Galileo’s Fame and Pupils.—Wishes to be freed from Academic Duties.—Projected Works.—Call to Court of Tuscany.—This change the source of his Misfortunes.—Letter from Sagredo.—Phases of Venus and Mercury.—The Solar Spots.—Visit to Rome.—Triumphant Reception.—Letter from Cardinal del Monte to Cosmo II.—The Inquisition.—Introduction of Theology into the Scientific Controversy.—“Dianoja Astronomica.”—Intrigues at Florence. Galileo’s fame, especially through his telescopic discoveries, and partly also through the exertions of his noisy opponents, had long extended beyond the narrow bounds of Italy, and the eyes of all central Europe were directed to the great astronomer. Numbers of pupils flocked to him from all countries, so that no lecture room in Padua was large enough to hold them. There were some distinguished personages among them, such as the Archduke Ferdinand of Austria, the Landgrave Philip of Hesse, the princes of Alsace, Mantua, etc., who mostly came to attend the lectures of the versatile master on fortification. It is, however, another fable of over zealous biographers to state that even Gustavus Adolphus, the hero of the thirty years’ war, went to school for some months to Galileo.[57]
This close occupation, with lectures and private lessons of all kinds, took him too much away from his own studies, and after twenty years’ professorship Galileo longed for a post in which he could prosecute his own researches, and devote himself to the completion of his works, free from academic[28] duties. A letter from Padua, even in the spring of 1609,[58] shows his longing for this salaried leisure. But he is aware that the republic can never offer him such a post, “for it would not be suitable to receive a salary from a free state, however generous and magnanimous, without serving the public for it; because if you derive benefit from the public, you have the public to please, and not a mere private person.” He also mentions that he can only hope for such a favour from some absolute sovereign; but it must not be supposed that he wishes for an income without doing anything for it; he was in possession of various inventions, was almost daily making new ones, and should make more if he had the necessary leisure. Galileo adds that it has always been his intention “to offer them to his own sovereign and natural lord before any other, that he may dispose of them and the inventor according to his pleasure; and if it seemed good to his serene highness to accept it, to present him not only with the jewel but with the casket also.”
This first attempt of Galileo’s, however, to gain a footing at the court of Tuscany seems to have been unsuccessful. At any rate in the extant correspondence of this period there is not a word more on the subject; and a few months later, after the construction of the telescope, he thankfully accepted the chair of mathematics at Padua offered to him for life by the republic. But this invention and the consequent discoveries had meanwhile acquired such vast importance, and had, as we have seen, raised such a storm in the whole educated world, that it now appeared very desirable to the court of Tuscany to attach to itself for ever the man on whom the eyes of scientific Europe were fixed.
The first steps towards this end were taken when Galileo went to Florence in the Easter recess of 1610 to show his telescopic discoveries to Cosmo II., especially the stars which[29] bore the name of the reigning house. We afterwards find Galileo entering eagerly into the negotiations which followed. In the letter to Vinta before mentioned, of May 7th, 1610, he presses for a decision, for, he says, observing that day after day goes by, he was determined to set a definite purpose before him in the ordering of the life that may be left to him, and to devote all his powers to perfect the fruits of his previous efforts and studies, from which he might look for some fame. He then mentions the conditions on which he at present serves the republic, perhaps in order that they might be guided by it at Florence; but what he lays most stress on is that it is of the utmost moment to him that leisure should be assured him for the completion of his labours, by his being freed from the obligation to give public lectures; but it will always confer on him the highest honour to give lectures to his sovereign, to whom also he will dedicate all his writings.
The same letter is also of the highest interest as giving us an insight into the scientific projects he was then cherishing. He communicates to the Tuscan secretary of state the works the completion of which lies so near his heart. He says:—
“The works which I have to finish are chiefly two books de systemate, seu constitutione universi, a vast project full of philosophy, astronomy, and geometry; three books de motu locali, an entirely new science, for no other inquirer, ancient or modern, has discovered any of the wonderful phenomena which I show to be present in natural and induced motion; I may therefore with perfect justice call it a new science discovered by me from its first principles; three books on mechanics, two relating to the demonstration of the principles and fundamental propositions, one containing the problems; although others have treated of the same subject, what has been hitherto written upon it is neither as to extent nor in other respects a fourth part of what I am writing. I have also various smaller works in view on matters connected with nature, such as de sono et voce, de visu et coloribus, de maris ?stu, de compositione continui, de animalium motibus, and others. I am also thinking of writing some books for the soldier, not only to cultivate his mind, but to teach him by select instruction all those things connected with mathematics which it would be an advantage to him to[30] know, as, for instance, castrametation, military tactics, fortification, sieges, surveying, estimate of distances, artillery, the use of various instruments, etc.”[59]
We regard with astonishment the wonderful versatility which we find displayed in Galileo’s works. And amongst them are not only all the larger ones announced in the above letter; his important telescopic discoveries and his ceaselessly active mind led him far to surpass the bounds he had set himself, for he was the first to infuse conscious life into the slumbering idea of the Copernican system.
