The theologians also should not be irritated. For if they find that this opinion is false, then they would be free to condemn it; and if they discover that it is true, they ought to thank those who have opened the way to finding the true sense of the Scriptures and who have prevented them from falling into the grave scandal of condemning a true proposition.

It reveals to me the causes of many natural phenomena that are entirely incomprehensible in the light of the generally accepted hypotheses. To refute the latter I collected many proofs, but I do not publish them ... I would dare to publish my speculations if there were people men like you.

But let us remember that we are dealing with infinities and indivisibles both of which transcend our finite understanding, the former on account of their magnitude, the latter because of their smallness.

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

Holy Writ was intended to teach men how to go to Heaven not how the heavens go.

Knowing thyself, that is the greatest wisdom.

I, Galileo, son of the late Vicenzo Galilei, swear that I never said that the prime numbers are useless. What I said was that you cannot count lunar craters by counting 2, 3, 5, 7.