The world is not threatened by evil people, but by those who allow evil to take place.

It is really a puzzle what drives one to take one's work so devilishly seriously.

On the other hand, the concept owes its meaning and its justification exclusively to the totality of the sense impressions which we associate with it.

I cannot conceive of a God who rewards and punishes his creatures, or has a will of the kind that we experience in ourselves. Neither can I nor would I want to conceive of an individual that survives his physical death; let feeble souls, from fear or absurd egoism, cherish such thoughts. I am satisfied with the mystery of the eternity of life and with the awareness and a glimpse of the marvelous structure of the existing world, together with the devoted striving to comprehend a portion, be it ever so tiny, of the Reason that manifests itself in nature.

Imagination without knowledge may create beautiful things, knowledge without imagination can create only perfect ones.

Dear Posterity, If you have not become more just, more peaceful, and in general more sensible... then may the Devil take you!

You believe in a God who plays dice, I in complete law and order.