I soon learned to scent out that which was able to lead to fundamentals and to turn aside from everything else, from the multitude of things which clutter up the mind and divert it from the essential.

If you're not sure why you're doing something, you can never do enough of it. Imagination is more important than knowledge.

Falling in love is not at all the most stupid thing that people do - but gravitation cannot be held responsible for it.

We are here for the sake of others

I see in Nature a magnificent structure... that must fill a thinking person with a feeling of humility.

Marvellous, what ideas the young people have these days. But I don't believe a word of it.

You do not really understand something unless you can explain it to your grandmother.