“There's a lot of difference between listening and hearing.”

“There is a great deal of difference between an eager man who wants to read a book and a tired man who wants a book to read.”

“Perhaps we are both doing what we think right. But what we think right is so damned different that there can be nothing between us in the way of concession. There is nothing possible between us but honor and death.”

“The difference between the poet and the mathematician is that the poet tries to get his head into the heavens while the mathematician tries to get the heavens into his head.”

“I do not admit that theological points are small points. Theology is only thought applied to religion; and those who prefer a thoughtless religion need not be so very disdainful of others with a more rationalistic taste. The old joke that the Greek sects only differed about a single letter is about the lamest and most illogical joke in the world. An atheist and a theist only differ by a single letter; yet theologians are so subtle as to distinguish definitely between the two.”

“If the devil tells you something is too fearful to look at, look at it. If he says something is too terrible to hear, hear it. If you think some truth unbearable, bear it.”

“My brain and this world don't fit each other; and there's an end of it.”