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Who said: “God does not care about our mathematical difficulties. He integrates empirically.”
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Thumbnail of Galileo Galilei (source)
Galileo Galilei
(15 Feb 1564 - 8 Jan 1642)

Italian natural philosopher who believed the Earth revolved around the Sun. For this, he was interrogated by the Inquisition, was put on trial, found guilty and sentenced to indefinite imprisonment. For renouncing his former beliefs before the Cardinals that judged him, he was allowed to serve this time instead under house-arrest.


from Famous Men of Science (1889)

Galileo Galilei portrait by Domenico Cresti da Passignano (or Passignani) - upper body
Galileo Galilei
by Domenico Cresti da Passignano (or Passignani) before 1642. (source)

[p.1] “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 splendor. On the 18th of February, 1564, Michael Angelo Buonarotti closed his eyes at Rome, and Galileo Galilei first saw the light at Pisa.”

Thus writes young Karl von Gebler, in the best life of Galileo ever written, his dying contribution to literature. Some other authorities place Galileo’s birth on February 15.

He was the oldest in a family of five children born to Vincenzo Galilei, a Florentine noble, and Giulia Ammanati, who also belonged to an ancient family. Vincenzo wrote learnedly about music, and taught his boy to play on the lute and the organ; but he was poor and life was a struggle. However beneficial poverty may be in the development of character, most of us do not crave it for our children, so Vincenzo decided to place his son where he could earn a comfortable support. Music did not bring money. Galileo therefore should [p.2] become a dealer in cloth; a necessity of life, rather than a luxury.

But the boy soon showed great skill in music, surpassing his father. He excelled in drawing and color, and could have become a noted artist. He loved poetry, and had a decided taste for mechanics, making machines of great ingenuity. It soon became evident that such a lad would not be satisfied to spend his life trading in wool.

He must be educated, but how? The family had moved from Pisa, where there were schools of repute, to Florence. An effort had to be made, by the greatest economy, to prepare Galileo to go back to the Pisan University. He showed great aptitude for Latin and Greek, and at seventeen was ready for Pisa.

For what profession should he study? Not what best suited his tastes, but that in which his father thought he could make money, medicine. Poor Vincenzo! who can blame him that he hated poverty for his brilliant son?

At college, Galileo became an ardent student of philosophy, and because he dared to think for himself, and did not always agree with the teachings of Aristotle, he was called “the wrangler.” Until he was twenty he was scarcely acquainted with the rudiments of mathematics, because his father thought this study was a waste of time for a man who was to become a physician. How many parents make the mistake of bending their children to their own plans, instead of ascertaining what a [p.3] boy or girl can do best in the world, and then fitting him or her for it!

While Galileo was studying medicine in Pisa, boarding with a relative, the court of Tuscany came to the city for a few months. Among the suite was Ostilio Ricci, a distinguished mathematician, and Governor of the Pages of the Grand Ducal Court. He was a friend of the Galilei family, and was pleased to see the bright young son, Galileo. When he taught Euclid, the medical student would stand shyly at the schoolroom door, and listen with intense interest. Soon he began to study mathematics secretly; then begged Ricci to teach him, who gladly consented, till the father forbade it, seeing that Euclid interfered with medicine.

Meantime, the youth of nineteen, kneeling at prayers in the Pisa Cathedral, had dreamily watched a bronze lamp swinging from an arch. The oscillations were at first considerable, but as they grew less and less, Galileo observed that they were all performed in the same time, measuring the time by feeling his pulse. The idea occurred to him that an instrument could be constructed which should mark the rate and variation of the pulse. He began to experiment, and soon invented the pulselogia, which the physicians hailed with great delight. The pendulum was not applied to clocks till a half-century later, but its invention attracted the attention of all scholars.

[p.4]After four years’ residence at Pisa, Vincenzo Galilei appealed to the reigning Grand Duke, Ferdinand de Medici, to grant to his son one of the forty free places founded for poor students, but the request was denied, and Galileo, unable to pay for his doctor’s degree, was obliged to leave the university without it. Already he had learned bitter lessons of privation and disappointment, but youth has a brave heart, and looks ever toward the sunlight.

He went back to his home in Florence to study the works of Archimedes, whom he called his “master,” to write his first essay on his Hydrostatic Balance, and to earn the reputation of a bold inquirer in geometrical and mechanical speculations. The father had now given up all hope of a fortune coming through medicine! Henceforward, the genius which was to shed lustre on his own name, otherwise buried in obscurity, was to have its own bent, and work out its own destiny.

