Dini also warned again, in the same vein: "One may write freely as long as one keeps out of the Sacristy." 28
Galileo answered these admonitions in a letter to Dini dated 23 March. His answer was to refuse any compromise on the Copernican system. Copernicus did not mean it to be understood merely as a hypothesis. It was to be accepted or rejected absolutely. He agreed that the reinterpretation of Holy Scripture in the light of Copernicus should be left to the theologians, but he cannot help it if he has been forced on theological ground, and since Bellarmine had quoted Psalm 19 to Dini, the passage that the sun "rejoiceth as a strong man to run his course", Galileo "in all humility" undertook to refute Bellarmine's interpretation of the Psalm. "The running of the course" refers to the light and heat from the sun, not to the sun itself, etc., etc. 29 Dini probably had the wisdom not to show this to the greatest theologian alive.
The next utterance came from Bellarmine himself. It was a precise and authoritative statement of his attitude, and in view of his position as Consultor of the Holy Office, Master of Controversial Questions, etc., it amounted to an unofficial definition of the Church's attitude to Copernicus. The statement was occasioned by Father Foscarini's book advocating the Copernican system, and couched in the form of a letter of acknowledgement; but it was clearly addressed to Galileo as well, whose name is expressly mentioned. The letter is dated 4 April, 1615; my italics.
"My Very Reverend Father,
It has been a pleasure to me to read the Italian letter and the Latin paper you sent me. I thank you for both the one and the other, and I may tell you that I found them replete with skill and learning. As you ask for my opinion, I will give it as briefly as possible because, at the moment I have very little time for writing.
First, I say it seems to me that your Reverence and Signor Galileo act prudently when you content yourselves with speaking hypothetically and not absolutely, as I have always understood that Copernicus spoke. For to say that the assumption that the Earth moves and the Sun stands still saves all the celestial appearances better than do eccentrics and epicycles * is to speak with excellent good sense and to run no risk whatever. Such a manner of speaking suffices for a mathematician. But to want to affirm that the Sun, in very truth, is at the centre of the universe and only rotates on its axis without travelling from east to west, and that the Earth is situated in the third sphere and revolves very swiftly around the Sun, is a very dangerous attitude and one calculated not only to arouse all Scholastic philosophers and theologians but also to injure our holy faith by contradicting the Scriptures...
____________________
*
He evidently refers here to those epicycles which were needed in the Ptolemaic system to explain the apparent retrogression of the planets and which Copernicus dispensed with.
Second, I say that, as you know, the Council of Trent forbids the interpretation of the Scriptures in a way contrary to the common agreement of the holy Fathers. Now if your Reverence will read, not merely the Fathers, but modern commentators on Genesis, the Psalms, Ecclesiastes, and Joshua, you will discover that all agree in interpreting them literally as teaching that the Sun is in the heavens and revolves round the Earth with immense speed and that the Earth is very distant from the heavens, at the centre of the universe, and motionless. Consider, then, in your prudence, whether the Church can support that the Scriptures should be interpreted in a manner contrary to that of the holy Fathers and of all modern commentators, both Latin and Greek...
Third, I say that, if there were a real proof that the Sun is in the centre of the universe, that the Earth is in the third sphere, and that the Sun does not go round the Earth but the Earth round the Sun, then we should have to proceed with great circumspection in explaining passages of Scripture which appear to teach the contrary, and we should rather have to say that we did not understand them than declare an opinion to be false which is proved to be true. But I do not think there is any such proof since none has been shown to me. To demonstrate that the appearances are saved by assuming the sun at the centre and the earth in the heavens is not the same thing as to demonstrate that in fact the sun is in the centre and the earth in the heavens. I believe that the first demonstration may exist, but I have very grave doubts about the second; and in case of doubt one may not abandon the Holy Scriptures as expounded by the holy Fathers..." 30
The italicized passage under the first heading states clearly that it is admissible not only to expound the Copernican system, but also to say that as a hypothesis it is superior to Ptolemy's. This is "to speak with excellent good sense" so long as we remain in the domain of hypothesis. Under the second heading he paraphrases the legislative decision of the Council of Trent against interpreting Scripture in ways contrary to tradition (directed, of course, not against Copernicus but Luther). Under the third heading the condition is stated which would justify an exception to this rule being made; to wit, that the new cosmology should be "really proven" (or "truly demonstrated"). Since no proof has been shown to him, he has "grave doubts" whether such proof exists; and in case of doubt the request for reinterpreting the Bible must be rejected. He had consulted Grienberger, and Grienberger must have truthfully informed him that no physical proof for the earth's motion had been adduced. He may have added that the absence of stellar parallax and the nine epicycles ascribed to the earth alone, were rather in the nature of a disproof.
