The ontology of materialism rested upon the illusion that the kind of existence, the direct "actuality" of the world around us, can be extrapolated into the atomic range. This extrapolation is impossible, however.

Nature is made in such a way as to be able to be understood. Or perhaps I should put it-more correctly-the other way around, and say that we are made in such a way as to be able to understand Nature.

Many people will tell you that an expert is someone who knows a great deal about the subject. To this I would object that one can never know much about any subject. I would much prefer the following definition: an expert is someone who knows some of the worst mistakes that can be made in the subject, and how to avoid them.

Natural science, does not simply describe and explain nature; it is part of the interplay between nature and ourselves

You may object that by speaking of simplicity and beauty I am introducing aesthetic criteria of truth, and I frankly admit that I am strongly attracted by the simplicity and beauty of mathematical schemes which nature presents us. You must have felt this too: the almost frightening simplicity and wholeness of the relationship, which nature suddenly spreads out before us.

Whether we electrons, light quanta, benzol molecules, or stones, we shall always come up against these two characteristics, the corpuscular and the undular.

An expert is someone who knows some of the worst mistakes that can be made in his subject and how to avoid them.