Explore Quotes by Galileo Galilei

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.)

Philosophy is written in that great book which ever lies before our eyes — I mean the universe — but we cannot understand it if we do not first learn the language and grasp the symbols, in which it is written.

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)

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

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

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

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

Nature is relentless and unchangeable, and it is indifferent as to whether its hidden reasons and actions are understandable to man or not.

By denying scientific principles, one may maintain any paradox.

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

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.

Facts which at first seem improbable will, even on scant explanation, drop the cloak which has hidden them and stand forth in naked and simple beauty.

I have never met a man so ignorant that I couldn't learn something from him.

Where the senses fail us, reason must step in.

Measure what is measurable, and make measurable what is not so.

And believe me, if I were again beginning my studies, I should follow the advice of Plato and start with the mathematical sciences, which proceed very cautiously and admit nothing as established until it has been rigorously demonstrated.

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.

The Bible shows the way to go to heaven, not the way the heavens go.

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

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.

Mathematics is the language with which God has written the universe.