It followed from the special theory of relativity that mass and energy are both but different manifestations of the same thing...

Concepts that have proven useful in ordering things easily achieve such authority over us that we forget their earthly origins and accept them as unalterable givens.

In the middle of every difficulty lies opportunity.

Whoever is careless with the truth in small matters cannot be trusted in important affairs.

It is impossible to solve significant problems using the same knowledge that created them.

A religious person is devout in the sense that he has no doubt about the significance of those superpersonal objects and goals which neither require nor are capable of rational foundation

It is my fate to be considered an authority, since I spent my youth rebelling against it.