“Isolated material particles are abstractions, their properties being definable and observable only through their interaction with other systems .”

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

No paradox, no progress.

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.

Opposites are not contradictory but complementary.

The present state of atomic theory is characterized by the fact that we not only believe the existence of atoms to be proved beyond a doubt, but also we even believe that we have an intimate knowledge of the constituents of the individual atoms.

Oh what idiots we have all been, this is just as it must be.

Predition is risky, especially of the future.

Truth and clarity are complementary.

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

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

In the great drama of existence we are audience and actors at the same time.

We are trapped by language to such a degree that every attempt to formulate insight is a play on words.

The great extension of our experience in recent years has brought light to the insufficiency of our simple mechanical conceptions and, as a consequence, has shaken the foundation on which the customary interpretation of observation was based.

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

The measurement we get when we measure something is not a property of the thing measured.

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

An idea, like a machine, must have power applied to it before it can accomplish anything.

Money may be the husk of many things but not the kernel. It brings you food, but not appetite; medicine, but not health; acquaintance, but not friends; servants, but not loyalty; days of joy, but not peace or happiness.

Once you start rewriting, you’re not able to stop. With each draft the fundamental banality and worthlessness of the material becomes more evident even as its vitality and spontaneity are drained from it.

A book is a box brimming with incendiary material. The reader strikes the match.

There is but one means available to improve the material conditions of mankind: to accelerate the growth of capital accumulated as against the growth in population.

What makes photography a strange invention is that its primary raw materials are light and time.

The fictional treatment of biographical material – a treatment that for me is essential – is full of traps.

Man’s material discoveries have outpaced his moral progress.