Many a young lady does not realize just how strong her love for a young man is until he fails to pass the approval test with her parents. There is no fear in love; but perfect love casteth out fear. Of all forms of caution, caution in love is the most fatal. There are only two truly infinite things, the universe and stupidity. And I am unsure about the universe.

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.

Conscious man, to be sure, has at all times been keenly aware that life is an adventure, that life must, forever, be wrested from death.

An oligarchy of private capital cannot be effectively checked even by a democratically organized political society because under existing conditions, private capitalists inevitably control, directly or indirectly, the main sources of information.

What can the schools do to defend democracy? Should they preach a specific political doctrine? I believe they should not. If they are able to teach young people to have a critical mind and a socially oriented attitude, they will have done all that is necessary.

There exists a passion for comprehension, just as there exists a passion for music. That passion is rather common in children, but gets lost in most people later on. Without this passion there would be neither mathematics nor natural science.

Solutions to tough problems should be made as simple as possible - and no simpler.