Galileo Galilei Quotes

Nature is written in mathematical language.

Nature's great book is written in mathematics.

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.

E pur si muove. "Albeit It does move". (That's what Galileo purportedly muttered after torturers forced him to recant his theory that the earth orbits the sun.)

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.

They who depend upon manifest observations will philosophize better than those who persist in opinions repugnant to the senses.

To command their professors of astronomy to refute their own observations is to command them not to see what they do see and not to understand what they do understand.

I do not know what to say in a case so surprising, so unlooked for and so novel.

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 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.

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.

We must say that there are as many squares as there are numbers.

Holy Writ was intended to teach men how to go to Heaven not how the heavens go.

Some, merely to contradict what I had said, did not scruple to cast doubt upon things they had seen with their own eyes again and again.

[Copernicus] did not ignore the Bible, but he knew very well that if his doctrine were proved, then it could not contradict the Scriptures when they were rightly understood.

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.

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.

For my part I consider the earth very noble and admirable precisely because of the diverse alterations, changes, generations, etc. that occur in it incessantly.

One can understand nature only when one has learned the language and the signs in which it speaks to us; but this language is mathematics and these signs are methematical figures.

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.

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

It was granted to me alone to discover all the new phenomena in the sky and nothing to anybody else. This is the truth which neither envy nor malice can supress.

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

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

The sun, with all the planets revolving around it, and depending on it, can still ripen a bunch of grapes as though it had nothing else in the universe to do.

A stone thrown up into the air is bound to fall down, and absolute power is like a huge stone thrown up into the air.

Minds with fixed ideas are like granite: They can never be penetrated with soft words and gentle persuasions.

(T)he increase of known truths stimulates the investigation, establishment, and growth of the arts.

And, believe me, if I were again beginning my studies, I should follow the advice of Plato and start with mathematics.

We cannot teach people anything we can only help them discover it within themselves.

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.

The nature of the human mind is such that unless it is stimulated by images of things acting upon it from without, all remembrance of them passes easily away.

He who looks the higher is the more highly distinguished, and turning over the great book of nature (which is the proper object of philosophy) is the way to elevate one's gaze.

All truths are easy to understand once they are discovered the point is to discover them.

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