If you want to know the future, look at the past.

If A is a success in life, then A equals x plus y plus z. Work is x; y is play; and z is keeping your mouth shut

One is born into a herd of buffaloes and must be glad if one is not trampled under foot before one's time.

In two weeks the sheeplike masses of any country can be worked up by the newspapers into such a state of excited fury that men are prepared to put on uniforms and kill and be killed, for the sake of the sordid ends of a few interested parties. Compulsory military service seems to me the most disgraceful symptom of that deficiency in personal dignity from which civilized mankind is suffering today.

We come now to the question: what is a priori certain or necessary, respectively in geometry (doctrine of space) or its foundations? Formerly we thought everything; nowadays we think nothing. Already the distance-concept is logically arbitrary; there need be no things that correspond to it, even approximately.

Sometimes one pays most for the things one gets for nothing.

The history of scientific and technical discovery teaches us that the human race is poor in independent and creative imagination.