THE name of Galileo has long enjoyed a remarkable celebrity. And yet, strange to say, the common appreciation of his character rests upon a misconception of his real claims to distinction. His name is associated in the minds of most persons with great astronomical discoveries, and the decision of the question regarding the true system of the universe. But in these respects he holds only a secondary position. His true claim to greatness rests upon his discoveries as a natural philosopher and as the founder of the science of dynamics. Galileo's astronomical discoveries, such as those of the satellites of Jupiter and of the phases of Venus, are indeed brilliant. But they required no genius, and are such as might have been made by any person of ordinary ability possessed of the command of a good telescope, and an attentive habit of observation. On the other hand, his physical and mechanical discoveries were such as could only proceed from a superior mind. Accordingly we find him evincing extreme jealousy regarding the first, in which he felt he might meet with many competitors; whereas in the latter he stands alone and without a rival. Such is the opinion expressed by Lagrange in his Mecanique Analytique. "This science (dynamics)," he says, "is due entirely to the moderns, and it was Galileo who laid the first foundations of it. This discovery (of the laws of falling bodies) did not indeed procure for him in his lifetime as much celebrity as those which he had made in the heavens; but it forms now the most solid and real part of the glory of this great man."* Arago, in his Biographical Notices, forms a similar appreciation of the discoveries of Galileo in astronomy.

* Lagrange, Mecanique, p. 207.

"Without intending," he says, "to lessen their just claims to the admiration and surprise which they excited at the time, we are bound, from a due regard to truth, to say that the rapidity with which they succeeded one another was nothing astonishing. It would have required only a few hours to make all the observations made by Galileo during the years 1610 and 1611."

The astronomer Delambre, in his Histoire de l'Astronomie Moderne, speaks as follows of the astronomical discoveries of Galileo: "Galileo shows, indeed, in his Livre des Dialogues, the superiority of the hypothesis of Copernicus over that of Ptolemy. But how much greater effect would he have given to his assertion, if he had said that the remedies against the opposite errors, which he says are to be found in the system of Copernicus, had been set forth by Kepler; if he had done for the discoveries of a contemporary what he has done for his own? His discoveries have, indeed, removed some difficulties and done away with some objections which would sooner or later have answered themselves, whereas the ideas of Kepler have essentially ameliorated the whole system by laying down the true foundations of planetary astronomy. It is truly inconceivable that Galileo should not in a single place have made the least mention of those far more difficult discoveries which finally led Newton to discover the general cause which forms the soul of that mechanism first established by Kepler." "Chance," he remarks in another place, "led to the discovery of the telescope in Belgium. Galileo received an account of it, and by the next day he had made one for himself, which magnified three times. He perfected it a little, and discov

ered spots on the sun; he saw also the phases of Venus and the satellites of Jupiter. This was useful and brilliant; but was it difficult? Compare these three discoveries with the three laws of Kepler."

Galileo's true claims, then, to celebrity rest upon his discoveries in mechanics. His position as an astronomer has been unduly exaggerated. It is the common impression that the question regarding the true system of the universe remained undecided until his time, and that it was he who definitively decided it. This, we have seen, is false. The true system of the world had been already proved and solidly established by Copernicus and Kepler. The discoveries of Galileo served opportunely to confirm what had already become known from other sources. They have furnished science with no new principle, and the proofs which he has supplied can bear no comparison in point of strength and power with those already advanced by his two illustrious predecessors.

is that it fails to satisfy any of the experimental laws of the phenomenon."

The interest attaching to the name of Galileo is connected in the minds of many with the position which he holds in respect of the relation of science to religion. He represents in his person, as they suppose, the advance of science struggling against the persecution of the Church. How erroneous is this idea will be best seen by a short review of Galileo's life and of the circumstances which led ultimately to the condemnation of his doctrines by the Sacred Congregation.

Galileo Galilei, of Florentine extraction, was born at Pisa on the 8th of February, 1564. On the 5th of November, 1581, he entered on the study of natural philosophy and medicine in the university of that city, and here first showed the strong bent of his mind towards mechanical inquiry. It was at this time, according to some writers, that Galileo was led, by observing accidentally the oscillation of a lamp suspended from the roof of the cathedral, to the discovery of the principle of the isochronous movement of the pendulum, destined to prove hereafter productive of so many important consequences for the measurement of time. In 1585 he came to Florence to follow a course of mathematics. In 1589, in his twenty-fifth year, he was called by the Grand Duke of Tuscany to the chair of Professor of Mathematics in the University of Pisa, at the recommendation of the Cardinal del Monte. He did not, however, remain long at Pisa. His discoveries in mechanics, such as those which resulted in the establishment of the laws of falling bodies, struck a blow at the peripatetic doctrines of motion. He thus found himself in direct opposition to the teaching of the schools, in which the philosophy of Aristotle had long been dominant. An outburst of indignation, in which his own scholars

