As our circle of knowledge expands, so does the circumference of darkness surrounding it.

You can never solve a problem on the level on which it was created.

If I had an hour to solve a problem and my life depended on the solution, I would spend the first 55 minutes determining the proper question to ask, for once I know the proper question, I could solve the problem in less than five minutes.

There comes a point in your life when you need to stop reading other people's books and write your own.

The thinking it took to get us into this mess is not the same thinking that is going to get us out of it.

What we don't know is much more than what we know.

There are few enough people with sufficient independence to see the weaknesses and follies of their contemporaries and remain themselves untouched by them.