Sun is at the center of the world and at rest is "foolish and absurd in philosophy, and formally heretical, inasmuch as it expressly contradicts the doctrine of the Holy Scripture in many passages, both in their literal meaning and according to the general interpretation of the Fathers and Doctors"
2. The statement that that the Earth moves "deserves the same censure in philosophy and, as regards theological truth, is at least erroneous in faith."

Reminder: The main reasons why the motions of the Earth are "absurd in philosophy" is that if the Earth revolves around the Sun there would be visible stellar parallax, and if the Earth rotated on its axis there would be Coriolis effects.  There were none, thus falsifying the theory that the Earth moves.  (There were also other reasons that seemed important because no one had formulated a theory of inertia and so forth.)  We can hardly blame the theologians for taking the word of the natural philosophers any more than we could blame the lawyers in the Dover case for taking the word of the biologists.

25 Feb. 1616.  But no board of theologians, even those basing their ruling on Settled Science™, can declare a heresy, even a formal heresy (i.e., heretical in form).  Lord Cardinal Mellini notifies the Reverend Fathers, the Assessor, and the Commissary of the Holy Office that the censure of the Qualifiers has been reported, and His Holiness [Paul V] directs Lord Cardinal Bellarmino to summon before him the said Galileo and inform him of the decree.  If he resists, Galileo is to be presented with an injunction that includes imprisonment. 

Pope Paul V is inclined to declare the hypothesis as contrary to faith, "but the Cardinals Caetani and Maffeo Barbarini withstood the Pope openly and and checked him with the good reasons they gave.  The decree makes a careful distinction between a mathematical hypothesis and a physical fact and it is only the latter that is to be avoided. 

26 Feb. 1616.  Galileo is called in by Cardinal Bellarmino and, in the presence of Michelangelo Segizi O.P., Commissary-General of the Holy Office and two guests, is given a heads-up regarding the forthcoming decree and warned of the error of his opinion.  And immediately thereafter, the Commissary jumps in with the injunction and tells him "to relinquish altogether the theory that the Sun is at the center of the world and at rest and that the Earth moves; nor henceforth to hold, teach, or defend it in any way whatsoever, verbally or in writing." Otherwise proceedings would be taken against him by the Holy Office.  Galileo acquiesces and promises to obey.

Something is wrong.   The injunction was to be delivered only if Galileo rebuffed Bellarmino, whose notification was necessary and sufficient juridical action.  Commissary Segizi jumped the gun.  There are no legal grounds for the personal prohibition against holding "in any manner."  The decree allows for the discussion of Copernicanism as a mathematical hypothesis, since Copernicus' book is only to be corrected and not removed altogether.  The decree does not mention Galileo personally, and some pains have been taken to keep him out of it.  This is a private meeting in advance of a public ruling of the Index, done as a courtesy to Galileo so that he will not be taken by surprise next week.  

When injunctions are issued by the Holy Office, the accused is supposed to sign with his own hand, the signature authenticated by a notary, and the whole countersigned by the Officials.  Instead, "we have only... an administrative minute, unsigned, casually transcribed."  No official witnesses are mentioned, but only two members of the Cardinal's household who were unqualified to understand or bear witness to Inquisitorial proceedings.  There is no official cognizance of the injunction in the documents.  The injunction itself is written into a convenient blank space on the back side of another document, and no one will mention it until the trial of 1633.  De Santillana, no friend of the Church, holds that this minute was fabricated and inserted in the file only years later.  (De Santillana, pp 128-131)

1 Mar. 1616.  The Congregation of the Index -- five Cardinals, including Maffeo Barberini -- meet in Bellarmino’s office.  They recommend that the works they had been asked to judge -- those by Copernicus, Foscarini, and de Zuñiga -- be censured, but not exactly in the terms that had been proposed by the Qualifiers.  At Cardinal Barberini’s request, Copernicanism is not described as “heretical,” but only as false and contrary to the Scriptures. While the books of Foscarini and de Zuñiga are to be suppressed -- both make specifically Scriptural arguments -- Copernicus’ De Revolutionibus is only to be taken out of circulation until corrections are made.  Galileo is not mentioned.  (Shea/Artigas)

[The decree] was, in the eyes of those who prepared and approved it, a prudential decision to remove from public circulation works that might lead unwary readers to misunderstand the nature of science and the role of Scripture. The Counter Reformation did not encourage discussion or debates about doctrinal matters. The theological pendulum that the reformers had pushed too far in one direction was now made to swing to the other extreme, but even the most conservative cardinals would not have considered a decree of the Congregation of the Index as offering a definitive statement of the Catholic faith.  (Shea/Artigas)

5 Mar. 1616.  The decree of the Index is published.  Castelli, friends in Venice, and elsewhere  *facepalm or even *headdesk.  Fortunately, Copernicanism, while it cannot be taught now as established fact, can still be discussed as a mathematical model.  And Bellarmino has stated that if empirical proof is ever made that geomobility really is physical fact, the cognizant bodies can revisit the interpretive issues in the light of new knowledge rather than "say that something was false which has been demonstrated."