Others, again, suppose that Galileo at least established the movement of the earth by direct proof. But this, also, is a mistake. The physical proofs which establish by sensible evidence the movement of the earth, as, for instance, by the movement of the pendulum, are of quite recent date. There is not one of the observations of Galileo which goes to prove the fact. The only proof which he did bring forward, and on which he greatly prided himself, was singularly unhappy. This was the proof drawn from the phenomenon of the tides. For this phenemenon is completely independent of the movement of the earth. It is due solely, as is now ascertained, to the combined action of the sun and moon upon the waters of the ocean. M. Arago says of this theory advanced by Galileo, that "it is unworthy of the author to whom we are indebted for the true principles of modern mechanics, and that its least defect

joined, was raised against him. Galileo fled before the storm, gaining at the same time a wider field by obtaining from the Republic of Venice the place of Professor of Mathematics, in 1591, in the University of Padua, which he continued to hold till 1606. By some writers Galileo's retirement to Padua is ascribed to his injudicious censure and needlessly public exposure of the defects of a piece of machinery contrived by John de Medicis, natural son of Cosmo I, de Medicis, and subjected to his criticism. order of banishment, it is said, was the penalty of his imprudence and want of judgment.

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It was during his stay in Padua that he published the greater part of the works which have given celebrity to his name. Here, as at Pisa, he continued to make active researches in mechanics and natural philosophy, and brought both reasoning and experiment to bear, though with but little consideration for the prejudices of his opponents, upon the received doctrines of the schools. He also openly declared himself in favor of the ancient opinion held by Pythagoras concerning the movement of the earth, revived in the preceding century by Copernicus, and supported at this time with great distinction by Kepler. What was the common opinion at the time on this point, and how was it regarded by the Church? The greater part of the body of professors and learned men believed, with the mass of the people, the system of Ptolemy; a few more gifted minds maintained the system of the world taught by Pythagoras, and which had been in general lost sight of during the Middle Ages, though perhaps some traces of it had been kept alive in the schools of Bologna. The Church left the discussion of the question perfectly free. There had been sovereign pontiffs, cardinals, and priests who had even supported and defended the doctrine of Pythagoras.

Nicolas de Cusa, born in 1401, and created cardinal by Pope Eugenius IV in 1448, was the first who had revived the old doctrine, and published in 1435 his work De docta Ignorantia, dedicated to Cardinal Cesarini, in which he maintains the movement of the earth around the sun. He was followed by Copernicus, who, born in 1473 at Thorn, at that time under Poland, studied in Italy, entered holy orders, became canon, and was appointed in 1500 Professor of Mathematics at Rome. It was in this character that he was consulted in 1512 by the Council of Lateran in the work of the reform of the Calendar, completed seventy years later by Pope Gregory XIII. The opinion maintained by Copernicus had found supporters; and in 1533 John Albert Widmanstadt, a German, explained it in Rome in the presence of Pope Clement VII, the Cardinals Orsini and Salviati, the Bishop of Viterbo, and the physician Matthew Corte. The Pope listened with pleasure to the explanation, and, as a mark of his satisfaction, appointed Widmanstadt one of his secretaries, and presented him with a Greek manuscript, which is preserved in the library at Munich, with an inscription on one of the pages recording the circumstances of the gift. Ten years after this séance at the Vatican, Copernicus was prevailed upon, much against his will, by the Cardinal Schomberg and by the Bishop of Culm, to publish his treatise De Revolutionibus Orbium Celestium, a work on which he had been employed for more than thirtyfive years. The work was dedicated to the learned Pontiff Pope Paul III, who was engaged in a correspondence with Calcagnini, the first Italian who publicly supported the system of Copernicus. It is well known what a spirit of faith and piety animated the elevated researches of Kepler.

The Church, then, it will be seen from these few facts, so far from thwarting the progress of science, en

couraged it, so long as it confined itself within its own legitimate bounds, and avoided the introduction and the discussion of theological questions. Galileo, like his friend Kepler, embraced at an early period the opinion in favor of the earth's motion. In a letter dated May 30th, 1597, he declared plainly that he regarded the opinion of Pythagoras as much more probable than that of Aristotle. Kepler having sent him his work published in 1596, Galileo told him in answer that he should read it with great pleasure, for that he had already for many years adopted the doctrine. He added that he should himself have added a number of demonstrations and proofs in support of it, were he not afraid of sharing the fate of Copernicus; "for if Copernicus," he says, "has gained with some undying fame, he is with numberless persons an object of raillery and contempt."*

It was not, then, the Church that Galileo was afraid of, but public opinion. Copernicus had received the support of the Sovereign Pontiff; but the new doctrine, though it might be favorably received by a few minds of a higher order, would be rejected by the great body of professors and learned men. This enables us to see the famous decree of 1616 in its true light; it shows what was the general opinion at the time regarding the doctrine of Copernicus.

