[S]ymbols have a reach and a roundness that goes beyond their literal and practical meaning. They are the rich concepts under which the mind gathers … - Jacob Bronowski

Positivists and analysts alike believe that the words is and ought belong to different worlds, so that sentences which are constructed with is usually have verifiable meaning, but sentences constructed with ought never have. This is because Ludwig Wittgenstein's unit, and Bertrand Russell's unit, is one man; all British empiricist philosophy is individualist. And it is of course clear that if the only criterion of true and false which a man accepts is that man's, then he has no base for social agreement. The question of how man ought to behave is a social question, which always involves several people; and if he accepts no evidence and no judgment except his own, he has no tools with which to frame an answer.

The force that makes the winter grow Its feathered hexagons of snow, and drives the bee to match at home Their calculated honeycomb, Is abacus and rose combined. An icy sweetness fills my mind, A sense that under thing and wing Lies, taut yet living, coiled, the spring.

I have chosen to talk about one of the founder fathers of twentieth-century physics, Niels Bohr, because in both these respects he was a consummate artist. He had no ready-made answers. He used to begin his lecture courses by saying to his students, ‘Every sentence that I utter should be regarded by you not as an assertion but as a question’. What he questioned was the structure of the world. And the people that he worked with, when young and old (he was still penetrating in his seventies), were others who were taking the world to pieces, thinking it out, and putting it together.