There is, fortunately, a minority composed of those who recognize early in their lives that the most beautiful and satisfying experiences open to humankind are not derived from the outside, but are bound up with the development of the individual's own feeling, thinking and acting. The genuine artists, investigators and thinkers have always been persons of this kind. However inconspicuously the life of these individuals runs its course, none the less the fruits of their endeavors are the most valuable contributions which one generation can make to its successors.

The formulation of the problem is often more essential than its solution, which may be merely a matter of mathematical or experimental skill.

The one who walks alone, is likely to find himself in places no one has ever been.

I am by heritage a Jew, by citizenship a Swiss, and by makeup a human being, and only a human being, without any special attachment to any state or national entity whatsoever.

If there is no price to be paid, it is also not of value.

Science can only ascertain what is, but not what should be, and outside of its domain value judgements of all kinds remain necessary.

There is no vaccine against stupidity.