If we are in earnest, a door opens sooner or later; but our own hands usually open it. At twenty-four a door opened to Galileo. Marquis Guidubaldo, a celebrated mathematician, appreciating what the young scientist had done, began a correspondence with him, and a valuable friendship resulted. The marquis asked him to study the position of the centre of gravity in solid bodies. Galileo applied himself to it, and wrote a valuable essay, which waited fifty years for publication. [p.5] Perhaps no person can be really great who has not learned patience, and Galileo had many lessons in this virtue before he died.

Through the influence of the marquis, he was brought to the notice of Ferdinand I., reigning Grand Duke, who appointed him to the mathematical professorship at Pisa. This was a great honor for a young man of twenty-six, one who had been too poor to take his degree. The salary was small, less than a hundred dollars a year; but he earned somewhat by the practice of medicine, by lectures on Dante and other literary subjects, and by lessons to private pupils. Of course, he had little or no leisure; but he thus learned one of the most valuable lessons of life,—to treasure time as though it were gold. How glad his father and mother must have been that their wool projects had come to naught!

The professors at Pisa, with a single exception, Jacopo Mazzoni, in the chair of philosophy, were opposed to the new-comer. They were all disciples of Aristotle, and had not Galileo, when a boy among them, dared to oppose the great Grecian? And now, to make matters worse, he had taken some friends to the top of the Leaning Tower, and had put to the test the belief of two thousand years,—that the rate at which a body falls depends upon its weight. When the different weights fell to the pavement at the foot of the Leaning Tower, at the same time, the learned were astonished. If Aristotle could be wrong in one [p.6] thing, he might in others, and this young man would revolutionize the teaching of the times!

The feeling became so strong against the investigator that after three years at Pisa he resigned. When will the world learn toleration for those whose opinions are different from the popular thought? From Galileo to Darwin we have persecuted the men and women whose views were unlike our own in theology, in science, or in social matters.

Through his friend, the Marquis Guidubaldo, the mathematical professorship at Padua was obtained for Galileo. He was now twenty-nine, and becoming widely known throughout Italy. His father had just died, leaving the whole family, a wife and four children, dependent upon him for support; not a small matter for an ambitious and hard-working professor.

Padua gave the young man cordial welcome. Vincenzo Pinelli, a learned nobleman, who possessed eighty thousand volumes, mentioned him to Tycho Brahe, the great Danish astronomer, as a man whom it would be well to cultivate; but the Dane was too cautious about his own reputation, and did not write Galileo till eight years later, and died the following year.

An associate of Tycho Brahe was wiser than his master, and sent Galileo his new book, “Prodromus Dissertationum Cosmographicum.” A warm letter of thanks went back to the immortal John Kepler, saying: “Many years ago I became a convert to [p.7] the opinions of Copernicus, and by that theory have succeeded in fully explaining many phenomena which on the contrary hypothesis are altogether inexplicable. I have drawn up many arguments and compilations of the opposite opinions, which, however, I have not hitherto dared to publish, fearful of meeting the same fate as our master Copernicus, who, although he has earned for himself immortal fame amongst the few, yet amongst the greater number appears as only worthy of hooting and derision; so great is the number of fools.”

John Kepler, like Galileo, lived a pathetic life. His childhood was spent in the little beer-shop of his wretchedly poor father. At six he had a severe attack of small-pox, and his eyes were permanently weakened. He was put to the plough, but his delicate body could not bear the work. At last, through charity, he became a theological student at Tübingen. But here he began to think for himself, and, probably, would have been obliged to leave the university.

Fortunately for science, he heard some lectures given by Michael Möstlen, famous in mathematics and astronomy. A new world opened to Kepler. He applied himself with all the ardor of youth, and at twenty-two became professor of mathematics at Grätz, in Styria. He was soon driven away from this Catholic stronghold, on account of his Protestant faith. Tycho Brahe heard of his needs, and made him his assistant at Prague, with a salary of seven hundred and fifty dollars a year. This [p.8] seemed regal splendor to the poor astronomer. Now he studied the heavens with hope and delight.

But sorrows soon came. His children died, his wife became insane, and died also. The salary could not be paid, on account of the religious wars which convulsed Germany. He wrote almanacs, took private pupils, and in all ways tried to support his second wife and children, while he studied the heavens year by year, discovering his three great laws. The mathematical calculations for the first law, that the planets move in elliptical orbits round the sun, which is placed at one of the foci, filled seven hundred pages. His “Harmonies of the World” contained his third great law: “The squares of the periodic times of the planets are proportioned to the cubes of their mean distances from the sun.”

