Galileo Galilei and the Roman Curia/Chapter 1

by Karl von Gebler

PART I.

———

GALILEO'S EARLY YEARS, HIS
IMPORTANT DISCOVERIES, AND FIRST CONFLICT
WITH THE ROMAN CURIA.

CHAPTER I.

EARLY YEARS AND FIRST DISCOVERIES.

Birth at Pisa.—Parentage.—His Father's Writings on Music.—Galileo destined to be a Cloth Merchant.—Goes to the Convent of Vallombrosa.—Begins to study Medicine.—Goes to the University of Pisa.—Discovery of the Isochronism of the Pendulum.—Stolen Lessons in Mathematics.—His Hydrostatic Scales.—Professorship at Pisa.—Poor Pay.—The Laws of Motion.—John de' Medici.—Leaves Pisa.—Professorship at Padua.—Writes various Treatises.—The Thermoscope.—Letter to Kepler.—The Copernican System.—"De Revolutionibus Orbium Cœlestium."

The same memorable day is marked by the setting of one of the most brilliant stars in the firmament of art and the rising of another in the sphere of science, which was to enlighten the world with beams of equal splendour. On the 18th February, 1564, Michael Angelo Buonarotti closed his eyes at Rome, and Galileo Galilei first saw the light at Pisa.

He was the son of the Florentine nobleman, Vincenzo Galilei, and of Julia, one of the ancient family of the Ammanati of Pescia, and was born in wedlock, as the documents of the church clearly attest.^[1] His earliest years were spent at Pisa, but his parents soon returned to Florence, which was their settled home. Here he received his early education. His father had distinguished himself by his writings on the theory of music, particularly the mathematical part of it.^[2] They were not merely above mediocrity, but aimed at innovation, and if they did not achieve reform, it was to be attributed to the conservative spirit then reigning in Italy, which asserted itself in every department of life, and especially in the spheres of art and science.

Galileo's father had no property. His income was but scanty, and the fates had endowed him with a numerous family instead of with fortune.^[3] Under these untoward circumstances he at first destined the little Galileo, as is related by Gherardini, his earliest biographer, to a career by no means distinguished, though advantageous in a material point of view, and one that conferred much of their wealth on the Florentines, so that it was held in high esteem—he was to be a cloth dealer. But the young noble first received the education befitting his station, that is, a very mediocre teacher instructed him in the Humanities.^[4] Fortunately for the clever young scholar, he was handed over to the pious brethren of the convent of Vallombrosa for further education. Here he at once made rapid progress. He acquired great facility in the classics. His thorough study of the masterpieces of antiquity was of the greatest advantage to him. He doubtless thereby laid the foundation of the admirable style to which he afterwards, in some measure, owed his brilliant successes.

Galileo had a great variety of talent. Besides ardent pursuit of the solid branches of learning, he had considerable skill in drawing and music, in which he afterwards attained so much perfection that his judgment was highly esteemed, even by great artists.^[5] He played the lute himself with the skill of a master. He also highly appreciated poetry. His later essays on Dante, Orlando Furioso, and Gerusalemme Liberata, as well as the fragment of a play, bear witness to his lively interest in belles lettres. But from his earliest youth he showed the greatest preference for mechanics. He made little machines with an ingenuity and skill which evinced a really unusual talent for such things.^[6]

With these abilities his father must soon have arrived at the conclusion that his son was born for something better than for distributing wool among the people, and resolved to devote him to science; only it was necessary that the branch of it to which he turned his attention should offer a prospect of profit. Medicine was decided on as the most likely to be lucrative, although it may not seem the one most suited to his abilities.

On 5th November, 1581, Galileo, then just seventeen, entered the University of Pisa.^[7] Even here the young medical student's independent ideas and aims made way for themselves. At that time any original ideas and philosophical views not derived from the dogmas of Aristotle were unheard of. All the theories of natural science and philosophy had hitherto been referred to theology. It had been held to be the Alpha and Omega of all human knowledge. But now the period was far advanced in which it was felt to be necessary to cast off the narrow garments fashioned by religion, though at first the will to do so exceeded the power. A stir and ferment agitated men's minds. A period of storm and stress had begun for the study of nature and the philosophical speculation so closely connected with it. Men did not as yet possess energy and ability for direct advance, so they turned with real fanaticism to ancient learning, which, being independent, and not based on religious notions, afforded them satisfaction. Under these circumstances recurrence to the past was real progress.

