Galileo Galilei and the Roman Curia

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.[7] 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

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 of music, particularly the mathematical part of it.[8] 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.[9] 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.[10] 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

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 by great artists.[11] 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.[12]

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.[13] 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

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 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.”[14]

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![15]

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

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 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.[16]

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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.[17]

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

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 Clavius at Rome, with whom he had become acquainted on his first visit there in 1587,[18] Michael Coignet at Antwerp, Riccoboni, the Marquis Guidubaldo del Monte, etc., entered into correspondence with him.[19] 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.[20] 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[21] 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,

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 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.