When you are courting a nice girl an hour seems like a second. When you sit on a red-hot cinder a second seems like an hour. That's relativity.

When you trip over love, it is easy to get up. But when you fall in love, it is impossible to stand again.

The ordinary adult never gives a thought to space-time problems ... I, on the contrary, developed so slowly that I did not begin to wonder about space and time until I was an adult. I then delved more deeply into the problem than any other adult or child would have done.

The only justifiable purpose of political institutions is to ensure the unhindered development of the individual.

Imagination is more important than knowledge. Knowledge is limited. Imagination encircles the world.

If one asks the whence derives the authority of fundamental ends, since they cannot be stated and justified merely by reason, one can only answer: they exist in a healthy society as powerful traditions, which act upon the conduct and aspirations and judgments of the individuals; they are there, that is, as something living, without its being necessary to find justification for their existence.

Regarding sex education: no secrets!