Such was his joy when he discovered this law, after seventeen years of labor, that he said, “I have written my book. It will be read; whether in the present age or by posterity matters little. It can wait for its readers. Has not God waited six thousand years for one to contemplate his works?” In a last fruitless attempt to recover twenty-nine thousand florins, owed him by the government, worn out with want and disappointment, he fell ill and died at Ratisbon, leaving thirty-three works, twenty-two volumes in manuscript, and his family in the direst poverty. Such was the man who admired Galileo in his youth, and who stands with him in the admiration of the [p.9] generations that have come and gone since these two men lived and wrote and suffered.

At Padua, Galileo soon attracted great numbers to his class-room. Often a thousand gathered to hear his lectures, and when the hall was too cramped, he spoke to the people in the open air. He was above the middle height, well proportioned, with cheerful countenance, witty in conversation, and enthusiastic in his manner. So learned that he could repeat by heart much of the works of Virgil, Ovid, Horace, and Seneca; he was yet modest and unassuming, saying that he never met a man so ignorant but that something might be learned from him.

He labored incessantly. He wrote treatises on Fortifications, on Mechanics, on Gnomonics, on the laws of motion, on the celestial globe, which were copied by his pupils, and sent by them far and wide over Europe. He took a workman into his family, and began to superintend the making of the compass which he had invented, and the thermoscope, or heat indicator, which led in later years to the thermometer. His experiment was made by a “glass bottle about the size of a hen’s egg, the neck of which was two palms long, and as narrow as a straw. Having well heated the bulb in his hands, he placed its mouth in a vessel containing a little water, and withdrawing the heat of his hand from the bulb, instantly the water rose in the neck, more than a palm above the level of the water in the vessel.”

[p.10]During the first six years at Padua, his salary rose from about one hundred dollars to five hundred dollars, yearly. All this time, when his mind should have been free from care for his great work, he was beset with difficulties. His sister, Virginia, had married before his father’s death, but a promised dowry had never been paid, and now the brother-in-law demanded the payment. The mother, worried over the prospect, wrote to her son, Galileo, “If you carry into effect your intention of coming here next month, I shall be rejoiced, only you must not come unprovided with funds, for I see that Benedetto is determined to have his own, that is to say, what you promised him; and he threatens loudly that he will have you arrested the instant you arrive here. And as I hear you bound yourself to pay, he would have the power to arrest you, and he is just the man to do it. So I warn you, for it would grieve me much if anything of the kind were to happen.”

Livia, another sister, had become engaged to a Pisan gentleman, with the promise of a dowry of eighteen hundred ducats, eight hundred of which must be paid down. The “Pisan gentleman” could not burden himself with a wife, without funds to help support her and himself. So Galileo generously, if not wisely, borrowed six hundred ducats, and paid the necessary eight hundred, giving his sister beautiful clothes and house furnishings.

Besides these sisters, Galileo had a lazy brother to provide for, Michelangelo, a young man of some [p.11] musical talent and elegant manners, with the not unusual gift of being able to spend much and earn little. Galileo obtained a situation for him with a Polish prince, and spent two hundred crowns in getting him ready for the new position. He went thither, but soon returned, and another place had to be procured for him, at the court of the Duke of Bavaria.

While there, instead of helping to pay his sister’s dowry, as he had promised, he married; had an extravagant wedding feast, and then wrote his hard-working brother: “I know that you will say that I should have waited, and thought of our sisters before taking a wife. But, good heavens! the idea of toiling all one’s life just to put by a few farthings to give one’s sisters! This yoke would be indeed too heavy and bitter; for I am more than certain that in thirty years I should not have saved enough to cover this debt.”

With all the pressure upon him for money, Galileo kept steadily on in his absorbing studies. In the year 1609, he constructed a telescope. It is true that Hans Lipperhey, of Germany, had invented a spy-glass, and presented it to Prince Maurice, so that the principle was understood; but nobody gave it practical illustration till Galileo, having heard of the glass, began to reflect how an instrument could be made to bring distant objects near. In a leaden tube, he fixed two glasses, both having one side flat, and the other side of the one concave, and the other convex. By this, objects [p.12] appeared three times nearer and nine times larger. A few days later, he hastened with his leaden tube to Venice, to exhibit it to the Doge and the Senate. He wrote to a friend:—

“Many gentlemen and senators, even the oldest, have ascended at various times the highest bell-towers in Venice, to spy out ships at sea, making sail for the mouth of the harbor, and have seen them clearly, though without my telescope they would have been invisible for more than two hours. The effect of this instrument is to show an object at a distance of, say, fifty miles, as if it were but five miles off.

