One can state, without exaggeration, that the observation of and the search for similarities and differences are the basis of all human knowledge.

I have not the slightest pretension to call my verses poetry; I write now and then for no other purpose than to relieve depression or to improve my English.

I intend to leave after my death a large fund for the promotion of the peace idea, but I am skeptical as to its results.

Justice is to be found only in the imagination.

My dynamite will sooner lead to peace than a thousand world conventions. As soon as men will find that in one instant, whole armies can be utterly destroyed, they surely will abide by golden peace.

Contentment is the only real wealth.

Lying is the greatest of all sins.