Galileo Galilei Quotes

A collection of quotes by Galileo Galilei.

Galileo Galilei (1564-1642) was an Italian astronomer, physicist, and mathematician. Often referred to as the "father of modern science," Galileo made groundbreaking contributions to our understanding of the physical world. He improved the telescope, enabling him to observe celestial bodies and defend the heliocentric theory proposed by Copernicus. Galileo's discoveries and experiments in mechanics laid the foundation for Newton's laws of motion. Despite clashes with the Catholic Church due to his support of Copernican heliocentrism, his work revolutionized scientific thought and forever changed our perception of the universe.

Measure what is measurable, and make measurable what is not

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

Galileo Galilei

We cannot teach people anything; we can only help them disco

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

Galileo Galilei

Nature is relentless and unchangeable, and it is indifferent

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

Galileo Galilei

By denying scientific principles, one may maintain any parad

By denying scientific principles, one may maintain any paradox.

Galileo Galilei

Science Faith Belief Reason Paradox Principles

(T)he increase of known truths stimulates the investigation,

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

Galileo Galilei

Life Art Science

It is very pious to say and prudent to affirm that the holy

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

Truth Religion Understanding

Measure what can be measured, and make measurable what canno

Measure what can be measured, and make measurable what cannot be measured.

Galileo Galilei

Spots are on the surface of the solar body where they are pr

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

Philosophy [nature] is written in that great book which ever

Philosophy [nature] is written in that great book which ever is 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. The book is written in mathematical language, and the symbols are triangles, circles and other geometrical figures, without whose help it is impossible to comprehend a single word of it; without which one wanders in vain through a dark labyrinth.

Galileo Galilei

Nature Science Astronomy Math Cosmology Geometry

The Bible shows the way to go to heaven, not the way the hea

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

Galileo Galilei

The sun, with all those planets revolving around it and depe

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

Doubt is the father of invention.

Doubt is the father of invention.

Galileo Galilei

You cannot teach a man anything; you can only help him find

You cannot teach a man anything; you can only help him find it within himself.

Galileo Galilei

If I were again beginning my studies, I would follow the adv

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

Galileo Galilei

Mathematics is the language with which God has written the u

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

Galileo Galilei

Religion Math Astronomer

But of all other stupendous inventions, what sublimity of mi

But of all other stupendous inventions, what sublimity of mind must have been his who conceived how to communicate his most secret thoughts to any other person, though very far distant either in time or place? And with no greater difficulty than the various arrangement of two dozen little signs upon paper? Let this be the seal of all the admirable inventions of man.

Galileo Galilei

I do not feel obliged to believe that the same God who has e

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

Facts which at first seem improbable will, even on scant exp

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.

Galileo Galilei

The intention of the Holy Ghost is to teach us how one goes

The intention of the Holy Ghost is to teach us how one goes to heaven, not how heaven goes.

Galileo Galilei

In questions of science, the authority of a thousand is not

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

Galileo Galilei