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.

I never really expected to be controversial.

The people who control the condition in which we live have no reason to think beyond more than the next five or 10 years.

Great scientific contributions have been techniques.

Reinforcement is being right.

I'm very pessimistic.

Properly used, positive reinforcement is extremely powerful.

The environment shapes people's actions.

The world’s a poor standard. any society which is free of hunger and violence looks bright against that background.

The one fact that I would cry form every housetop is this: the Good Life is waiting for us – here and now.