Galilei Galileo Quotes & Sayings

All truths are easy to understand once they are discovered; the point is to discover them. — Galileo Galilei

Innovations, free thinking is blowing like a storm; those that stand in front of it, ignorant scholars like you, false scientists, perverse conservatives, obstinate goats, resisting mules are being crushed under the weight of these innovations. You are nothing but ants standing in front of the giants; nothing but chicks trying to challenge roaring volcanoes! — Mehmet Murat Ildan

Nothing can be taught to a man, only it's possibly to help him to discover it inside. — Galileo Galilei

In regard to the philosophers, if they be true philosophers, i.e., lovers of truth, they should not be irritated that the earth moves. Rather, if they realize that they have held a false belief, they should thank those have shown them the truth; and if their opinion stands firm that the earth doesn't move, they will have reason to boast than be angered. — Galileo Galilei

Scripture is a book about going to Heaven. It's not a book about how the heavens go. — Galileo Galilei

The sun, with all those planets revolving around it and dependent on it, can still ripen a bunch of grapes as if it had nothing else in the universe to do. — Galileo Galilei

To me, a great ineptitude exists on the part of those who would have it that God made the universe more in proportion to the small capacity of their reason than to His immense, His infinite, power. — Galileo Galilei

Holy Scripture could never lie or err ... its decrees are of absolute and inviolable truth. — Galileo Galilei

The Divine intellect indeed knows infinitely more propositions [than we can ever know]. But with regard to those few which the human intellect does understand, I believe that its knowledge equals the Divine in objective certainty. — Galileo Galilei

If I were again beginning my studies, I would follow the advice of Plato and start with mathematics. — Galileo Galilei

It is a beautiful and delightful sight to behold the body of the Moon. — Galileo Galilei

In the sciences, the authority of thousands of opinions is not worth as much as one tiny spark of reason in an individual man. — Galileo Galilei

Their vain presumption of knowing all can take beginning solely from their never having known anything; for if one has but once experienced the perfect knowledge of one thing, and truly tasted what it is to know, he shall perceive that of infinite other conclusions he understands not so much as one. — Galileo Galilei

Nature's great book is written in mathematics. — Galileo Galilei

I know it too well, my friend. Fresh water does not come out of a bitter spring; you don't expect to get rose perfume coming out of a rubbish heap, neither scorpions to kiss people! — Mehmet Murat Ildan

To go to the wine house and not to get drunk is as difficult as to dive into a pool and not get wet! — Mehmet Murat Ildan

They know that it is human nature to take up causes whereby a man may oppress his neighbor, no matter how unjustly ... Hence they have had no trouble in finding men who would preach the damnability and heresy of the new doctrine from the very pulpit ... — Galileo Galilei

It vexes me when they would constrain science by the authority of the Scriptures, and yet do not consider themselves bound to answer reason and experiment. — Galileo Galilei

I do not feel obliged to believe that the same God who has endowed us with sense, reason, and intellect has intended us to forgo their use. — Galileo Galilei

After a duration of a thousand years, the power of astrology broke down when, with Copernicus, Kepler, and Galileo, the progress of astronomy overthrew the false hypothesis upon which the entire structure rested, namely the geocentric system of the universe. The fact that the earth revolves in space intervened to upset the complicated play of planetary influences, and the silent stars, related to the unfathomable depths of the sky, no longer made their prophetic voices audible to mankind. Celestial mechanics and spectrum analysis finally robbed them of their mysterious prestige. — Franz Cumont

You cannot teach a person something he does not already know, you can only bring what he does know to his awareness. — Galileo Galilei

In the long run my observations have convinced me that some men, reasoning preposterously, first establish some conclusion in their minds which, either because of its being their own or because of their having received it from some person who has their entire confidence, impresses them so deeply that one finds it impossible ever to get it out of their heads. — Galileo Galilei

With regard to matters requiring thought: the less people know and understand about them, the more positively they attempt to argue concerning them. — Galileo Galilei

Long experience has taught me this about the status of mankind with regard to matters requiring thought: the less people know and understand about them, the more positively they attempt to argue concerning them, while on the other hand to know and understand a multitude of things renders men cautious in passing judgment upon anything new. — Galileo Galilei

