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

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

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

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.

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

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

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

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

By denying scientific principles, one may maintain any paradox.

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 moves.

Where the senses fail us, reason must step in.

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

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

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

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.

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