To know that we know what we know and that we do not know what we do not know that is true knowledge.

The bluebird carries the sky on his back.

What is most of our boasted so-called knowledge but a conceit that we know something, which robs us of the advantage of our actual ignorance?

I have no doubt that it is a part of the destiny of the human race, in its gradual improvement, to leave off eating animals, as surely as savage tribes have left off eating each other when they came in contact with the more civilized.

What sort of philosophers are we, who know absolutely nothing of the origin and destiny of cats?

City life - millions of people being lonesome together.