We have to understand that the world can only be grasped by action, not by contemplation. The hand is more important than the eye ... The hand is the cutting edge of the mind.

Whether our work is art or science or the daily work of society, it is only the form in which we explore our experience which is different.

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.

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

The richness of human life is that we have many lives, we live the events that do not happen (and some that cannot) as vividly as those that do, and if thereby we die a thousand deaths, that is the price we pay...

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

The air in a man's lungs 10,000,000,000, 000,000,000,000 atoms, so that sooner or later every one of us breathes an atom that has been breathed before by anyone you can think of who has ever lived - Michelangelo or George Washington or Moses.