Galileo Galilei

Where the senses fail us, reason must step in.

It is not in the power of any created being to make things true or false, but only to discover what is true or false.

To command the sun and moon, God must have given them motion.

The error of the senses is not less, but rather greater, if we try to correct them by reason without experience.

And finally, if the earth were to stop spinning, then the water in the oceans would fly off, and the mountains would crumble. So it must be moving.

Philosophy is written in this grand book, the universe, which stands continually open to our gaze. But the book 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.

It is not necessary to examine all the arguments against a position, but only the strongest.

To deny the evidence of one's own eyes, and to prefer to believe a doctrine which is contrary to all experience, shows a mind that is either very dull or very prejudiced.

The greater the number of people who believe a proposition, the more likely it is to be false.

I think that in the discussion of natural problems we ought not to begin at the authority of places of Scripture, but at sensible experiments and necessary demonstrations.

It is a beautiful and admirable thing to know how to demonstrate the truth.

The more I study nature, the more I stand amazed at the work of the Creator.

I consider the best judge to be the one who knows how to listen to both sides.

The two books from which I draw my knowledge are the book of the created world and the book of the Holy Scripture.

It is a great error to believe that the truths of faith are in any way contrary to the truths of reason.

The universe is a grand book which cannot be understood unless one first learns to comprehend the language and interpret the characters in which it is written.

The purpose of science is not to open the door to infinite wisdom, but to set a limit to infinite error.

Ignorance is the root of all evil.

It is a false and dangerous opinion that the authority of Scripture should be preferred to the authority of reason.

The deeper we penetrate into the universe, the more we realize that it is written in the language of mathematics.