Feynman, Richard

"The value of science is in the training of the mind to think something like nature thinks."

"I don't know what's the matter with people: they don't learn by understanding; they learn by some other way."

"The principle of quantum mechanics is this: the thing that makes it different from the classical is the superposition principle."

"I find that I don't understand things unless I try to explain them."

"Some people say, 'How do you know you're not crazy?' I don't know how to answer that."

"One of the most important principles for the development of a science is the recognition of the ignorance and the doubt."

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

"Science is the belief in the ignorance of experts."

"What I cannot create, I do not understand."

"The principle of science is that all knowledge must be in doubt."

"I would rather have questions that can't be answered than answers that can't be questioned."

"There are 10^11 stars in the galaxy. That used to be a huge number. But it's only a hundred billion. It's less than the national deficit!"

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

"The highest forms of understanding we can achieve are laughter and human compassion."

"For a successful technology, reality must take precedence over public relations, for nature cannot be fooled."

"You don't have to know that something called the 'Atom' exists to talk about people humping in the street."

"I learned very early the difference between knowing the name of something and knowing something."

"The pleasure of finding things out is enough for me."

"Curiosity is the only thing that may be as important as the ability to see things clearly."

"If you want to master something, teach it."

"The effort to think clearly about the world is the beginning of all knowledge."

"I don't like honors. I'm better when I don't have honors."

"You see, one thing is, I can live with doubt and uncertainty and not knowing. I think it is much more interesting to live not knowing than to have answers which might be wrong."

"Physics is really nothing more than a search for ultimate simplicity, but so far all we have is a kind of elegant messiness."

"I think it is far better to grasp the Universe as it really is than to persist in delusion, however satisfying and reassuring."

"The value of science remains unsung by singers, so you are reduced to hearing – not a song or poem, but an evening lecture about it."

"The real problem in speaking is that not a sound ever comes out of my mouth the same way twice."

"What is and what should never be are two entirely different things in nature."

"I would advise you not to undertake to predict the results of any quantum mechanical experiment."

"The test of all knowledge is experiment. Experiment is the sole judge of scientific truth."