Unconditional surrender to the ideas of others, entire adoption of opinions, some of which were not too well verified, might suit mediocrity, but it could not suffice for the powerful mind of Galileo, who was striving to find out the truth for himself. The genius of the young student rebelled fiercely against rigid adherence to an antiquated standpoint. To the horror of the followers of Aristotle, who were quite taken aback at such unheard-of audacity, he resolutely attacked in public disputations many oracular dicta of their great master hitherto unquestioned, and this even then made him many enemies, and acquired for him the epithet of "the Wrangler."^[8]

Two circumstances occur during Galileo's student years, which, in their main features, are not without historical foundation, although in detail they bear an anecdotal impress. One, which is characteristic of Galileo's observant eye, shows us the student of nineteen devoutly praying in the Cathedral at Pisa; but he seems to have soon wearied of this occupation, for he dreamily fixed his eye on the Maestro Possenti's beautiful lamp, hanging from an arch, which, in order to light it more readily, had been moved out of its vertical position and then left to itself. The oscillations were at first considerable, became gradually less and less, but notwithstanding the varying distances, they were all performed in the same time, as the young medical student discovered to a nicety by feeling his pulse. The isochronism of the vibrations of the pendulum was discovered!^[9]

The other story refers to Galileo's first mathematical studies. Gherardini relates that he was scarcely acquainted with the elements of mathematics up to his twentieth year, which, by the by, seems almost incredible. But while he was diligently studying medicine at Pisa, the court of Tuscany came there for some months. Among the suite was Ostilio Ricci, governor of the pages, a distinguished mathematician and an old friend of the Galilei family; Galileo, therefore, often visited him. One morning when he was there, Ricci was teaching the pages. Galileo stood shyly at the door of the schoolroom, listening attentively to the lesson; his interest grew greater and greater; he followed the demonstration of the mathematical propositions with bated breath. Strongly attracted by the science almost unknown to him before, as well as by Ricci's method of instruction, he often returned, but always unobserved, and, Euclid in hand, drank deeply, from his uncomfortable concealment, of the streams of fresh knowledge. Mathematics also occupied the greater part of his time in the solitude of his study. But all this did not satisfy his thirst for knowledge. He longed to be himself taught by Ricci. At last he took courage, and, hesitatingly confessing his sins of curiosity to the astonished tutor, he besought him to unveil to him the further mysteries of mathematics, to which Ricci at once consented.

When Galileo's father learnt that his son was devoting himself to Euclid at the expense of Hippocrates and Galen, he did his utmost to divert him from this new, and as it seemed to him, unprofitable study. The science of mathematics was not then held in much esteem, as it led to nothing practical. Its use, as applied to the laws of nature, had scarcely begun to be recognised. But the world-wide mission for which Galileo's genius destined him had been too imperiously marked out by fate for him to be held back by the mere will of any man. Old Vincenzo had to learn the unconquerable power of genius in young Galileo, and to submit to it. The son pursued the studies marked out for him by nature more zealously than ever, and at length obtained leave from his father to bid adieu to medicine and to devote himself exclusively to mathematics and physics.^[10]

The unexpected successes won by the young philosopher in a very short time in the realm of science, soon showed that his course had now been turned into the proper channel. Galileo's father, who, almost crushed with the burden of his family, could with difficulty bear the expense of his son's residence at the University, turned in his perplexity to the beneficence of the reigning Grand Duke, Ferdinand de' Medici, with the request that, in consideration of the distinguished talents and scientific attainments of Galileo, he would grant him one of the forty free places founded for poor students at the University. But even then there were many who were envious of Galileo in consequence of his unusual abilities and his rejection of the traditional authority of Aristotle. They succeeded in inducing the Grand Duke to refuse poor Vincenzo's petition, in consequence of which the young student had to leave the University, after four years' residence, without taking the doctor's degree.^[11]

In spite of these disappointments, Galileo was not deterred, on his return home, from continuing his independent researches into natural phenomena. The most important invention of those times, to which he was led by the works of Archimedes, too little regarded during the Middle Ages, was his hydrostatic scales, about the construction and use of which he wrote a treatise, called "La Bilancetta." This, though afterwards circulated in manuscript copies among his followers and pupils, was not printed until after his death, in 1655.