This memorable letter of Galileo’s soon brought the court of Tuscany to a decision. Fourteen days later, 22nd May, Vinta wrote to him, as a preliminary, that the Grand Duke seemed well disposed to recall him to his native country and to grant all his wishes.[60] He promised to inform Galileo as soon as it was all settled. On 5th June he wrote that Cosmo II. was willing to nominate him as first philosopher and mathematician of the University of Pisa, with an annual stipend of 1000 Florentine scudi, without any obligation to live at Pisa or to give lectures. Vinta requested Galileo to let him know whether he agreed to these conditions, in order that he might have the necessary application drawn up in Galileo’s name, as well as the decree and rescript; the time of their publication shall be left to Galileo, and meanwhile all shall be kept secret.[61] Galileo wished particularly that nothing should be known at Venice of these negotiations, which did not place his gratitude to the republic which had shown him so much favour in the best light, until all was decided and therefore irrevocable.
Having declared himself entirely satisfied with the proposed conditions, in a letter to the secretary of state, the[31] only alteration being that he should like not only to be first mathematician at Pisa, but also first mathematician and philosopher to the Grand Duke himself,[62] the decree summoning him to the court of Tuscany in this twofold capacity was issued on 12th July, 1610.
Notwithstanding all the great advantages which this new post secured to him, it was a very bad exchange for Galileo from the free republican soil to the doubtful protection of a princely house which, although very well disposed towards him, could never offer so decided an opposition to the Roman curia as the republic of Venice. It was indeed the first step which precipitated Galileo’s fate.[63] In the Venetian republic full liberty of doctrine was really enjoyed, in religious Tuscany it was only nominal. In Venice politics and science were secure from Jesuitical intrigues; for when Pope Paul V. thought proper to place the contumacious republic under an interdict in April, 1606, the Jesuit fathers had been compelled to quit the soil of Venice “for ever.”[64] In Tuscany, on the contrary, where they felt quite at home, their influence weighed heavily on everything affecting their own interests, and especially therefore on politics and science. Had Galileo never left the pure, wholesome air of the free city for the stifling Romish atmosphere of a court, he would have escaped the subsequent persecutions of Rome; for the republic which, not long before, had been undaunted by the papal excommunication of their doge and senate, would assuredly never have given up one of its university professors to the vengeance of the Inquisition.
At the beginning of September, 1610, Galileo, to the no small displeasure of the Paduans, left their university, at which eighteen years before he had found willing reception[32] and support when his longer tarriance at Pisa had become impossible; deserted his noble friends, Fra Paolo Sarpi, Francesco Sagredo, and others; and proceeded to the capital of the court of Tuscany on the lovely banks of the Arno, where at first, it is true, much honour was done him, but where afterwards envy, jealousy, narrowness, ill will, and fanaticism combined together to his destruction. One of his most devoted friends, Francesco Sagredo, foresaw it. When Galileo left Venice he was in the East, in the service of the republic, and did not return till the spring of 1611, when he wrote a remarkable letter to his friend at Florence. After having heartily expressed his regret at not finding Galileo on his return home, he states his doubts about the step his friend had taken. He asks, among other things, “where will he find the same liberty as in the Venetian territory? And notwithstanding all the generous qualities of the young ruler, which permitted the hope that Galileo’s merits will be justly valued, who can promise with any confidence that, if not ruined, he may not be persecuted and disquieted on the surging billows of court life, by the raging storms of envy?” It is evident from another passage in the letter that Galileo’s behaviour had made a bad impression at Venice, where they had not long before raised his salary to a thousand florins, and conferred his professorship on him for life; towards the end of the letter Sagredo lets fall the ominous words that he “was convinced that as Galileo could not regain what he had lost, he would take good care to hold fast what he had gained.”[65]
Only a month after Galileo’s arrival at Florence he made a fresh discovery in astronomy which eventually contributed to confirm the Copernican theory, namely, the varying crescent form of the planet Venus. With this the important objection to the new system seemed to be removed, that Venus and Mercury did not exhibit the same phases of light as the moon, which must be the case if the earth moved, for they would[33] vary with her position in the universe. Galileo communicated this appearance, which entailed conclusions so important, and which he therefore wished to investigate more thoroughly before making it known, to his friend and correspondent Julian de’ Medici at Prague, in an alphabetical enigma, as in the case of the singular appearance of Saturn. It was as follows:
“H?c immatura a me jam frustra leguntur o y.”[66]
Having fully convinced himself by nearly three months’ observations that Venus and Mars exhibited phases similar to those of the moon, he made it known in two letters of 30th December[67] to Father Clavius, at Rome, and to his former distinguished pupil Benedetto Castelli, abbot of the congregation of Monte Cassino, in Brescia; and in a letter of 1st January, 1611, he sent the following solution of the anagram to Julian de’ Medici:—
“Cynthi? figuras ?mulatur mater amorum.”
