"If a man is to be a good physicist, he must have an intuitive grasp of the physical reality, which can be acquired only by much experience."

"The history of physics is not only a sequence of experimental discoveries and observations, but also a history of concepts."

"The path to the new physics was paved by the discovery of the quantum of action."

"One day, when we have learned to understand the elementary particles, we will have understood the whole world."

"The world of atoms is a world of possibilities and not a world of things."