“Perceiving of what great utility such an instrument would prove in naval and military operations, and seeing that His Serenity greatly desired to possess it, I resolved four days ago to go to the palace and present it to the Doge as a free gift. And on quitting the presence-chamber, I was commanded to bide awhile in the hall of the senate, whereunto, after a little, the Illustrissimo Prioli, who is Procurator and one of the Riformatori of the University, came forth to me from the presence-chamber, and, taking me by the hand, said, ‘that the senate, knowing the manner in which I had served it for seventeen years at Padua, and being sensible of my courtesy in making it a present of my telescope, had immediately ordered the Illustrious Riformatori to elect me (with my good-will) to the professorship for life, with a stipend of one thousand florins yearly.’“

[p.13]This must have been a comfort to the now famous Galileo, as it was, doubtless, to the useless Michelangelo, and the two brothers-in-law! He could now live in comparative peace and rest.

On his return to Padua, he began eagerly to study the heavens. He found that the surface of the moon was mountainous; that the Milky Way was composed of an immense number of small stars and nebulous matter; that Orion, instead of being made up of seven heavenly bodies, had over five hundred stars; and that the Pleiades were not seven, but thirty-six. In January, 1610, he discovered the four moons of Jupiter, and that they revolved around him. July 25 of the same year, he discovered the ring of Saturn; in October, the phases of Venus, and later, the solar spots.

Florence and Padua were in a blaze of excitement. These new discoveries seemed to prove that the earth was not the centre of the universe, but that Copernicus was right when he declared the sun to be the centre. Great opposition began to develop itself. Some of the Aristotelians declared that the telescope of Galileo showed things which do not exist. “It was ridiculous,” they said, “that four planets (Jupiter’s moons) were chasing each other around a large planet.

“It is angels who make Saturn, Jupiter, the sun, etc., turn round. If the earth revolves, it must also have an angel in the centre to set it in motion; but if only devils live there, it would, [p.14] therefore, be a devil who would impart motion to the earth.

“The planets, the sun, the fixed stars, all belong to one species; namely, that of stars—they, therefore, all move, or all stand still.

“It seems, therefore, to be a grievous wrong to place the earth, which is a sink of impurity, among the heavenly bodies, which are pure and divine things.”

Galileo Galilei, Engraving, head and shoulders

Libri, one of the Pisan professors, spoke of the new discoveries as “celestial trifles.” When he died, Galileo naïvely remarked, “Libri did not choose to see my celestial trifles while he was on earth; perhaps he will, now he is gone to heaven.”

Galileo now longed for freedom from teaching, that he might have his time for study and writing. He had planned, he said, “two books on the system of the universe; an immense work (idea, concetto), full of philosophy, astronomy, and geometry: three books on local motion, a science entirely new; no one, either ancient or modern, having discovered any of the marvellous accidents which I demonstrate in natural and violent motions; so that I may, with very great reason, call it a new science, discovered by me from its very first principles: three books on mechanics, two on the demonstration of its first principles, and one of problems; and though this is a subject which has already been treated by various writers, yet all which has been written hitherto neither in quantity nor otherwise is the quarter of what I am [p.15] writing on it. I have also various treatises on natural subjects, on sound and speech, on sight and colors, on the tide, on the composition of continuous quantity, on the motion of animals, and others; besides, I have also an idea of writing some books on the military art, giving not only a model of a soldier, but teaching, with very exact rules, all which it is his duty to know that depends on mathematics; as, for instance, the knowledge of encampment, drawing up battalions, fortifications, assaults, planning, surveying, the knowledge of artillery, the use of various instruments, etc.”

With all this work in mind, he resigned the professorship at Padua, and removed to Florence, the Grand Duke Cosmo II. giving him a yearly salary of about one thousand dollars, and the title of Philosopher to His Highness.

His first thought, as ever, was for his family. He asked an advance of two years’ salary, and paid the dowry debts of his sisters’ grasping husbands.

