Werner Heisenberg

"A scientist only has the right to make statements that can be verified by experiment or observation."

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

"In the history of science, ever since the famous trial of Galileo, it has always been the part of the Church to oppose the knowledge of nature in the scientific sense."

"Conservation of energy makes no sense without the concept of time."

"Whenever we proceed from the known into the unknown we may hope to understand, but we may have to learn at the same time a new meaning of the word 'understanding.'"

"The atoms may be thought of as the final units out of which matter is built up."

"The physicist may be satisfied when he can create a superior mechanical model of the phenomena."

"Nature isn't classical, dammit, and if you want to make a simulation of nature, you'd better make it quantum mechanical."

"In the history of human thinking, the most fruitful developments frequently take place at the intersection of two different lines of thought."

"The laws of nature are the canvas God laid down on which he painted his masterpiece."

"I have repeatedly said that in my view the answer to this task can only be spiritual in nature."

"The change from the absolute to the relative theory is the most profound revolution in human thinking."

"Man can embody truth, but he cannot know it."

"The basis of all atomic physics is the Heisenberg uncertainty principle."

"What we actually observe is always a choice between a number of possibilities afforded by nature."

"The more one chases rabbits, the more convinced one becomes that they exist."

"For a parallel between physics and mysticism—both are ultimately concerned with something beyond the reach of ordinary words and concepts."

"Every word or phrase, even the most abstract, has only meaning insofar as we can point to something concrete that it describes."

"The division of the world into subject and object, inner world and outer world, is something we cannot overcome."

"The transition from the possible to the actual takes place as soon as the interaction with the macroscopic world has been carried out."

"If nature leads us to mathematical forms of great simplicity and beauty—by forms I am referring to coherent systems of hypothesis, axioms, etc.—to me this is equivalent to a act of faith in God."

"New scientific truth does not triumph by convincing opponents, but rather because opponents eventually die, and a new generation grows up that is familiar with it."

"The chain of reasoning which led me to formulate the principle of indeterminacy was as follows."

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

"All science is rooted in a few axioms and intuitive concepts."

"The laws of nature are not only the expression of regularities, but also of definite restrictions."

"What is important is not the knowledge itself, but the process of acquiring it."

"Whenever we get a picture of the world, it is our picture of the world."

"The idea of the quantum came into physics as a sort of miracle."

"Suppose we imagine two positions, 10 and 1. Well, we might as well imagine them as 100 and 1. The ratio is still the same."