In this letter he draws the important conclusions, first that none of the planets shine by their own light, and secondly “that necessarily Venus and Mercury revolve round the sun; a circumstance which was surmised of the other planets by Pythagoras, Copernicus, Kepler, and their followers, but which could not be proved by ocular demonstration, as it could now in the case of Venus and Mercury. Kepler and the other Copernicans may now be proud to have judged and philosophised correctly, and it may well excite disgust that they were regarded by the generality of men of book learning as having little understanding and as not much better than fools.”[68]
At this time Galileo was also eagerly occupied with a phenomenon which was to be a further confirmation of the[34] Copernican view of the universe, the spots on the sun. By attentively observing their motions on the sun’s disk he afterwards discovered the sun’s motion on its own axis, a fatal blow to the Ptolemaic system. Although to science it may be quite indifferent whether Galileo, or Fabricius, or the Jesuit father Scheiner first espied the spots on the sun (for they all lay claim to the discovery), for us it has its importance, because the bitter contention between Galileo and Scheiner on the subject materially contributed to set the stone rolling which, in its fall, was no less disastrous to the moral greatness of Galileo than to the erudition of Rome.
In consideration of the intense interest excited by Galileo’s “epoch-making” discoveries, the Roman curia, which still held it to be one of its most important duties to guard mankind as much as possible from precocious knowledge, was of course eager to learn more about them, and above all, of the conclusions which the discoverer drew from them. It must also have appeared of great importance to Galileo to acquaint the Roman savans and dignitaries of the Church with his scientific achievements, for the authority and influence then exercised by them over the free progress of science made their opinions of the utmost moment to him. They must, if possible, be first made to see the premises with their own eyes, that they might afterwards be able to comprehend and assent to the conclusions. Galileo clearly saw this, as appears from a letter of 15th January, 1611, to Vinta[69] (who was then with the court at Pisa), in which he urgently begs permission for a visit to the papal residence. The request was not only immediately granted, but the court placed a litter at his disposal, undertook to defray all his expenses, and directed the Tuscan ambassador at Rome to prepare quarters for him at the embassy and to entertain him during the whole of his stay.[70] Meanwhile, however, Galileo was attacked[35] by an illness which delayed his journey for nearly two months. On 22nd March he received a cordial letter of introduction[71] from Michel Angelo the younger to Cardinal Barberini, afterwards Urban VIII., and on the next day he set out provided with his most convincing arguments, namely several excellent telescopes.
He was received with the greatest honour. His triumphs were really extraordinary, so great that they were sure to secure for him numerous personal enemies in addition to the opponents of his doctrines. He exhibited the oft discussed appearances to cardinals and learned men through the telescope, and, whenever he could, dispelled their doubts by the incontrovertible evidence of their own eyes. People could not refuse to believe this, and Galileo’s success in the papal city was complete. Of still greater importance, however, was the opinion given on 24th April by four scientific authorities of the Roman College, on the character “of the new astronomical discoveries of an excellent astronomer,” at the request of Cardinal Robert Bellarmine. This commission, consisting of the learned fathers Clavius, Griemberger, Malcotio, and Lembo, confirmed what they had long denied and ridiculed, convinced by the evidence of their own senses of the truth of the facts maintained by Galileo.[72] By this opinion of the papal experts his discoveries received, to a certain extent, the sanction of the Church, and became acknowledged truths. The care with which the mention of Galileo’s name is avoided both in the request and the opinion is remarkable.
Attentions of all sorts were heaped upon the astronomer. Pope Paul V. granted him a long audience and graciously assured him of his unalterable good will, which however did not remain quite unaltered in the sequel. The highest dignitaries[36] of the Church testified their admiration; the Accadémia dei Lincei (of the Lynxes), founded six years before by Prince Cesi, made the renowned guest a member; when he took his departure at the beginning of June he left behind him in the metropolis of catholicism as many sincere friends and admirers as envious foes, the fate of all really great men.