Measure what is measurable, and make measurable what is not so. — Galileo Galilei

Passion is the genesis of genius. — Galileo Galilei

The hypothesis is pretty; its only fault is that it is neither demonstrated nor demonstrable. Who does not see that this is purely arbitrary fiction that puts nothingness as existing and proposes nothing more than simple noncontradiciton? — Galileo Galilei

The deeper I go in considering the vanities of popular reasoning, the lighter and more foolish I find them. What greater stupidity can be imagined than that of calling jewels, silver, and gold "precious," and earth and soil "base"? — Galileo Galilei

Philosophy itself cannot but benefit from our disputes, for if our conceptions prove true, new achievements will be made; if false, their refutation will further confirm the original doctrines. — Galileo Galilei

I do not think it is necessary to believe that the same God who has given us our senses, reason, and intelligence wished us to abandon their use, giving us by some other means the information that we could gain through them. — Galileo Galilei

I would beg the wise and learned fathers (of the church) to consider with all diligence the difference which exists between matters of mere opinion and matters of demonstration ... [I]t is not in the power of professors of the demonstrative sciences to alter their opinions at will, so as to be now of one way of thinking and now of another ... [D]emonstrated conclusions about things in nature of the heavens, do not admit of being altered with the same ease as opinions to what is permissible or not, under a contract, mortgage, or bill of exchange. — Galileo Galilei

It's very dangerous to invent something in our times; ostentatious men of the other world, who are hostile to innovations, roam about angrily. To live in peace, one has to stay away from innovations and new ideas. Innovations, like trees, attract the most destructive lightnings to themselves. — Mehmet Murat Ildan

We see only the simple motion of descent, since that other circular one common to the Earth, the tower, and ourselves remains imperceptible. There remains perceptible to us only that of the stone, which is not shared by us; and, because of this, sense shows it as by a straight line, always parallel to the tower, which is built upright and perpendicular upon the terrestrial surface. — Galileo Galilei

The greatest wisdom is to get to know oneself. — Galileo Galilei

If there were as great a scarcity of soil as of jewels or precious metals, there would not be a prince who would not spend a bushel of diamonds and rubies and a cartload of gold just to have enough earth to plant a jasmine in a little pot, or to sow an orange seed and watch it sprout, grow, and produce its handsome leaves, its fragrant flowers, and fine fruit. — Galileo Galilei

In the future, there will be opened a gateway and a road to a large and excellent science into which minds more piercing than mine shall penetrate to recesses still deeper. — Galileo Galilei

A fortune-teller means a braggart anyway. Don't you know that a donkey can't do but braying, a wolf can't do but howling, a horse can't do but neighing, and a fortune-teller can't do but telling lies? — Mehmet Murat Ildan

Infinities and indivisibles transcend our finite understanding, the former on account of their magnitude, the latter because of their smallness; Imagine what they are when combined. — Galileo Galilei

I cannot but be astonished that Sarsi should persist in trying to prove by means of witnesses something that I may see for myself at any time by means of experiment. Witnesses are examined in doutbful matters which are past and transient, not in those which are actual and present. A judge must seek by means of witnesses to determine whether Peter injured John last night, but not whether John was injured, since the judge can see that for himself. — Galileo Galilei

The Grand Duke [of Tuscany] ... after observing the Medicaean plants several times with me ... has now invited me to attach myself to him with the annual salary of one thousand florins, and with the title of Philosopher and Principal Mathematicial to His Highness; without the duties of office to perform, but with the most complete leisure; so that I can complete my Treatises ... — Galileo Galilei

To our natural and human reason, I say that these terms 'large,' 'small,' 'immense,' 'minute,' etc. are not absolute but relative; the same thing in comparison with various others may be called at one time 'immense' and at another 'imperceptible. — Galileo Galilei

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. — Galileo Galilei

I wish, my dear Kepler, that we could have a good laugh together at the extraordinary stupidity of the mob. What do you think of the foremost philosophers of this University? In spite of my oft-repeated efforts and invitations, they have refused, with the obstinacy of a glutted adder, to look at the planets or the Moon or my glass [telescope]. — Galileo Galilei

