One aim of physical sciences had been to give an exact picture the material world. One achievement of physics in the twentieth century has been to prove that that aim is unattainable.

The world is made up of people who never quite get into the first team and who just miss the prizes at the flower show.

But nature - that is, biological evolution - has not fitted man to any specific environment. On the contrary, ... he has a rather crude survival kit; and yet -this is the paradox of the human condition - one that fits him to all environments. Among the multitude of animals which scamper, fly, burrow and swim around us, man is the only one who is not locked into his environment. His imagination, his reason, his emotional subtlety and toughness, make it possible for him not to accept the environment but to change it.

There is no absolute knowledge. And those who claim it, whether they are scientists or dogmatists, open the door to tragedy.

Science is the acceptance of what works and the rejection of what does not. That needs more courage than we might think.

One aim of physical sciences had been to give an exact picture the material world. One achievement of physics in the twentieth century has been to prove that that aim is unattainable.

Man is a singular creature. He has a set of gifts which make him unique among the animals, so that unlike them, he is not a figure in the landscape, he is the shaper of the landscape.