To return to Galileo at Padua. The telescope, the principle of which, as we mentioned above, recently discovered in Holland, and in a manner rediscovered and at once applied by the Tuscan astronomer in Italy, opened to him new fields of discovery beyond all, according to the expression of M. Biot, that the imagination could conceive. Galileo gave a report of his discoveries in a work which he published in 1610, entitled Nuntius Sidereus, and in which he pointed out their bearing upon the system of the rotation of the earth. * Op. di Galileo, vol. vi, p. 11. Florence, 1842-56.

The work was received with great applause throughout Europe. The Grand Duke of Tuscany, who had already been flattered by the compliment paid him by Galileo in naming the newly discovered satellites of Jupiter the Stars of Medici, and who had on this account, it is said, recalled him to Florence, conferred on him the title of first Professor of Mathematics and Philosophy, securing to him at the same time leisure to continue his researches by leaving him unincumbered with the charge of teaching. The King of France requested as a favor that the first star he should discover should be named Bourbon. Kepler publicly acknowledged his appreciation of the sublimity of genius manifested by Galileo, and printed the work at Prague with a preface by his own hand. It raised, however, on the other hand, serious attacks from his opponents. The members of the Universities of Pisa and Padua, and all the favorers of the Peripatetic school, rose in a body against it.

This hostility to Galileo owed its origin in a great measure to the very advance which he made in science. His mechanical and astronomical discoveries struck a fatal blow at the Aristotelic doctrine almost universally received at the time in the schools. The system which regarded the earth as the centre of the universe, and immovable in the heavens; which fixed the stars and planets in material and transparent spheres, to which alone they owed their motion; which recognized no change in the heavens except in the sublunary space, that is to say, in the portion of the heavens between the earth and the moon -was shaken to its centre by the discoveries which tended to confirm with accumulated proofs the hypothesis of the earth's rotation, with the rest of the planets, around the sun.

Galileo's naturally impetuous character, which, not satisfied with establishing the truth of his own discov

eries, led him unnecessarily to expose and triumph over the errors of his opponents, increased the exasperation of the attacks against him. His enemies gladly availed themselves of any arguments which could be brought to bear upon him with the greatest effect.

Galileo and his friends turned their eyes to Rome, where, though they had reason to expect much opposition from the learned, they still looked with confidence for an impartial judgment. Any one who really knows Rome is aware thatnot to speak of the caution, prudence, and gentleness, which so naturally belong to its tribunals-the dominant tone among its highest circles is always one of indulgence, forbearance, and liberality. But every great system has its Tadpoles and Tapers, the men who live upon gossip picked up third or fourth hand from the eavesdroppers of some anti-camera, and who are never so happy as when they have the opportunity of hinting at some probable exercise of the Church's severity, or at the imagined disfavor which has fallen on some illustrious Catholic. These men usually find a goodly number of very un-Roman friends of Rome in various quarters to propagate the mischief which they have initiated. It is therefore almost surprising that the air should not have been so filled with sinister reports as to shake the well-grounded confidence of Galileo. Father Clavius wrote to him on December 17th, 1610, that he had himself on several occasions seen the new planets he had discovered, and added that he was entitled to great credit for having been the first to observe them. .Strengthened by such support, Galileo set out for Rome on the 23d of March, 1611. He was warmly received by Prince Cesi, founder of the Academy of the Lyncei, and the Cardinal del Monte, and he entertained sanguine hopes, from his communications with several learned and distinguished

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persons, that before his departure he should see his discoveries generally recognized.* He was received with distinction by Paul V. Cardinal Bellarmine consulted the Jesuit Fathers, the astronomers of the Roman College, regarding Galileo's observations upon the fixed stars, the milky way, the character of Saturn, the phases of Venus, the inequalities on the moon's surface, and the satellites of Jupiter. Fathers Clavius, Griemberger, Malcozzo, and Lembo returned a favorable reply. The omission of Galileo's name in the inquiry only shows that the matter was a scientific, and not a personal, question.

Galileo might, then, be well satisfied with his stay in Rome. The Cardinal Farnese, after having received Galileo at his table in Rome, entertained him at his magnificent villa at Caprarola, and Cardinal Maffei Barberini, afterwards Urban VIII, who had already celebrated his discoveries in verse, addressed to him, amongst many affectionate letters, a note dated October 11th, 1611, in which he says, "Valuable men such as you deserve to live long for the public benefit." Galileo had thus obtained entire success in this visit to Rome. But things were not so in Florence, where a jealous party had gathered round the Archbishop. An attempt was made, though without effect, to induce a priest to protest in the pulpit against the "extravagances" of Galileo. This was the first symptom of opposition. His enemies were trying their strength.

In the following year, 1612, Galileo published his Discorso sui Gallegianti, in which he paid compliments to many of the distinguished persons in Rome, and received encouraging replies from the Cardinals Maffei Barberini, Bellarmine, and Conti. Galileo, who was already uneasy at the complaints of his opponents, had inquired of Cardinal Conti whether

* Opere di Galileo, vol. vi, p. 47.