A letter from Cardinal del Monte of 31st May, 1611, to Cosmo II., best shows how successful Galileo’s visit to Rome was. He writes with real enthusiasm:—
“Galileo has during his stay at Rome given great satisfaction, and I think he must have felt it no less himself, for he had the opportunity of showing his discoveries so well that to all clever and learned men in this city they seemed no less true and well founded than astonishing. Were we still living under the ancient republic of Rome, I verily believe there would have been a column on the Capitol erected in his honour. It appeared to me to be my duty to accompany his return with this letter, and to bear witness to your Highness of the above, as I feel assured that it will be agreeable to you, since your Highness entertains such gracious good will towards your subjects, and to distinguished men like Galileo.”[73]
But the watchful Inquisition had already directed its attention to the man who had made such portentous discoveries in the heavens. How far this had gone we unfortunately do not exactly know. The only well authenticated indication we possess is the following notice in the protocols of the sittings of the Holy Congregation: “Feria iii. die, 17 Maii, 1611. Videatur an in Processu Doctoris C?saris Cremonini sit nominatus Galilaeus Philosophi? ac Mathematic? Professor.”[74] This is the first time that the name of Galileo occurs in the papers of the Congregation of the Holy Office, and it was in the midst of the applause which greeted him in the eternal city. Whether, and in what way, this official query was answered is not to be found in the documents of the Inquisition. But it looks ominous that there should be an inquiry about a connection between[37] Galileo and Cremonini who was undergoing a trial. The causes and course of the trial of Cremonini by the Inquisition are not yet known. All that is known is that he was Professor of the philosophy of Aristotle at the University of Padua; and it appears from the letters of Sagredo to Galileo, that his lectures and writings had given rise to suspicions of atheism. For the rest, Cremonini was all his life one of Galileo’s most decided enemies.
The very triumphs of Galileo and his telescopic discoveries were the causes, to a great extent, of those ceaseless and relentless persecutions which were to restrict his labours and embitter his life. The Aristotelians perceived with rage and terror the revolutionary discoveries of this dangerous innovator were surely, if slowly, gaining ground. Every one of them, with its inevitable logical consequences, pulled down some important stone in the artistic structure of their views of nature; and unless some measures were taken to arrest the demolition, it was clear that the venerable edifice must fall and bury the inmates beneath the ruins. This must be averted at any price, even at the price of knowledge of the acts of nature. If Galileo’s reformed physics offered no point of attack, his astronomy did; not indeed in the honourable contest of scientific discussion, but by bringing theology into the field against science.
Galileo had never openly proclaimed his adoption of the earth’s double motion, but the demonstration of his telescopic observations alone sufficed to make it one of the burning questions of the day. What were the phases of Venus and Mercury, the motions of the solar spots, and above all Jupiter and his moons, this little world within our large one, as Galileo afterwards called it himself,[75] but telling proofs of the truth of the Copernican theory? The question of the two systems had been hitherto an exclusively scientific one. How else could the famous philosopher and astronomer Nicholas of Casa, who taught the double motion of the earth[38] in the fifteenth century, have gained a cardinal’s hat? How could the German, Widmanstadt, have explained his theory, which was based upon the same principles, to Pope Clement VII. in 1533? How could learned men like Celio Calganini, Wurteis, and others, have given public lectures on the subject in Italy in the second half of the sixteenth century? Neither Casa, however, nor Widmanstadt, Calganini, Wurteis, nor even Copernicus, had ventured openly to declare war with the school of Aristotle, nor to overthrow by the crushing evidence of experiment the dogmas of natural science based upon philosophy and a priori arguments alone. These learned men had been tolerated because they fought with the same weapons as the followers of Ptolemy, logic and philosophy. They did not possess the powerful lever of direct evidence, because they were not acquainted with the telescope. But Galileo, with his fatal system of demonstration by observation of nature, was far too dangerous a foe. Peripateticism was no match for the home thrusts of arguments obvious to the senses, and its defenders were well aware that if they would not yield their position they must call in some other ally than mere science. And they adopted the means best adapted for putting a temporary drag on the wheels of truth, and for ruining Galileo; in order to prop up the failing authority of Aristotle they called in the inviolable authority of Holy Scripture!
