Any schemes - such as 'think of symmetry laws', or 'put the information in mathematical form', or 'guess equations'- are known to everybody now, and they are all tried all the time. When you are stuck, the answer cannot be one of these, because you will have tried these right away...The next scheme, the new discovery, is going to be made in a completely different way.

As usual, nature's imagination far surpasses our own, as we have seen from the other theories which are subtle and deep.

I have a limited intelligence and I've used it in a particular direction.

If you think you understand quantum mechanics, you don't understand quantum mechanics.

The unanswerable mysteries... the attitude that all is uncertain... to summarize it - the humility of the intellect.

If there is something very slightly wrong in our definition of the theories, then the full mathematical rigor may convert these errors into ridiculous conclusions.

In fact the total amount that a physicist knows is very little. He has only to remember the rules to get him from one place to another and he is all right.