In 1611, his expenses paid by the Grand Duke, he went to Rome to show his “celestial novelties,” as they were called, to the pope and the cardinals. He was received with great attention, and all seemed delighted to look upon the wonders of the heavens, provided always that nothing could be proved against the supposed assertion of the Bible that the earth did not move!

Galileo soon published his “Discourse on Floating [p.16] Bodies,” which aroused violent opposition; “Spots observed on the Body of the Sun,” and the “Discourse on the Tides.”

Four years later, he was again in Rome to plead for the Copernican system, and to defend his own conduct in advocating a thing in opposition to the Catholic church. He said: “I am inclined to think that the authority of Holy Scripture is intended to convince men of those truths which are necessary for their salvation, and which, being far above man’s understanding, cannot be made credible by any learning, or any other means than revelation by the Holy Spirit. But that the same God, who has endowed us with senses, reason, and understanding, does not permit us to use them, and desires to acquaint us in any other way with such knowledge as we are in a position to acquire for ourselves by means of those faculties, that, it seems to me, I am not bound to believe, especially concerning those sciences about which the Holy Scriptures contain only small fragments and varying conclusions; and this is precisely the case with astronomy, of which there is so little that the planets are not even all enumerated.”

However, in spite of Galileo’s logic, the church decreed that all books which stated the Copernican system as true should be prohibited; as a mathematical hypothesis, it might be speculated upon. This was a great disappointment to Galileo, who loved and revered the Roman Catholic faith. He went home to the Villa Segni, at Bellosguardo, [p.17] near Florence, and for seven years led a studious and secluded life.

His greatest comfort, during these quiet years, was the devotion of his daughter, Polissena, who had entered a convent as Sister Maria Celeste. While in Padua, Galileo had three children by Marina Gamba, a Venetian woman of inferior station. She afterwards married a man of her own class, and Galileo took his children to his own home; a condition of things possible with the low moral standard of the time. The two daughters were placed in a convent, while the son, Vincenzo, was educated for the profession of medicine, but he seems to have been a disappointment and a source of discomfort.

Maria Celeste, in the convent of St. Matthew, loving and tender, and helpful to all around her, wrote constantly to the man whom she idolized. “I put by carefully,” she says, “the letters you write me daily, and when not engaged with my duties, I read them over and over again. This is the greatest pleasure I have, and you may think how glad I am to read the letters you receive from persons who, besides being excellent in themselves, have you in esteem.”

Again she writes, “I leave you to imagine how pleased I am to read the letters you constantly send me. Only to see how your love for me prompts you to let me know fully what favors you receive from these gentlemen is enough to fill me with joy. Nevertheless I feel it a little hard to hear that you [p.18] intend leaving home so soon, because I shall have to do without you, and for a long time too, if I am not mistaken. And your lordship may believe that I am speaking the truth when I say that except you there is not a creature who gives me any comfort. But I will not grieve at your departure because of this, for that would be to complain when you had cause for rejoicing. Therefore I too will rejoice, and continue to pray God to give you grace and health to make a prosperous journey, so that you may return satisfied, and live long and happily, all which, I trust, will come to pass by God’s help.

“I send two baked pears for these days of vigil. But as the greatest treat of all, I send you a rose, which ought to please you extremely, seeing what a rarity it is at this season. And with the rose, you must accept its thorns, which represent the bitter passion of our Lord, while the green leaves represent the hope we may entertain that through the same Sacred Passion we, having passed through the darkness of this short winter of our mortal life, may attain to the brightness and felicity of an eternal spring in heaven.”

“Only in one respect does cloister life weigh heavily on me; that is, that it prevents my attending on you personally, which would be my desire, were it permitted. My thoughts are always with you.”

And so the seven years of study went by, with the sweet love of Maria Celeste to brighten them. [p.19] There are none so great that they can live without affection.

At the end of the seven years, Urban VIII. came to the pontifical throne, and Galileo and other scientists rejoiced, for he had seemed liberal in thought and generous in heart. When he was cardinal, he had sent a letter to Galileo, saying, “The esteem which I always entertain for yourself and your great merits has given occasion to the enclosed verses. If not worthy of you, they will serve at any rate as a proof of my affection, while I purpose to add lustre to my poetry by your renowned name. Without wasting words, then, in further apologies, which I leave to the confidence which I place in you, I beg you to receive with favor this insignificant proof of my great affection.”

At Easter, 1624, Galileo, now sixty years old, resolved to proceed to Rome, to welcome the new pope, and urge his approval of the Copernican theory. Frail in health, he was carried most of the way in a litter. During a visit of six weeks, he had six long audiences with Urban VIII.; but, though he was affably received, the pope was in no wise convinced, but rather tried to convince Galileo that he was in error.

