No path leads from a knowledge of that which is to that which should be.

You can never solve a problem on the level on which it was created. Insanity: doing the same thing over and over again and expecting different results. A life lived for others is a life worthwhile.

No one must think that Newton’s great creation can be overthrown in any real sense by this [Theory of Relativity] or by any other theory. His clear and wide ideas will for ever retain their significance as the foundation on which our modern conceptions of physics have been built.

It is this mythical, or rather symbolic, content of the religious traditions which is likely to come into conflict with science. This occurs whenever this religious stock of ideas contains dogmatically fixed statements on subjects which belong in the domain of science.

The real difficulty, the difficulty which has baffled the sages of all times, is rather this: how can we make our teaching so potent in the motional life of man, that its influence should withstand the pressure of the elemental psychic forces in the individual?

We can invent as many theories we like, and any one of them can be made to fit the facts. But that theory is always preferred which makes the fewest number of assumptions.

The secret to creativity is knowing how to hide your sources.