[About describing atomic models in the language of classical physics:]We must be clear that when it comes to atoms, language can be used only as in poetry. The poet, too, is not nearly so concerned with describing facts as with creating images and establishing mental connections.

— Niels Bohr

An expert is a man who has made all the mistakes which can be made in a very narrow field.

— Niels Bohr

An expert is a person who has made all the mistakes that can be made in a very narrow field.

— Niels Bohr

Einstein, stop telling God what to do!

— Niels Bohr

Every great and deep difficulty bears in itself its own solution. It forces us to change our thinking in order to find it.

— Niels Bohr

Every sentence I utter must be understood not as an affirmation but as a question.[A caution he gives his students, to be wary of dogmatism.]

— Niels Bohr

Everything we call real is made of things that cannot be regarded as real.

— Niels Bohr

How wonderful that we have met with a paradox. Now we have some hope of making progress.

— Niels Bohr

I myself find the division of the world into an objective and a subjective side much too arbitrary. The fact that religions through the ages have spoken in images, parables, and paradoxes means simply that there are no other ways of grasping the reality to which they refer. But that does not mean that it is not a genuine reality. And splitting this reality into an objective and a. subjective side won't get us very far.

— Niels Bohr

It is not enough to be wrong, one must also be polite.

— Niels Bohr