Bellarmine had placed the burden of proof for the Copernican system back where it belonged: on the advocates of the system. There were only two possibilities left to Galileo: either to supply the required proof, or to agree that the Copernican system should be treated, for the time being, as a working hypothesis. Bellarmine had, in a tactful way, reopened the door to this compromise in the opening sentence of his letter, where he pretended that Galileo had "contented himself with speaking hypothetically and not absolutely", had praised his prudence, and acted as if the Letters to Castelli and the Grand Duchess, which were before the Inquisition, did not exist.
But Galileo was by now beyond listening to reason. For, by accepting the compromise, he would disclose to the world that he had no proof, and would be "laughed out of court". Therefore he must reject it. It was not enough to be allowed, and even encouraged, to teach the superiority of the Copernican over the Ptolemaic hypothesis. He must insist that the Church endorse it, or reject it, absolutely – even at the risk of the latter alternative, which Bellarmine's letter, Dini's and Ciàmpoli's warnings must have made clear to him.
But how can he motivate his rejection of compromise? How can he refuse to produce proof and at the same time demand that the matter should be treated as if proven? The solution of the dilemma was to pretend that he had the proof, but to refuse to produce it, on the grounds that his opponents were too stupid, anyway, to understand. His answer to Bellarmine was contained in a letter written at some date in May to Cardinal Dini (my italics):
"To me, the surest and swiftest way to prove that the position of Copernicus is not contrary to Scripture would be to give a host of proofs that it is true and that the contrary cannot be maintained at all; thus, since no truths can contradict one another, this and the Bible must be perfectly harmonious. But how can I do this, and not be merely wasting my time, when those Peripatetics who must be convinced show themselves incapable of following even the simplest and easiest of arguments? ..." 31
The truly staggering thing in this passage is not its contemptuous arrogance, but the fact that while talking of "Peripatetics" it is in fact aimed at Bellarmine; for it is on him and not on the backwoodsmen, that the decision depends, and it was Bellarmine who had challenged him to produce proof. Earlier in the same letter to Cardinal Dini, he had written:
"Eight days ago I wrote to Your Reverence in reply to yours of the second of May. My answer was very brief, because I then found myself (as now) among doctors and medicines, and much disturbed in body and mind over many th
ings, particularly by seeing no end to these rumours set in motion against me through no fault of mine, and seemingly accepted by those higher up as if I were the originator of these things. Yet for all of me any discussion of the sacred Scripture might have lain dormant forever; no astronomer or scientist who remained within proper bounds has ever got into such things. Yet while I follow the teachings of a book accepted by the Church (sic), there come out against me philosophers quite ignorant of such teachings who tell me that they contain propositions contrary to the faith. So far as possible, I should like to show them that they are mistaken, but my mouth is stopped and I am ordered not to go into the Scriptures. This amounts to saying that Copernicus' book, accepted by the Church, contains heresies and may be preached against by anyone who pleases (sic) while it is forbidden for anyone to get into the controversy and show that it is not contrary to Scripture..."
Galileo's style is again so convincing that one is apt to forget the facts: that Copernicus' book was only "accepted by the Church" with the qualifications that we know; that Caccini, who had preached against it, was reprimanded by the Preacher General of his Order; and that, according to the accepted rules of the game, the scriptural objections could not be refuted on scriptural grounds, only by the scientific proofs which Bellarmine demanded and which Galileo was unable to supply.
