Playfullness is the essential feature of productive thought.

If everybody lived as I do, surely the writing of romance novels would never have come into being.

A man has to work so hard so that something of his personality stays alive. A tomcat has it so easy, he has only to spray and his presence is there for years on rainy days.

Paper is to write things down that we need to remember. Our brains are used to think.

It stands to the everlasting credit of science that by acting on the human mind it has overcome man's insecurity before himself and before nature.

I have never obtained any ethical values from my scientific work.

Just as with the man in the fairy tale who turned whatever he touched into gold, with me everything is turned into newspaper clamor.