6 Mar. 1616. Galileo writes to Curzio Picchena, the Tuscan Secretary of State, saying that he had not written the week before because nothing had happened. 

Pope Paul V

11 Mar. 1616.  Galileo is given a private audience with Pope Paul V and for three-quarters of an hour he and the Pope stroll about the gardens.  When Galileo mentions the actions of his enemies, the Pope assures him that he “could feel safe,” for he was held in such esteem by himself and the whole Congregation that they would not listen to these calumnies.

Paul V Borghese is an authoritarian martinet, a literal, rigid mind, and a man "so averse to anything intellectual that everyone has to play dense and ignorant to be in his favor."  He would never have shown Galileo such favor if the mathematician had been under an injunction by the Holy Office.  

Galileo stays on in Rome because he doesn't want it to look as if he had been whupped out of town.  Cardinal Del Monte writes to the Grand Duke that "Galileo has come out of this in excellent position," and he wants His Highness to know because Galileo's enemies "will not desist from their machinations."  Cesi writes of the Pigeon League, "Let them bark in vain."  Galileo himself writes in great confidence, not as one in terror of the Inquisition or as one enjoined from ever mentioning Copernicanism in any way.

Also he has learned by now from his well-connected friend G.F. Buonamici* that his own Letter to the Grand Duchess, the expanded version of his Letter to Castelli, has been a factor in the last minute compromise by which his BFF Barberini forestalled the Pope from an ill-considered action! 

(*) friend G.F. Buonamici.  Since buonamici means "good friend," the Higher Critics of a future era will undoubtedly claim that he is a fictional contruct introduced into the legend.  Yet we have his diary.  Go figure. 

20 Apr. 1616.  Rumors are circulating that he had been summoned to Rome and charged with heresy.  Castelli writes from Pisa of stories that he had secretly abjured his errors before Cardinal Bellarmino. Three days later, his friend Giovanfrancesco Sagredo reports that the same gossip had rumbled through Venice.

26 May 1616.  Galileo goes to Bellarmino and asks for a certificate clearing him of any taint.  The Cardinal willingly obliges:

We, Robert Cardinal Bellarmino, having heard that it is calumniously reported that Signor Galileo Galilei has in our hand abjured and has also been punished with salutary penance, and being requested to state the truth as to this, declare that the said Galileo has not abjured, either in our hand, or the hand of any other person here in Rome, or anywhere else so far as we know, any opinion or doctrine held by him. Neither has any salutary penance been imposed on him; but that only the declaration made by the Holy Father and published by the Sacred Congregation of the Index was notified to him, which says that the doctrine attributed to Copernicus that the Earth moves around the Sun and that the Sun is stationary at the centre of the world and does not move from east to west, is contrary to the Holy Scriptures, and therefore cannot be defended or held. In witness whereof we have written and subscribed the present document with our own hand this twenty-sixth day of May 1616.

Galileo returns to Florence figuring he has come off pretty well.  With Bellarmino's memo in his pocket, he holds himself free, like anyone else, to discuss Copernicanism as a mathematical model and awaits the revised edition of Copernicus as an approved textbook.  The corrections required are few and minor; simply a matter of not asserting physical fact as proven.  All he has to do now is whump up a book that will demonstrate with certainty the physical reality of the Earth’s dual motion.  Then he hit a snag. 

He didn’t have such a demonstration. 

Then opportunity knocked. 

Part 6.  Comet Chameleon...

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References

1. Bellarmino, Roberto (1615) Letter to Foscarini
2. Christie, Thony (2012) What to do if your mother's a witch.
3. Christie, Thony (2013) Galileo not admitting he was wrong
4. Christie, Thony (2013) Getting the measure of the earth.
5. De Santillana, Giorgio. The Crime of Galileo. Chicago: University of Chicago Press, 1955.
6. The Galilean Library.  Non-Intellectual Contexts.  
7. The Galileo Project.  Chronology.  
8. Linder, Douglas.  The Trial of Galileo.
9. Rowland, Wade. Galileo's Mistake. New York: Arcade Publishing, 2003.
10. Sant, Joseph (2012). Jesuits and the Early Telescope: Scheiner and Grienberger.
11. Shea, William R. & Mariano Artigas. Galileo in Rome. Oxford: Oxford University Press, 2003.
12. Shea, William R. & Mariano Artigas.  The Galileo Affair.  A short summary of #11, with slides.