After the passage, that I have already quoted, about the stupidity of his opponents, Galileo went on:
"Yet I should not despair of overcoming even this difficulty if I were in a place where I could use my tongue instead of my pen; and if I ever get well again so that I can come to Rome, I shall do so, in the hope of at least showing my affection for the holy Church. My urgent desire on this point is that no decision be made which is not entirely good. Such it would be to declare, under the prodding of an army of malign men who understand nothing of the subject, that Copernicus did not hold the motion of the earth to be a fact of nature, but as an astronomer merely took it to be a convenient hypothesis for explaining the appearances..."
"The army of malign men who understand nothing of the subject" again obviously included Bellarmine, who had written that he had always understood Copernicus to speak "hypothetically and not absolutely".
Perhaps the one genuine sentiment in the letter was Galileo's wish to get to Rome where he could use his "tongue instead of his pen". Early in December he arrived in Rome; the final phase of the battle had begun.
6. The "Secret Weapon"
This time there was no triumphant reception at the Roman College. Father Grienberger sent word that it would be better for Galileo to bring convincing scientific proof in support of Copernicus before trying to adjust Scripture to him. 32 The Tuscan Ambassador in Rome, Guicciardini, had warned Duke Cosmo against Galileo's coming to Rome, and Bellarmine, who foresaw the consequences, had also advised against it. 33 But the Duke had given in to Galileo, and on his instructions Galileo took up quarters at the Villa Medici – then the Tuscan Embassy – "with board for himself, a secretary, a valet and a small mule". 34
I have quoted some samples of Galileo's superb technique in his written polemics. According to his contemporaries, he was even more effective when he used "his tongue instead of his pen". His method was to make a laughing stock of his opponent – in which he invariably succeeded, whether he happened to be in the right or in the wrong. Here is one Roman witness, Monsignor Querengo, describing Galileo in action:
"We have here Signor Galileo who, in gatherings of men of curious mind, often bemuses many concerning the opinion of Copernicus, which he holds for true... He discourses often amid fifteen or twenty guests who make hot assaults upon him, 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 convicts of vanity the greater part of the arguments with which his opponents try to overthrow him. Monday in particular, in the house of Federico Ghisileri, he achieved wonderful feats; and what I liked most was that, before answering the opposing reasons, he amplified them and fortified them himself with new grounds which appeared invincible, so that, in demolishing them subsequently, he made his opponents look all the more ridiculous." 35
It was an excellent method to score a moment's triumph, and make a lifelong enemy. It did not establish his own point, but it destroyed his opponent's. Yet by the force of circumstances, these were the only tactics that he could adopt: to demonstrate the absurdity of Ptolemy's epicycles and to pass in silence over the absurdity of Copernicus' epicycles. The Tuscan Ambassador reported:
"... He is passionately involved in this quarrel, as if it were his own business, and he does not see and sense what it would comport; so that he will be snared in it, and will get himself into danger, together with anyone who seconds him... For he is vehement and is all fixed and impassioned in this affair, so that it is impossible, if you have him around, to escape from his hands. And this is a business which is not a joke but may become of great consequence, and this man is here under our protection and responsibility..." 36
But Galileo could not be persuaded to desist. He had manoeuvred himself into a position from which he could not retreat without loss of face. He had committed himself to an opinion, and he must be proved right; the heliocentric system had become a matter of his personal prestige.
An aggravating factor in the drama was the personality of Paul V Borghese "who abhors the liberal arts and his [Galileo's] kind of mind, and cannot stand these novelties and subtleties", as Guicciardini described him. 37 "Those who understand something and are of curious mind, if they are wise, try to show themselves quite the opposite in order not to fall into suspicion and get into trouble themselves."