Yet so kind was he that Galileo went back to Florence with the hope and belief that he could bring out his great work, “Dialogues on the Two Principal Systems of the World, the Ptolemaic and Copernican,” without opposition from the church. [p.20] In this book, Galileo gave the results of scientific research and discovery in the half century preceding, using such clear yet brilliant style in writing as to make the work attractive even to the unlearned.

It was ready for publication in March, 1630, but to be sure that the pope did not object, Galileo was urged to go in person to Rome. He went and presented the matter to Urban, who gave his consent provided that the title should show that the Copernican system was treated as a hypothesis merely, and that he, the pope, should write the closing argument.

Rather than forego the publication of that upon which he had worked for years, Galileo consented, and returned to Florence. A license to publish was then obtained from the Inquisitor-General, and the Vicar-General of Florence, after great delay. A second and a third time the papal authorities wished to look over the manuscript. Two years went slowly by.

Other anxieties came to the man of sixty-eight, besides the long delay. The impecunious Michelangelo sent his wife, seven children, and a German nurse, to the home of Galileo, to be taken care of. The eldest nephew was sent to Rome to study music. He was found to be obstinate, impudent, and dissolute, “wicked ways” which his weak and indulgent father said “he did not learn from me, or any one else belonging to him. It must have been the fault of his wet nurse!”

[p.21] Galileo’s son Vincenzo had married and brought his wife home to live. Strange fortune for this man of genius! Strange that he must have helpless relatives, and constant pecuniary troubles. Most great lives are as pathetic as they are great.

As ever, the one gleam of light was the daily letter from Maria Celeste, in which she expressed a tenderness beyond what any daughter ever had for a father. “But I do not know how to express myself, except by saying that I love you better than myself. For, after God, I belong to you; and your kindnesses are so numberless that I feel I could put my life in peril, were it to save you from any trouble, excepting only that I would not offend His Divine Majesty.”

Finally Galileo moved to Arcetri, over against the convent, to be near the one who alone satisfied his heart.

In January, 1632, the “Dialogues” appeared. Copies were sent to his friends and disciples throughout Italy. The whole country applauded, and at last Galileo seemed to have won the homage he had so long deserved.

But a storm was gathering. Enemies were at work prejudicing the mind of Urban VIII., making him feel that Galileo had wrought evil to the church. At once an order came from the Inquisition to secure every copy in the booksellers’ shops throughout Italy, and to forward all copies to Rome.

In October of the same year of publication, [p.22] Galileo was summoned to appear at Rome, to answer to that terror of past centuries, the charge of heresy. His friends urged that he was old and feeble, and that he would die on the journey, but Urban’s commands were peremptory.

Galileo was deeply depressed by the summons, and wrote a friend: “This vexes me so much that it makes me curse the time devoted to these studies, in which I strove and hoped to deviate somewhat from the beaten track generally pursued by learned men. I not only repent having given the world a portion of my writings, but feel inclined to suppress those still in hand, and to give them to the flames, and thus satisfy the longing desire of my enemies, to whom my ideas are so inconvenient.”

On January 20, 1633, the decrepit old man set out in a litter for Rome, arriving on February 13. On April 12, he was brought before the Inquisition, and briefly examined and then remanded to prison, though treated with great leniency. The anxiety and deprivation from outdoor exercise brought on illness, and he was confined to his bed till led a second time before the Inquisition, April 30.

Weak, aged, in fear of torture, he made the melancholy confession that his “error had been one of vainglorious ambition, and pure ignorance and inadvertence.” Pure ignorance! from the man who had studied for fifty years all that the world knew of science! But he recalled how men had died at the stake for offending the church. The [p.23] world is not full of men and women who can suffer death for their convictions, however much we may admire such courage. On May 10, he was summoned a third time before the Inquisition, and told that he had eight days in which to write his defence. In touching language he stated how the book had been examined and re examined by the authorities, so that there might be nothing heterodox in it; and then he urged them to consider his age and feeble health.

A fourth time he came before the Holy Congregation, June 21, and was asked whether he held that the sun is the centre of the solar system, and that the earth is not the centre, and that it moves. He replied, “I do not hold, and have not held this opinion of Copernicus since the command was intimated to me that I must abandon it; for the rest, I am here in your hands,—do with me what you please.”