This dragging of the Bible into what had previously been a purely scientific controversy, a proceeding which proved so fatal to Galileo, must not however, as has been done by several authors, be attributed solely to party considerations or even personal motives. This is absolutely false. Greatly as these factors were concerned in it, it must be admitted that at first they were only incidentally mixed up with it. The multitude of the learned, who still adhered entirely to the old system of the universe, and regarded the theories of Copernicus (not yet based on ocular demonstration) as mere fantasies, were really aghast at the telescopic discoveries[39] of Galileo which threatened to overturn all their previous beliefs. The learned, and still more the semi-learned, world of Italy felt the ground tremble beneath their feet; and it seemed to them as if the foundations of all physics, mathematics, philosophy, and religion, were, with the authority of Aristotle, which had reigned for two thousand years, being borne to the grave. This did not present itself to them as progress but as sacrilege.
A young fanatic, the monk Sizy (the same who seven years later was broken on the wheel for political crimes at Paris), was the first to transfer what had been a purely scientific discussion to the slippery arena of theology. At the beginning of 1611 he published at Venice a work called “Dianoja Astronomica”[76] in answer to the “Sidereus Nuncius,” in which he asserted that the existence of the moons of Jupiter was incompatible with the doctrines of Holy Scripture. He appropriately dedicated his book to that semi-prince of the blood, John de’ Medici, who was known to be the mortal enemy of Galileo. The author, as we learn from his own work, was one of those contemptible men who carefully abstained from even looking through a telescope, although firmly convinced that the wonders announced by Galileo were not to be seen. Galileo did not vouchsafe to defend himself from this monkish attack any more than from Horky’s libel the year before. He contented himself with writing on the back of the title page of the copy still preserved in the National Library at Florence the following lines from Ariosto:—
“Soggiunse il duca: Non sarebbe onesto
Che io volessi la battaglia torre,
Di quel che m’ offerisco manifesto,
Quando ti piaccia, innanci agli occhi torre.”[77]
[40]
But Galileo’s envious foes at once consorted with the, at all events, honourable fanatics of the old school, and eagerly seized the opportunity of pursuing their miserable designs “to the glory of God and imperilled religion.” It was in Florence itself, in the palace of the Tuscan Archbishop Marzimedici, who had once studied under Galileo at Pisa, that secret consultations were held, presided over by this prelate, how the inconvenient philosopher and his revolutionary system might best be ruined. They even then went so far as to request a preacher to hurl at Galileo from the pulpit the accusation, more dangerous than any other in the sixteenth century, that he was attacking the Bible with his doctrines. But for this time these pious gentlemen had gone to the wrong man, for the priest, seeing through the foul purpose of the commission, declined it.
Galileo had not the slightest knowledge of the secret conspiracy which was plotting against him, and was first roused from the security into which he had been lulled by the brilliant success of his visit to Rome by a letter from his friend there, Cigoli the painter, of 16th December, 1611.[78] But he did not at first attach to these communications the importance they deserved, and it was not until several months afterwards that he addressed himself to Cardinal Conti, who was very friendly to him, to ask how far the Holy Scriptures did really favour the Aristotelian views of the universe, and whether the Copernican system contradicted them.
Conti answered him in a letter of 7th July, 1612,[79] that the statements of Holy Scripture were rather against the Aristotelian principle of the unchangeableness of the heavens than in favour of it, for all the fathers had held the contrary opinion. But the case was different with the doctrine of the earth’s revolution round the sun, as held by the Pythagoreans, Copernicus and others. This certainly did not seem to agree with Holy Scripture, unless it was assumed that it merely[41] adopted the customary mode of expression. But, added the cardinal, that was a method of interpretation to be employed only in case of the greatest necessity. Diego di Zu?iga had indeed explained in this way, conformably with the Copernican opinions, the passage in which Joshua commanded the sun to stand still; but the explanation was not generally admitted.
Father Lorini also, professor of ecclesiastical history at Florence, afterwards a ringleader of the base intrigues against Galileo and an informant against him, wrote to him 5th November, 1612,[80] to deny a report that he had publicly preached against Galileo. He only confessed to having given it as his opinion, in a conversation about the two systems, that the View of this Ipernic, or whatever his name might be, appeared to be contrary to Holy Scripture. Galileo wrote in a letter of 5th January, 1613,[81] to Prince Cesi: “The good man is so well acquainted with the author of these doctrines that he calls him Ipernic. You can see how and by whom poor philosophy suffers.” It appears also from the same letter that Galileo was now well aware of the intrigues being carried on against him in Florence, for he says among other things: “I thank you and all my dear friends very much for your anxiety for my protection against the malice which is constantly seeking to pick quarrels even here, and the more so since the enemy is so near at hand; but as they are but few in number, and their ‘league,’ as they call it among themselves, is but of limited extent, I laugh at it.”