Galileo Galilei

The deeper I go in considering the vanities of popular reasoning, the lighter and more foolish I find them.

It is a most beautiful and delightful sight to behold the body of the Moon, which is distant from us nearly sixty semi-diameters of the Earth.

The constant activity which you Venetians display in your famous arsenal suggests to the studious mind a large field for investigation.

I believe that a more natural and harmonious effect is produced by the true theory than by the false one.

The testimony of the senses must be subordinated to the reasoning faculty.

Scripture is a book about how to go to heaven, not how the heavens go.

The laws of Nature are written by the hand of God in the language of mathematics.

I am certainly interested in a tribunal in which, for having used my reason, I was deemed little less than a heretic.

The surface of the Moon is not smooth, uniform, and precisely spherical as a great number of philosophers believe it and the other heavenly bodies to be.

What a business it is to have to prove to people that the Earth is round!

If reasoning were like hauling I should agree that several reasoners would be worth more than one, just as several horses can haul more sacks of grain than one. But reasoning is like racing and not like hauling, and a single Arabian steed can outrun a hundred plowhorses.

The authority of the Bible is intended to persuade men of those truths which are necessary for their salvation. But it is not intended to teach us the sciences.

The discoveries we make with the telescope are by no means agreeable to the Peripatetic philosophy.

I discovered in the heavens many things that had not been seen before our own age.

To command the professors of astronomy to confute their own observations is to enjoin an impossibility, for it is to command them not to see what they do see, and not to understand what they do understand.

I have been condemned on account of my unwillingness to profess a belief which I do not possess.