The opposite of a fact is falsehood, but the opposite of one profound truth may very well be another profound truth. — Niels Bohr

A deep truth is a truth so deep that not only is it true but it’s exact opposite is also true. — Niels Bohr

Truth and clarity are complementary. — Niels Bohr

It is the hallmark of any deep truth that its negation is also a deep truth. — Niels Bohr

There are trivial truths and the great truths. The opposite of a trivial truth is plainly false. The opposite of a great truth is also true. — Niels Bohr

You can recognize a small truth because its opposite is a falsehood. The opposite of a great truth is another truth. — Niels Bohr

Truth is something that we can attempt to doubt, and then perhaps, after much exertion, discover that part of the doubt is not justified. — Niels Bohr

Accuracy and clarity of statement are mutually exclusive. — Niels Bohr

Your theory is crazy, but it’s not crazy enough to be true. — Niels Bohr

A person who wasn’t outraged on first hearing about quantum theory didn’t understand what had been said. — Niels Bohr

Every description of natural processes must be based on ideas which have been introduced and defined by the classical theory. — Niels Bohr

We are all agreed that your theory is crazy. The question which divides us is whether it is crazy enough to have a chance of being correct. My own feeling is that it is not crazy enough. — Niels Bohr

There is no hope for any speculation that does not look absurd at first glance. — Niels Bohr

Every valuable human being must be a radical and a rebel, for what he must aim at is to make things better than they are. — Niels Bohr

It is a great pity that human beings cannot find all of their satisfaction in scientific contemplativeness. — Niels Bohr

All rising curves that show unwelcome trends in human affairs will approach infinity if extended far enough, but it is we who dictate the curve and not vice versa. — Niels Bohr

What is that we human beings ultimately depend on? We depend on our words. We are suspended in language. Our task is to communicate experience and ideas to others. — Niels Bohr

The opposite of every great idea is another great idea. — Niels Bohr

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

It is difficult to predict, especially the future. — Niels Bohr

If anybody says he can think about quantum physics without getting giddy, that only shows he has not understood the first thing about them. — Niels Bohr

Stop telling God what to do with his dice. — Niels Bohr

When it comes to atoms, language can be used only as in poetry. — Niels Bohr

Those who are not shocked when they first come across quantum theory cannot possibly have understood it. — Niels Bohr

An independant reality in the ordinary physical sense can neither be ascribed to the phenomenon nor to the agencies of observation. — Niels Bohr

You must come to Copenhagen to work with us. We like people who can actually perform thought experiments! — Niels Bohr

If an idea does not appear bizarre, there is no hope for it. — Niels Bohr

If we couldn’t laugh at ourselves, that would be the end of everything. — Niels Bohr

Some things are so serious, they can only be joked about. — Niels Bohr

There are some things so serious you have to laugh at them. — 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

Anyone who can contemplate quantum mechanics without getting dizzy hasn’t understood it. — Niels Bohr

A physicist is just an atom’s way of looking at itself. — Niels Bohr

If you think you understand it, that only shows that you don’t know the first thing about it. — Niels Bohr

Never express yourself more clearly than you are able to think. — Niels Bohr

If you aren’t confused by quantum mechanics, you haven’t really understood it. — Niels Bohr

If quantum mechanics hasn’t profoundly shocked you, you haven’t understood it yet. — Niels Bohr

No, no, you’re not thinking; you’re just being logical. — Niels Bohr

Anyone who is not shocked by quantum theory has not understood it. — Niels Bohr

Everything we call real is made of things that cannot be regarded as real. If quantum mechanics hasn’t profoundly shocked you, you haven’t understood it yet. — Niels Bohr

And anyone who thinks they can talk about quantum theory without feeling dizzy hasn’t yet understood the first thing about it. — Niels Bohr

Address to Albert Einstein: You are not thinking. You are merely being logical. — Niels Bohr

The meaning of life consists in the fact that it makes no sense to say that life has no meaning. — Niels Bohr

The very fact that knowledge is itself the basis for civilization points directly to openness as the way to overcome the present crisis. — Niels Bohr

One must always do what one really cannot. — Niels Bohr