Two truths cannot contradict one another.

I wish, my dear Kepler, that we could have a good laugh together at the extraordinary stupidity of the mob. What do you think of the foremost philosophers of this University? In spite of my oft-repeated efforts and invitations, they have refused, with the obstinacy of a glutted adder, to look at the planets or the Moon or my glass [telescope].

Some, merely to contradict what I had said, did not scruple to cast doubt upon things they had seen with their own eyes again and again.

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

To understand the Universe, you must understand the language in which it's written, the language of Mathematics.

Scripture is a book about going to Heaven. It's not a book about how the heavens go.

God is known by nature in his works, and by doctrine in his revealed word.