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

And who can doubt that it will lead to the worst disorders when minds created free by God are compelled to submit slavishly to an outside will? When we are told to deny our senses and subject them to the whim of others? When people devoid of whatsoever competence are made judgesover experts and are granted authority to treat them as they please? These are the novelties which are apt to bring about the ruin of commonwealths and the subversion of the state.

In the sciences the authority of thousands of opinions is not worth as much as one tiny spark of reason in an individual man. Besides, the modern observations deprive all former writers of any authority, since if they had seen what we see, they would have judged as we judge.

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

Count what is countable, measure what is measurable, and what is not measurable, make measurable.

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

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

See now the power of truth; the same experiment which at first glance seemed to show one thing, when more carefully examined, assures us of the contrary.

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.

And yet it does move.

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

Nature... is inexorable and immutable; she never transgresses the laws imposed upon her, nor cares a whit whether her abstruse reasons and methods of operations are understandable to men.

Where the senses fail us, reason must step in.

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

You cannot teach a man anything; you can only help him discover it in himself.

I would say here something that was heard from an ecclesiastic of the most eminent degree; "That the intention of the Holy Ghost is to teach us how one goes to heaven, not how the heaven goes."

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

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.

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

By denying scientific principles, one may maintain any paradox.

Philosophy is written in this grand book—I mean the universe—
which stands continually open to our gaze, but it cannot be understood unless one first learns to comprehend the language and interpret the characters in which it is written. It is written in the language of mathematics, and its characters are triangles, circles, and other geometrical figures, without which it is humanly impossible to understand a single word of it.

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.

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

I've loved the stars too fondly to be fearful of the night.