Werner Heisenberg

"I believe that the present state of knowledge of nuclear physics is such that we have to be very humble."

"The limits of my language mean the limits of my world."

"Only the man who has denied everything can truly believe in everything."

"It is the duty of the scientist to understand the implications of his discoveries."

"The task of science is to reveal nature, not to create it."

"We should not work on semiconductors, that is a filthy mess; who knows whether they really exist."

"The probability of an event represents our degree of knowledge about it."

"The first principle is that you must not fool yourself, and you are the easiest person to fool."

"What we observe is not nature itself, but nature exposed to our method of questioning."

"The atoms or elementary particles themselves are not real; they form a world of potentialities."

"Science cannot solve the ultimate mystery of nature because in the end we ourselves are part of nature."

"An expert is a person who has made all the mistakes that can be made in his field."

"The task is not so much to see what no one has yet seen, but to think what nobody has yet thought."

"What we observe is not nature in itself, but nature exposed to our line of questioning."

"In the history of science, ever since the famous trial of Galileo, it has repeatedly been the church which has insisted that scientists should bow to the blindness of the mob."

"The first gulp from the glass of natural sciences will turn you into an atheist, but at the bottom of the glass God is waiting for you."

"Anybody who comes to a physicist and has read somewhat about modern physics knows that he is in the soup, as the saying goes."

"I have repeatedly said that in my view the message of atomic physics is that no property of a physical object can be defined without specifying the means of observation."

"The atoms or elementary particles are not real; they form a world of potentialities or possibilities rather than one of things or facts."

"To understand a science, it is necessary to know its history."

"A scientist only has the right to make statements about those facts or phenomena that he has thoroughly investigated."

"What can we learn about the world from the fact that we must formulate our knowledge in the form of mathematics?"

"Changes in the concept of reality are changes in the concept of what is real."

"The transition from the elementary particles of modern physics to the macroscopic world of Newton is still mysterious."

"Physics is really nothing more than a sophisticated version of children's play."

"Looking at this world, I feel there is a definite plan, elaborated by an intelligence of superior quality."

"The existing scientific concepts cover always only a very limited part of reality."

"One should as a rule respect public opinion in so far as is necessary to avoid starvation and to prevent oneself from being cast into prison."

"In modern physics, the properties of space and time are no longer independent of the material contents of the universe."

"I believe that the existence of the classical 'path' can no longer be ascribed to the electron."