"If you wish at once to do nothing and be respectable nowadays, the best pretext is to be at work on some profound study."

"The truth cannot be asserted without denouncing the falsehood."

"Chance is a name for our ignorance."

"If atheism is to be used to express the state of mind in which God is identified with the unknowable, and theology is pronounced to be a collection of meaningless words about unintelligible chimeras, then I have no doubt, and I think few people doubt."

"Walking is the natural recreation for a man who desires not absolutely to suppress his intellect but to turn it out to play for a season. All great men of letters have therefore been enthusiastic walkers."

"Every man who says frankly and fully what he thinks is doing a public service."