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.

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

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

One thought spectra are marvellous, but it is not possible to make progress there. Just as if you have the wing of a butterfly then certainly it is very regular with the colors and so on, but nobody thought one could get the basis of biology from the coloring of the wing of a butterfly.

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

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

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