I've had only one idea in my life - a true idee fixe. To put it as bluntly as possible - the idea of having my own way. 'Control!' expresses it. The control of human behavior. In my early experimental days it was a frenzied, selfish desire to dominate. I remember the rage I used to feel when a prediction went awry. I could have shouted at the subjects of my experiments, 'Behave, damn you! Behave as you ought!

A failure is not always a mistake, it may simply be the best one can do under the circumstances. The real mistake is to stop trying.

A scientist may not be sure of the answer, but he's often sure he can find one. And that's a condition which is clearly not enjoyed by philosophy.

It is not a question of starting. The start has been made. It's a question of what's to be done from now on.

Old age is rather like another country. You will enjoy it more if you have prepared yourself before you go.

Must we wait for selection to solve the problems of overpopulation, exhaustion of resources, pollution of the environment and a nuclear holocaust, or can we take explicit steps to make our future more secure? In the latter case, must we not transcend selection?

An important fact about verbal behavior is that speaker and listener may reside within the same skin.