Surely, God could have caused birds to fly with their bones made of solid gold, with their veins full of quicksilver, with their flesh heavier than lead, and with their wings exceedingly small. He did not, and that ought to show something. It is only in order to shield your ignorance that you put the Lord at every turn to the refuge of a miracle. — Galileo Galilei

Names and attributes must be accommodated to the essence of things, and not the essence to the names, since things come first and names afterwards. — Galileo Galilei

Well, since paradoxes are at hand, let us see how it might be demonstrated that in a finite continuous extension it is not impossible for infinitely many voids to be found. — Galileo Galilei

It reveals to me the causes of many natural phenomena that are entirely incomprehensible in the light of the generally accepted hypotheses. To refute the latter I collected many proofs, but I do not publish them ... I would dare to publish my speculations if there were people men like you. — Galileo Galilei

I am not very impressed with theological arguments whatever they may be used to support. Such arguments have often been found unsatisfactory in the past. In the time of Galileo it was argued that the texts, 'And the sun stood still ... and hasted not to go down about a whole day' (Joshua x. 13) and 'He laid the foundations of the earth, that it should not move at any time' (Psalm cv. 5) were an adequate refutation of the Copernican theory. — Alan Turing

Philosophy is written in this grand book, the universe, which stands continually open to our gaze. But the book cannot be understood unless one first learns to comprehend the language and read the characters in which it is written. It is written in the language of mathematics, and its characters are triangles, circles, and other geometric figures without which it is humanly impossible to understand a single word of it; without these one is wandering in a dark labyrinth. - Galileo Galilei, The Assayer, 1623 — Max Tegmark

That sculpture is more admirable than painting for the reason that it contains relief and painting does not is completely false ... Rather, how much more admirable the painting must be considered, if having no relief at all, it appears to have as much as sculpture! — Galileo Galilei

I never worry about how many legs my chicken has, about whether it can fly or not, about which cock was her husband; that my hen gives me eggs is enough for me! — Mehmet Murat Ildan

I have been judged vehemently suspect of heresy, that is, of having held and believed that the sun in the centre of the universe and immoveable, and that the earth is not at the center of same, and that it does move. Wishing however, to remove from the minds of your Eminences and all faithful Christians this vehement suspicion reasonably conceived against me, I abjure with a sincere heart and unfeigned faith, I curse and detest the said errors and heresies, and generally all and every error, heresy, and sect contrary to the Holy Catholic Church. (Quoted in Shea and Artigas 194) — Galileo Galilei

The earth, in fair and grateful exchange, pays back to the moon an illumination similar to that which it receives from her throughout nearly all the darkest gloom of the night. — Galileo Galilei

It is very pious to say and prudent to affirm that the holy Bible can never speak untruth
whenever its true meaning is understood. But I believe nobody will deny that it is often very abstruse, and may say things which are quite different from wha. — Galileo Galilei

The doctrine that the earth is neither the center of the universe nor immovable, but moves even with a daily rotation, is absurd, and both philosophically and theologically false, and at the least an error of faith. — Galileo Galilei

We come astonishingly close to the mystical beliefs of Pythagoras and his followers who attempted to submit all of life to the sovereignty of numbers. Many of our psychologists, sociologists, economists and other latter-day cabalists will have numbers to tell them the truth or they will have nothing ... We must remember that Galileo merely said that the language of nature is written in mathematics. He did not say that everything is. And even the truth about nature need not be expressed in mathematics. For most of human history, the language of nature has been the language of myth and ritual. These forms, one might add, had the virtues of leaving nature unthreatened and of encouraging the belief that human beings are part of it. It hardly befits a people who stand ready to blow up the planet to praise themselves too vigorously for having found the true way to talk about nature. — Neil Postman

Measure what can be measured, and make measurable what cannot be measured. — Galileo Galilei

Take note, theologians, that in your desire to make matters of faith out of propositions relating to the fixity of sun and earth you run the risk of eventually having to condemn as heretics those who would declare the earth to stand still and the sun to change position-eventually, I say, at such a time as it might be physically or logically proved that the earth moves and the sun stands still. — Galileo Galilei

I truly believe the book of philosophy to be that which stands perpetually open before our eyes, though since it is written in characters different from those of our alphabet it cannot be read by everyone. — Galileo Galilei