And then June 22, in the forenoon, in the large hall of the Dominican Convent of St. Maria sopra la Minerva, in the presence of cardinals and prelates, he heard his sentence.

“The proposition that the sun is the centre of the world and does not move from its place is absurd, and false philosophically, and formally heretical, because it is expressly contrary to the Holy Scripture.

“The proposition that the earth is not the centre of the world and immovable, but that it moves, and also with a diurnal motion, is equally absurd and [p.24] false philosophically; and theologically considered, at least, erroneous in faith.... Invoking, therefore, the most holy name of our Lord Jesus Christ and of His most glorious mother and ever Virgin Mary ... we say, pronounce, sentence, declare, that you, the said Galileo, by reason of the matters adduced in process, and by you confessed as above, have rendered yourself, in the judgment of this Holy Office, vehemently suspected of heresy,—namely, of having believed and held the doctrine, which is false and contrary to the sacred and divine Scriptures,—that the sun is the centre of the world and does not move from east to west, and that the earth moves and is not the centre of the world.... We condemn you to the formal prison of this Holy Office during our pleasure, and, by way of salutary penance, we enjoin that for three years to come you repeat once a week the seven Penitential Psalms.”

Galileo was also required to “abjure, curse, and detest the aforesaid errors and heresies.” And then the white-haired man of seventy, humbly kneeling before the whole assembly, made the pitiful abjuration of his belief. “I abjure with a sincere heart and unfeigned faith, I curse and detest the said errors and heresies, and, generally, all and every error and sect contrary to the Holy Catholic Church.”

Pitiful spectacle of intolerance! If we of this nineteenth century have learned to tolerate and treat with respect the beliefs of others though [p.25] widely divergent from our own, perhaps this wretched drama was not acted in vain.

It has been said that Galileo exclaimed as he rose from his feet, “E pur si muove,” “It moves, for all that,” but this would have been well nigh an impossibility, in the midst of men who would instantly have taken him to a dungeon, and the story is no longer believed.

Photo of Monument to Galileo Galilei, inside Santa Croce church, in Florence, Italy
Monument to Galileo Galilei, inside Santa Croce church, in Florence, Italy. (source)

On July 9, poor Galileo was allowed to leave Rome for Siena, where he stayed five months in the house of the archbishop, and then became a prisoner in his own house at Arcetri, with strict injunctions that he was “not to entertain friends, nor to allow the assemblage of many at a time.”

He wrote sadly to Maria Celeste, “My name is erased from the book of the living.” Tender words came back, saying that it seemed “a thousand years” since she had seen him, and that she would recite the seven penitential psalms for him, “to save you the trouble of remembering it.”

In less than a year, sweet Maria Celeste had said the last psalms for him. She died April 1, 1634, at thirty-three years of age, leaving Galileo heart-broken; “a woman,” he said, “of exquisite mind, singular goodness, and most tenderly attached to me.”

He went to work on another book, but he said, pathetically, “I hear her constantly calling me!” Beautiful spirit, that will forever shed a halo around the name of Galileo Galilei!

In the summer of 1636, he completed his [p.26] “Dialogues on Motion,” and sent it to Leyden for publication. The next year he made his last discovery, known as the moon’s librations.

The house at Arcetri had become dark and lonely. The wife of Michelangelo, her three daughters and a son, had all died of the plague. It was doubly dark, for Galileo had become hopelessly blind, “so that this heaven, this earth, this universe, which I by my marvellous discoveries and clear demonstrations had enlarged a hundred thousand times beyond the belief of the wise men of bygone ages, henceforward for me is shrunk into such a small space as is filled by my own bodily sensations.”

His last work was a short treatise on the secondary light of the moon. “I am obliged now,” he said, sadly, “to have recourse to other hands and other pens than mine since my sad loss of sight. This, of course, occasions great loss of time, particularly now that my memory is impaired by advanced age; so that in placing my thoughts on paper, many and many a time I am forced to have the foregoing sentences read to me before I can tell what ought to follow; else I should repeat the same thing over and over.”

He had planned other work, but death came on the evening of January 8, 1642, eight years after Celeste left him. His beloved pupils, Torricelli and Viviani, and his son Vincenzo, stood by his bedside.

He desired to be buried in the family vault of [p.27] the Galilei in Santa Croce, at Florence, and the city at once voted a public funeral and three thousand crowns for a marble mausoleum. But the church at Rome prevented, lest the pernicious doctrine that the earth moves, should thereby have confirmation. He was therefore buried in an obscure corner of Del Noviziato, a side chapel of Santa Croce.

