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.

A popular cliche in philosophy says that science is pure analysis or reductionism, like taking the rainbow to pieces; and art is pure synthesis, putting the rainbow together. This is not so. All imagination begins by analyzing nature.

The idea that the universe is running down comes from a simple observation about machines. Every machine consumes more energy than it renders.

A genius is a man who has two great ideas.

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

Ask an impertinent question and you are on the way to the pertinent answer.

Knowledge is not a loose leaf notebook of facts.