Galileo now began to be everywhere spoken of in Italy. The discovery of the movement of the pendulum as a measurement of time, the importance of which was increasingly recognised, combined with his novel and intellectual treatment of physics, by which the phenomena of nature were submitted, as far as possible, to direct proof instead of to the a priori reasoning of the Aristotelians, excited much attention in all scientific circles. Distinguished men of learning, like Clavius at Rome, with whom he had become acquainted on his first visit there in 1587,^[12] Michael Coignet at Antwerp, Riccoboni, the Marquis Guidubaldo del Monte, etc., entered into correspondence with him.^[13] Intercourse with the latter, a distinguished mathematician, who took the warmest interest in Galileo's fate, became of the utmost importance to him. It was not merely that to his encouragement he owed the origin of his excellent treatise on the doctrine of centres of gravity, which materially contributed to establish his fame, and even gained for him from Del Monte the name of an "Archimedes of his time," but he first helped him to secure a settled and honourable position in life. By his opportune recommendation in 1589, the professorship of mathematics at the University of Pisa, just become vacant, was conferred on Galileo, with an income of sixty scudi.^[14] It is indicative of the standing of the sciences in those days that, while the professor of medicine had a salary of two thousand scudi, the professor of mathematics had not quite thirty kreuzers^[15] a day. Even for the sixteenth century it was very poor pay. Moreover, in accordance with the usage at the Italian Universities, he was only installed for three years; but in Galileo's needy circumstances, even this little help was very desirable, and his office enabled him to earn a considerable additional income by giving private lessons.

During the time of his professorship at Pisa he made his grand researches into the laws of gravitation, now known under the name of "Galileo's Laws," and wrote as the result of them his great treatise "De Motu Gravium." It then had but a limited circulation in copies, and did not appear in print until two hundred years after his death, in Albèri's "Opere complete di Galileo Galilei." Aristotle, nearly two thousand years before, had raised the statement to the rank of a proposition, that the rate at which a body falls depends on its weight. Up to Galileo's time this doctrine had been generally accepted as true, on the mere word of the old hero of science, although individual physicists, like Varchi in 1544, and Benedetti in 1563, had disputed it, maintaining that bodies of similar density and different weight fall from the same height in an equal space of time. They sought to prove the correctness of this statement by the most acute reasoning, but the idea of experiment did not occur to any one. Galileo, well aware that the touchstone of experiment would discover the vulnerable spot in Aristotelian infallibility, climbed the leaning tower of Pisa, in order thence to prove by experiment, to the discomfiture of the Peripatetic school, the truth of the axiom that the velocity with which a body falls does not depend on its weight but on its density.^[16]

It might have been thought that his opponents would strike sail after this decisive argument. Aristotle, the master, would certainly have yielded to it—but his disciples had attained no such humility. They followed the bold experiments of the young professor with eyes askance and miserable sophistries, and, being unable to meet him with his own weapons of scientific research, they eagerly sought an opportunity of showing the impious and dangerous innovator the door of the aula.

An unforeseen circumstance came all at once to their aid in these designs. An illegitimate son of the half-brother of the reigning Grand Duke,—the relationship was somewhat farfetched, but none the less ominous for Galileo—John de' Medici, took an innocent pleasure in inventing machines, and considered himself a very skilful artifice. This ingenious semi-prince had constructed a monster machine for cleaning the harbour of Leghorn, and proposed that it should be brought into use. But Galileo, who had been commissioned to examine the marvel, declared it to be useless, and, unfortunately, experiment fully confirmed the verdict. Ominous head-shakings were seen among the suite of the deeply mortified inventor. They entered into alliance with the Peripatetic philosophers against their common enemy. There were cabals at court. Galileo, perceiving that his position at Pisa was untenable, voluntarily resigned his professorship before the three years had expired, and migrated for the second time home to Florence.^[17]

His situation was now worse than before, for about this time, 2nd July, 1591, his father died after a short illness, leaving his family in very narrow circumstances. In this distress the Marquis del Monte again appeared as a friend in need. Thanks to his warm recommendation to the Senate of the Republic of Venice, in the autumn of 1592 the professorship of mathematics at the University of Padua, which had become vacant, was bestowed on Galileo for six years.^[18] On 7th December, 1592, he entered on his office with a brilliant opening address, which won the greatest admiration, not only for its profound scientific knowledge, but for its entrancing eloquence.^[19] His lectures soon acquired further fame, and the number of his admirers and the audience who eagerly listened to his, in many respects, novel demonstrations, daily increased.

