What we need is imagination, but imagination in a terrible strait-jacket.

There are all kinds of interesting questions that come from a knowledge of science, which only adds to the excitement and mystery and awe of a flower.

One cannot understand... the universality of laws of nature, the relationship of things, without an understanding of mathematics. There is no other way to do it.

The unanswerable mysteries... the attitude that all is uncertain... to summarize it - the humility of the intellect.

I don't know what's the matter with people: they don't learn by understanding, they learn by some other way — by rote or something. Their knowledge is so fragile!

We scientists are clever — too clever — are you not satisfied? Is four square miles in one bomb not enough? Men are still thinking. Just tell us how big you want it!

If you have any talent, or any occupation that delights you, do it, and do it to the hilt. Don't ask why, or what difficulties you may get into.