A century later, March 12, 1737, in the presence of the learned men of Italy, with great ceremony, the bones of Galileo were removed to a new resting-place in Santa Croce, and buried with his beloved friend, Viviani. An imposing monument was erected over him. The truth finally triumphed, as it always does. The works of Galileo, in sixteen volumes, are no longer prohibited, as they were in his lifetime.

Colour images from sources shown above. Note the portrait by Cresti appears to be the original from which the engraving in the book was made. From text of the first chapter of Sarah K. Bolton, Famous Men of Science (1889), 1-27. B/W engraving image precedes page 1. (source)

See also:
  • Science Quotes by Galileo Galilei.
  • 15 Feb - short biography, births, deaths and events on date of Galilei's birth.
  • Galileo Galilei - Quotations - Abjuration
  • Galileo - “And Yet It Moves” illustrated quote - Medium 500px
  • Galileo - “And Yet It Moves” illustrated quote - Large 800px
  • Galileo: A Life, by James Reston. - book suggestion.
  • Booklist for Galileo Galilei.

Nature bears long with those who wrong her. She is patient under abuse. But when abuse has gone too far, when the time of reckoning finally comes, she is equally slow to be appeased and to turn away her wrath. (1882) -- Nathaniel Egleston, who was writing then about deforestation, but speaks equally well about the danger of climate change today.
Carl Sagan Thumbnail Carl Sagan: In science it often happens that scientists say, 'You know that's a really good argument; my position is mistaken,' and then they would actually change their minds and you never hear that old view from them again. They really do it. It doesn't happen as often as it should, because scientists are human and change is sometimes painful. But it happens every day. I cannot recall the last time something like that happened in politics or religion. (1987) ...(more by Sagan)

Albert Einstein: I used to wonder how it comes about that the electron is negative. Negative-positive—these are perfectly symmetric in physics. There is no reason whatever to prefer one to the other. Then why is the electron negative? I thought about this for a long time and at last all I could think was “It won the fight!” ...(more by Einstein)

Richard Feynman: It is the facts that matter, not the proofs. Physics can progress without the proofs, but we can't go on without the facts ... if the facts are right, then the proofs are a matter of playing around with the algebra correctly. ...(more by Feynman)
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Sophie Germain
Gertrude Elion
Ernest Rutherford
James Chadwick
Marcel Proust
William Harvey
Johann Goethe
John Keynes
Carl Gauss
Paul Feyerabend
- 90 -
Antoine Lavoisier
Lise Meitner
Charles Babbage
Ibn Khaldun
Ralph Emerson
Robert Bunsen
Frederick Banting
Andre Ampere
Winston Churchill
- 80 -
John Locke
Bronislaw Malinowski
Thomas Huxley
Alessandro Volta
Erwin Schrodinger
Wilhelm Roentgen
Louis Pasteur
Bertrand Russell
Jean Lamarck
- 70 -
Samuel Morse
John Wheeler
Nicolaus Copernicus
Robert Fulton
Pierre Laplace
Humphry Davy
Thomas Edison
Lord Kelvin
Theodore Roosevelt
Carolus Linnaeus
- 60 -
Francis Galton
Linus Pauling
Immanuel Kant
Martin Fischer
Robert Boyle
Karl Popper
Paul Dirac
James Watson
William Shakespeare
- 50 -
Stephen Hawking
Niels Bohr
Nikola Tesla
Rachel Carson
Max Planck
Henry Adams
Richard Dawkins
Werner Heisenberg
Alfred Wegener
John Dalton
- 40 -
Pierre Fermat
Edward Wilson
Johannes Kepler
Gustave Eiffel
Giordano Bruno
JJ Thomson
Thomas Kuhn
Leonardo DaVinci
David Hume
- 30 -
Andreas Vesalius
Rudolf Virchow
Richard Feynman
James Hutton
Alexander Fleming
Emile Durkheim
Benjamin Franklin
Robert Oppenheimer
Robert Hooke
Charles Kettering
- 20 -
Carl Sagan
James Maxwell
Marie Curie
Rene Descartes
Francis Crick
Michael Faraday
Srinivasa Ramanujan
Francis Bacon
Galileo Galilei
- 10 -
John Watson
Rosalind Franklin
Michio Kaku
Isaac Asimov
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Sigmund Freud
Albert Einstein
Florence Nightingale
Isaac Newton

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