Galileo Galilei

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

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.

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.

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

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

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

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

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

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.

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

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

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.

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

Where the senses fail us reason must step in.

By denying scientific principles one may maintain any paradox.

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

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

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