During his residence at Padua, Galileo displayed an extraordinary and versatile activity. He constructed various machines for the service of the republic, and wrote a number of excellent treatises, intended chiefly for his pupils.^[20] Among the larger works may be mentioned his writings on the laws of motion, on fortification, gnomonics (the making of sundials), mechanics, and on the celestial globe, which attained a wide circulation even in copies, and were some of them printed long afterwards—the one on fortification not until the present century;^[21] others, including the one on gnomonics, are unfortunately lost. On the wide field of inventions two may be specially mentioned, one of which was not fully developed until much later. The first was his proportional circle, which though it had no special importance as illustrative of any principle, had a wide circulation from its various practical uses. Ten years later, in 1606, Galileo published an excellent didactic work on this subject, dedicated to Cosmo de' Medici and in 1607 a polemical one against Balthasar Capra, of Milan, who, in a treatise published in 1607, which was nothing but a plagiarism of Galileo's work disfigured by blunders, gave himself out as the inventor of the instrument. Galileo's reply, in which he first exhibited the polemical dexterity afterwards so much dreaded, excited great attention even in lay circles from its masterly satire.^[22] The other invention was a contrivance by which heat could be more exactly indicated. Over zealous biographers have therefore hastened to claim for their hero the invention of the thermometer, which, however, is not correct, as the instrument, which was not intended to measure the temperature, could not be logically called a thermometer, but a thermoscope, heat indicator. Undoubtedly it prepared the way by which improvers of the thermoscope arrived at the thermometer.^[23]

Before proceeding further with Galileo's researches and discoveries, so far as they fall within our province, it seems important to acquaint ourselves with his views about the Copernican system. From a letter of his to Mazzoni, of 30th May, 1597,^[24] it is clear that he considered the opinions of Pythagoras and Copernicus on the position and motion of the earth to be far more correct than those of Aristotle and Ptolemy. In another letter of 4th August of the same year to Kepler, he thanks him for his work, which he had sent him, on the Mysteries of the Universe,^[25] and writes as follows about the Copernican system:—

"I count myself happy, in the search after truth, to have so great an ally as yourself, and one who is so great a friend of the truth itself. It is really pitiful that there are so few who seek truth, and who do not pursue a perverse method of philosophising. But this is not the place to mourn over the miseries of our times, but to congratulate you on your splendid discoveries in confirmation of truth. I shall read your book to the end, sure of finding much that is excellent in it. I shall do so with the more pleasure, because I have been for many years an adherent of the Copernican system, and it explains to me the causes of many of the appearances of nature which are quite unintelligible on the commonly accepted hypothesis. I have collected many arguments for the purpose of refuting the latter; but I do not venture to bring them to the light of publicity, for fear of sharing the fate of our master, Copernicus, who, although he has earned immortal fame with some, yet with very many (so great is the number of fools) has become an object of ridicule and scorn. I should certainly venture to publish my speculations if there were more people like you. But this not being the case, I refrain from such an undertaking."^[26]

In an answer from Grätz, of 13th October of the same year, Kepler urgently begs him to publish his researches into the Copernican system, advising him to bring them out in Germany if he does not receive permission to do so in Italy.^[27] In spite of this pressing request of his eminent friend, however, Galileo was not to be induced to bring his convictions to the light yet, a hesitation which may not appear very commendable. But if we consider the existing state of science, which condemned the Copernican system as an unheard of and fantastic hypothesis, and the religious incubus which weighed down all knowledge of nature irrespective of religious belief, and if, besides all this, we remember the entire revolution in the sphere both of religion and science involved in the reception of the Copernican system, we shall be more ready to admit that Galileo had good reason to be cautious. The Copernican cause could not be served by mere partisanship, but only by independent fresh researches to prove its correctness, indeed its irrefragability. Nothing but the fulfilment of these conditions formed a justification, either in a scientific or moral point of view, for taking part in overturning the previous views of the universe.

Before the powerful mind of Copernicus ventured to question it, our earth was held to be the centre of the universe, and about it all the rest of the heavenly bodies revolved. There was but one "world," and that was our earth; the whole firmament, infinity, was the fitting frame to the picture, upon which man, as the most perfect being, held a position which was truly sublime. It was an elevating thought that you were on the centre, the only fixed point amidst countless revolving orbs! The narrations in the Bible, and the character of the Christian religion as a whole, fitted this conception exceedingly well; or, more properly speaking, were made to fit it. The creation of man, his fall, the flood, and our second venerable ancestor, Noah, with his ark in which the continuation of races was provided for, the foundation of the Christian religion, the work of redemption;—all this could only lay claim to universal importance so long as the earth was the centre of the universe, the only world. Then all at once a learned man makes the annihilating assertion that our world was not the centre of the universe, but revolved itself, was but an insignificant part of the vast, immeasurable system of worlds. What had become of the favoured status of the earth? And this indefinite number of bodies, equally favoured by nature, were they also the abodes of men? The bare possibility of a number of inhabited worlds could but imperil the first principles of Christian philosophy.