Man is a 'jar of mistakes', dear Giulia; as we have made a mistake, we are human; this proves it! — Mehmet Murat Ildan

I have been in my bed for five weeks, oppressed with weakness and other infirmities from which my age, seventy four years, permits me not to hope release. Added to this (proh dolor! [O misery!]) the sight of my right eye - that eye whose labors (dare I say it) have had such glorious results - is for ever lost. That of the left, which was and is imperfect, is rendered null by continual weeping. — Galileo Galilei

Being infinitely amazed, so do I give thanks to God, Who has been pleased to make me the first observer of marvelous things, unrevealed to bygone ages. — Galileo Galilei

In time you may discover everything that can be discovered, and still your progress will only be progress away from humanity. The distance between you and them can one day become so great that your joyous cry over some new gain could be answered by an universal shriek of horror. — Galileo Galilei

You cannot teach a man anything, you can only help him find it within himself. — Galileo Galilei

I think that in the discussion of natural problems we ought to begin not with the Scriptures, but with experiments, and demonstrations. — Galileo Galilei

One can truly say that the irresistible progress of natural science since the time of Galileo has made its first halt before the study of the higher parts of the brain, the organ of the most complicated relations of the animal to the external world. And it seems, and not without reason, that now is the really critical moment for natural science; for the brain, in its highest complexity - the human brain - which created and creates natural science, itself becomes the object of this science. — Ivan Pavlov

I learned an important lesson: Never take the obvious for granted. Once upon a time, it was so obvious that a four-pound rock would plummet earthward twice as fast as a two-pound rock that no one ever bothered to test it. That is, until Galileo Galilei came along and took ten minutes to perform an elegantly simple experiment that yielded a counterintuitive result and changed the course of history. — V.S. Ramachandran

Mathematics is the language with which God has written the universe. — Galileo Galilei

in the ballroom of the Metropol Hotel on the twenty-first of June 1926, was the heretic, Galileo of Galilei, vindicated by a ping, a splat, a smash, a thunk, a thump, and a thud. Of — Amor Towles

It has always seemed to me extreme presumptuousness on the part of those who want to make human ability the measure of what nature can and knows how to do, since, when one comes down to it, there is not one effect in nature, no matter how small, that even the most speculative minds can fully understand. — Galileo Galilei

But why has our physical world revealed such extreme mathematical regularity that astronomy superhero Galileo Galilei proclaimed nature to be "a book written in the language of mathematics," and Nobel Laureate Eugene Wigner stressed the "unreasonable effectiveness of mathematics in the physical sciences" as a mystery demanding an explanation? — Max Tegmark

Among the great men who have philosophized about [the action of the tides], the one who surprised me most is Kepler. He was a person of independent genius, [but he] became interested in the action of the moon on the water, and in other occult phenomena, and similar childishness. — Galileo Galilei

The vain presumption of understanding everything can have no other basis than never having understood anything. For anyone who had ever experienced just once the perfect understanding of one single thing, and had truly tasted how knowledge is accomplished, would recognize that of the infinity of other truths he understands nothing. — Galileo Galilei

Where the senses fail us, reason must step in. — Galileo Galilei

The first man to understand the extraordinary magical power of applying mathematical calculation to things in nature was an Italian called Galileo Galilei. — E.H. Gombrich

Knowing thyself, that is the greatest wisdom. — Galileo Galilei

God is known by nature in his works, and by doctrine in his revealed word. — Galileo Galilei

It is surely harmful to souls to make it a heresy to believe what is proved. — Galileo Galilei

I am certainly interested in a tribunal in which, for having used my reason, I was deemed little less than a heretic. Who knows but men will reduce me from the profession of a philosopher to that of historian of the Inquisition! — Galileo Galilei

Oh, my dear Kepler, how I wish that we could have one hearty laugh together. Here, at Padua, is the principal professor of philosophy, whom I have repeatedly and urgently requested to look at the moon and planets through my glass, [telescope] which he pertinaciously refuses to do. Why are you not here? what shouts of laughter we should have at this glorious folly! and to hear the professor of philosophy at Pisa laboring before the grand duke with logical arguments, as if with magical incantations, to charm the new planets out of the sky. — Galileo Galilei

