I do not feel obliged to believe that the same God who has endowed us with senses, reason, and intellect has intended us to forego their use.

The Universe is a grand book which cannot be read until one first learns to comprehend the language and become familiar with the characters in which it is composed. It is written in the language of mathematics.

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.

To command their professors of astronomy to refute their own observations is to command them not to see what they do see and not to understand what they do understand.

Being infinitely amazed, so do I give thanks to God, Who has been pleased to make me the first observer of marvelous things, unrevealed to bygone ages.

The surface of the Moon is not smooth, uniform, and precisely spherical as a great number of philosophers believe it to be, but is uneven, rough, and full of cavities and prominences, being not unlike the face of the Earth, relieved by chains of mountains and deep valleys.

You cannot teach a person something he does not already know, you can only bring what he does know to his awareness.