Even Bellarmine had incurred Paul's displeasure. He and the other leading dignitaries – Cardinals Barberini, Dini and del Monte, Piccolomini and Maraffi – knew how to treat him. They were anxious to avoid committing the Church to any official decision on the Copernican system, until the astronomers were able to shed more light on it, and to preserve the status quo as defined in Bellarmine's letter, ignoring Galileo's "incursion into the sacristy". But they knew that if the Pope learnt about the scandal, a showdown would be inevitable. That was probably why Bellarmine had advised against Galileo's visit to Rome.
We come to the last episode before the blow fell. Galileo had repeatedly hinted that he had discovered a decisive physical proof of the Copernican theory, but had so far refused to disclose it. When he began to feel that arguing about the miracle of Joshua and the ludicrousness of Ptolemy was no longer of avail, and that his position was becoming impossible, he produced, as a last card, his "conclusive physical proof". It was his theory of the tides.
Seven years earlier, in the Astronomia Nova, Kepler had published his correct explanation of the tides as an effect of the moon's attraction. Galileo dismissed Keplers theory as an astrological superstition, 38 and declared that the tides were a direct consequence of the earth's combined motions which cause the sea to move at a different speed from the land. The theory will be discussed in more detail in the following chapter, pp. 4640-66. It contradicted Galileo's own researches into motion, was a relapse into crude Aristotelian physics, and postulated that there ought to be only one high tide a day, precisely at noon – whereas everybody knew that there were two, and that they were shifting around the clock. 38a The whole idea was in such glaring contradiction to fact, and so absurd as a mechanical theory – the field of Galileo's own immortal achievements – that its conception can only be explained in psychological terms. It is completely out of keeping with his intellectual stature, the method and trend of his thought; it was not a mistake but a delusion.
Armed with his new "secret weapon" (as a modern scholar has called Galileo's theory of the tides 39 ), he now decided to make a direct assault on the Pope. It seems that all of Galileo's friends who had access to the Pope – Cardinals Dini, Barberini, del Monte, etc. – refused to act as intermediaries, for the mission was finally entrusted to Cardinal Alessandro
Orsini, a youth of twenty-two. Galileo wrote down for him his idea of the tides; the sequel is described as follows in Ambassador Guicciardini's report to Duke Cosmo II of Tuscany:
"Galileo has relied more on his own counsel than on that of his friends. The Lord Cardinal del Monte and myself, and also several cardinals from the Holy Office, had tried to persuade him to be quiet and not to go on irritating this issue. If he wanted to hold this Copernican opinion, he was told, let him hold it quietly and not spend so much effort in trying to have others share it. Everyone fears that his coming here may be very prejudicial and that, instead of justifying himself and succeeding, he may end up with an affront.
As he felt people cold toward his intention, after having pestered and wearied several cardinals, he threw himself on the favour of Cardinal Orsini, and extracted to that purpose a warm recommendation from Your Highness. The Cardinal, then, last Wednesday in Consistory, I do not know with what circumspection and prudence, spoke to the Pope on behalf of said Galileo. The Pope told him it would be well if he persuaded him to give up that opinion. Thereupon Orsini replied something, urging the cause, and the Pope cut him short and told him he would refer the business to the Holy Office.
As soon as Orsini had left, His Holiness summoned Bellarmine; and, after brief discussion, they decided that the opinion was erroneous and heretical; and day before yesterday, I hear, they had a Congregation on the matter to have it declared such. Copernicus, and the other authors who wrote on this, shall be amended or corrected or prohibited; I believe that Galileo personally is not going to suffer, because he is prudent and he will feel and desire as the Holy Church does. [March 4]." 40
The Tuscan Ambassador was evidently sorely tried by his guest and ward's antics, and his report is not entirely reliable, because "last Wednesday in Consistory" places the episode on 2 March, whereas the papal decree to summon the theologians of the Holy Office to give a formal opinion on the Copernican theory is dated 19 February. But the confusion about dates may have some trivial explanation; the fact that Orsini, armed with Galileo's "final proof", interceded with the Pope is not disputed; and whether it was this particular incident, or something of a similar kind, which brought matters to a head is not very important. 41 Galileo had done everything in his power to provoke a showdown.