When the moon is ninety degrees away from the sun it sees but half the earth illuminated (the western half). For the other (the eastern half) is enveloped in night. Hence the moon itself is illuminated less brightly from the earth, and as a result its secondary light appears fainter to us. — Galileo Galilei

We must say that there are as many squares as there are numbers. — Galileo Galilei

I esteem myself happy to have as great an ally as you in my search for truth. I will read your work ... all the more willingly because I have for many years been a partisan of the Copernican view because it reveals to me the causes of many natural phenomena that are entirely incomprehensible in the light of the generally accepted hypothesis. To refute the latter I have collected many proofs, but I do not publish them, because I am deterred by the fate of our teacher Copernicus who, although he had won immortal fame with a few, was ridiculed and condemned by countless people (for very great is the number of the stupid).

{Letter to fellow revolutionary astronomer Johannes Kepelr} — Galileo Galilei

Nature is written in mathematical language. — Galileo Galilei

The book of nature is written in the language of mathematics. — Galileo Galilei

In this book, you will encounter various interesting geometries that have been thought to hold the keys to the universe. Galileo Galilei (1564-1642) suggested that "Nature's great book is written in mathematical symbols." Johannes Kepler (1571-1630) modeled the solar system with Platonic solids such as the dodecahedron. In the 1960s, physicist Eugene Wigner (1902-1995) was impressed with the "unreasonable effectiveness of mathematics in the natural sciences." Large Lie groups, like E8-which is discussed in the entry "The Quest for Lie Group E8 (2007)"- may someday help us create a unified theory of physics. in 2007, Swedish American cosmologist Max Tegmark published both scientific and popular articles on the mathematical universe hypothesis, which states that our physical reality is a mathematical structure-in other words, our universe in not just described by mathematics-it is mathematics. — Clifford A. Pickover

The Milky Way is nothing else but a mass of innumerable stars planted together in clusters. — Galileo Galilei

They seemed to forget that the increase of known truths stimulates the investigation, establishment and growth of the arts; not their dimination or destruction. — Galileo Galilei

I, Galileo, son of the late Vicenzo Galilei, swear that I never said that the prime numbers are useless. What I said was that you cannot count lunar craters by counting 2, 3, 5, 7 ... — Galileo Galilei

The mind God is looking for in man is a doubting, questioning mind, not a dogmatic mind; dogmatic reasoning is wrong reasoning. Dogmatic reason ties a huge rock to a man's foot and stops him forever from advancing. — Mehmet Murat Ildan

We are surrounded by the dry thorns of the Inquisition on all four sides; throwing around words burning like fire is the shortest way to one's grave! — Mehmet Murat Ildan

You can't teach anybody anything, only make them realize the answers are already inside them. — Galileo Galilei

Spots are on the surface of the solar body where they are produced and also dissolved, some in shorter and others in longer periods. They are carried around the Sun; an important occurrence in itself. — Galileo Galilei

In questions of science, the authority of a thousand is not worth the humble reasoning of a single individual. — Galileo Galilei

But, because my private lectures and domestic pupils are a great hinderance and intteruption of my studies, I wish to live entirely exempt from the former, and in great measure from the latter ... in short, I should wish to gain my bread from my writings. — Galileo Galilei

You may force me to say what you wish; you may revile me for saying what I do. But it moves. — Galileo Galilei

What has philosophy got to do with measuring anything? It's the mathematicians you have to trust, and they measure the skies like we measure a field. — Galileo Galilei

It helps nothing to cry and complain, to pluck our hair. There's no difference between getting mad at our fate and getting mad at rocks and stones. The ears of Fate are completely deaf; anyway, it doesn't matter whether she hears our voices or not; when the moment comes, she only speaks of the things she has already designed and rains the orders she has already planned. — Mehmet Murat Ildan

My dear Kepler, what would you say of the learned here, who, replete with the pertinacity of the asp, have steadfastly refused to cast a glance through the telescope? What shall we make of this? Shall we laugh, or shall we cry? — Galileo Galilei

I would say here something that was heard from an ecclesiastic of the most eminent degree: The intention of the Holy Spirit is to teach us how one goes to heaven, not how the heavens go. — Galileo Galilei