The system of the great Copernicus, however, thanks to the anonymous preface to his famous work, "De Revolutionibus Orbium Cœlestium," had not, up to this time, assumed to be a correct theory, but only a hypothesis, which need not be considered even probable, as it was only intended to facilitate astronomical calculations. We know now that this was a gigantic mistake, that the immortal astronomer had aimed at rectifying the Ptolemaic confusion, and was fully convinced of the correctness of his system; we know that this unprincipled Introduction is by no means to be attributed to Copernicus, but to Andreas Osiander, who took part in publishing this book, which formed so great an epoch in science, and whose anxious soul thereby desired to appease the anticipated wrath of the theologians and philosophers. And we know further that the founder of our present system of the universe, although he handled the first finished copy of his imperishable work when he was dying, was unable to look into it, being already struck by paralysis, and thus never knew of Osiander's weak-minded Introduction, which had prudently not been submitted to him.^[28]

A few days after receiving a copy of the great work of his genius, Copernicus died, on 24th May, 1543; and his system, for which he had been labouring and striving all his life, was, in consequence of Osiander's sacrilegious act, reduced to a simple hypothesis intended to simplify astronomical calculations! As such it did not in the least endanger the faith of the Church. Even Pope Paul III, to whom Copernicus had dedicated his work, received it "with pleasure." In 1566 a second edition appeared at Basle, and still it did not excite any opposition from the Church. It was not till 1616, when it had met with wide acceptance among the learned, when its correctness had been confirmed by fresh facts, and it had begun to be looked upon as true, that the Roman curia felt moved to condemn the work of Copernicus until it had been corrected (donec corrigantur).

Having thus rapidly glanced at the opposition between the Copernican system and the Ptolemaic, which forms the prelude to Galileo's subsequent relations with Rome, we are at liberty to fulfil the task we have set ourselves, namely, to portray "Galileo and the Roman Curia."

1. Compare Nelli, vol. i. pp. 24, 25, and Opere xv. p. 384. The strange mistake, which is without any foundation, that Galileo was an illegitimate child, was set afloat soon after his death by Johann Victor Rossi (Janus Nicius Erythræus) in his "Pinacotheca Illustrium Virorum," Cologne, Amsterdam, 1643-1648, and afterwards carelessly and sometimes maliciously repeated. Salviati has published the marriage certificate of 5th July, 1563, of Vincenzio di Michel Angelo di Giovanni Galilei and Giulia degli Ammanati Pescia.
2. Many of these essays, which have never been printed, are among the valuable unpublished MSS. in the National Library at Florence.
3. Galileo had a younger brother, Michel Angelo, and three sisters, Virginia, Elenor, and Livia. The former married a certain Benedetto Landucci, the latter Taddeo Galetti. Galileo was very kind to his brother and sisters all his life, assisted them in many ways, and even made great sacrifices for their sakes.
4. Nelli, vol. i. pp. 26, 27.
5. Op. xv. (Viviani), p. 330; and Op. vi. p. 18.
6. Op. xv. (Viviani), p. 328.
7. The correctness of this date is indisputable, as according to Nelli, vol. i. p. 29, it was found in the university registers. It is a pity that Alberi, editor of the "Opere complete di Galileo Galilei," Florence, 1842-1856, relied for the date on Viviani, who is often wrong.
8. Op. xv. (Viviani), p. 331; also Jagemann, p. 5.
9. Op. xv, (Viviani), p. 332; also Nelli, vol. ii. pp. 722, 723.
10. Op. xv. (Viviani), p. 334.
11. Nelli, vol. i. pp. 32, 33.
12. That Galileo had been in Rome before 8th January, 1588, a fact hitherto unknown to his biographers, is clear from the letter of that date addressed from Florence to Clavius. (Op. vi. pp. 1-3.)
13. See their letters to Galileo. (Op. viii. pp. 1-13.)
14. About £13.—[Tr.]
15. About 71/4d. 100 kreuzers = the Austrian florin.
16. Op. xv. (Viviani), p. 336; and Nelli, vol i. p. 44.
17. Op. xv. (Viviani), pp. 336, 337; Nelli, vol. i. pp. 46, 47; Venturi, vol i. p. 11.
18. See the decree of installation of 26th Sept. (Op. xv. p. 388.)
19. Op. viii, p. 18; Nelli, vol. i. p. 51.
20. Op. xv. (Viviani), pp. 337 and 389.
21. Published by Venturi, 1818, vol. i. pp. 26-74.
22. Op. xv. (Viviani), pp. 339, 340.
23. Op. xv. (Viviani), pp. 337, 338.
24. Op. ii. pp. 1-6.
25. "Prodromus Dissertationum Cosmographicarum."
26. Op. vi. pp. 11, 12.
27. Op. viii. pp. 21-24.
28. See Humboldt's "Cosmos," vol. ii. pp. 345, 346, and 497-499.