The more we learn the more we realize how little we know.

Now there is one outstanding important fact regarding spaceship earth, and that is that no instruction book came with it.

The earth is like a spaceship that didn't come with an operating manual.

However, if we leave the industrial machinery and their energy-distribution networks and leave them also all the people who have routine jobs operating the industrial machinery and distributing its products, and we take away from all the industrial countries all their ideologies and all the politicians and political machine workers, people would keep right on eating. Possibly getting on a little better than before.

Controlled time is our true wealth.

I do not look upon human beings as good or bad.

By and large, I seem to have made more mistakes than any others of whom I know, but have learned thereby to make ever swifter acknowledgment of the errors and thereafter immediately set about to deal more effectively with the truths disclosed by the acknowledgment of erroneous assumptions.