First Quote Added
April 10, 2026
Latest Quote Added
"Shut up and calculate!"
"Do not read so much, look about you and think of what you see there."
"The worthwhile problems are the ones you can really solve or help solve, the ones you can really contribute something to. … No problem is too small or too trivial if we can really do something about it. You say you are a nameless man. You are not to your wife and to your child. You will not long remain so to your immediate colleagues if you can answer their simple questions when they come into your office. You are not nameless to me. Do not remain nameless to yourself — it is too sad a way to be. Know your place in the world and evaluate yourself fairly, not in terms of the naïve ideals of your own youth, nor in terms of what you erroneously imagine your teacher's ideals are."
"[S]tudy hard what interests you the most in the most undisciplined, irreverent and original manner possible."
"D’Arline,I adore you, sweetheart. I know how much you like to hear that—but I don’t only write it because you like it—I write it because it makes me warm all over inside to write it to you. It is such a terribly long time since I last wrote to you—almost two years but I know you’ll excuse me because you understand how I am, stubborn and realistic; and I thought there was no sense to writing. But now I know my darling wife that it is right to do what I have delayed in doing, and what I have done so much in the past. I want to tell you I love you. I want to love you—I always will love you. I find it hard to understand in my mind what it means to love you after you are dead—but I still want to comfort and take care of you—and I want you to love me and care for me. I want to have problems to discuss with you—I want to do little projects with you. I never thought until just now that we can do that together. What should we do. We started to learn to make clothes together—or learn Chinese—or getting a movie projector. Can’t I do something now. No. I am alone without you and you were the "idea-woman" and general instigator of all our wild adventures. When you were sick you worried because you could not give me something that you wanted to and thought I needed. You needn't have worried. Just as I told you then there was no real need because I loved you in so many ways so much. And now it is clearly even more true—you can give me nothing now yet I love you so that you stand in my way of loving anyone else—but I want to stand there. You, dead, are so much better than anyone else alive. I know you will assure me that I am foolish and that you want me to have full happiness and don’t want to be in my way. I’ll bet that you are surprised that I don’t even have a girlfriend (except you, sweetheart) after two years. But you can’t help it, darling, nor can I—I don’t understand it, for I have met many girls and very nice ones and I don’t want to remain alone—but in two or three meetings they all seem ashes. You only are left to me. You are real.My darling wife, I do adore you.I love my wife. My wife is dead.RichP.S. Please excuse my not mailing this—but I don’t know your new address."
"I don't know anything, but I do know that everything is interesting if you go into it deeply enough."
"...In that same period there was Newton, there was Harvey studying the circulation of the blood, there were people with methods of analysis by which progress was being made! You can take every one of Spinoza's propositions and take the contrary propositions and look at the world--and you can't tell which is right. Sure, people were awed because he had the courage to take on these great questions, but it doesn't do any good to have the courage if you can't get anywhere with the question..."
"...I don't believe in the idea that there are a few peculiar people capable of understanding math and the rest of the world is normal. Math is a human discovery, and it's no more complicated than humans can understand. I had a calculus book once that said, "What one fool can do, another fool can." What we've been able to work out about nature may look abstract and threatening to someone who hasn't studied it, but it was fools who did it, and in the next generation, all the fools will understand it. There's a tendency to pomposity in all this, to make it all deep and profound..."
"We absolutely must leave room for doubt or there is no progress and no learning. There is no learning without having to pose a question. And a question requires doubt. People search for certainty. But there is no certainty. People are terrified — how can you live and not know? It is not odd at all. You only think you know, as a matter of fact. And most of your actions are based on incomplete knowledge and you really don't know what it is all about, or what the purpose of the world is, or know a great deal of other things. It is possible to live and not know."
"The remark which I read somewhere, that science is all right as long as it doesn't attack religion, was the clue I needed to understand the problem. As long as it doesn't attack religion it need not be paid attention to and nobody has to learn anything. So it can be cut off from society except for its applications, and thus be isolated. And then we have this terrible struggle to try to explain things to people who have no reason to want to know. But if they want to defend their own point of view, they will have to learn what yours is a little bit. So I suggest, maybe correctly and perhaps wrongly, that we are too polite."
"I've always been rather very one-sided about the science, and when I was younger, I concentrated almost all my effort on it. I didn't have time to learn, and I didn't have much patience for what's called the humanities; even though in the university there were humanities that you had to take, I tried my best to avoid somehow to learn anything and to work on it. It's only afterwards, when I've gotten older and more relaxed that I've spread out a little bit — I've learned to draw, and I read a little bit, but I'm really still a very one-sided person and don't know a great deal. I have a limited intelligence and I've used it in a particular direction."
"Suppose two politicians are running for president, and one goes through the farm section and is asked, "What are you going to do about the farm question?" And he knows right away - bang, bang, bang. Now he goes to the next campaigner who comes through. "What are you going to do on the farm problem?" "Well, I don't know. I used to be a general, and I don't know anything about farming. But it seems to me it must be a very difficult problem, because for twelve, fifteen, twenty years people have been struggling with it, and people say that they know how to solve the farm problem. And it must be a hard problem. So the way I intend to solve the farm problem is to gather around me a lot of people who know something about it, to look at all the experience that we have had with this problem before, to take a certain amount of time at it, and then to come to some conclusion in a reasonable way about it. Now, I can't tell you ahead of time what solution, but I can give you some of the principles I'll try to use - not to make things difficult for individual farmers, if there are any special problems we will have to have some way to take care of them," etc., etc., etc. Now such a man would never get anywhere in this country, I think. It's never been tried, anyway. This is in the attitude of mind of the populace, that they have to have an answer and that a man who gives an answer is better than a man who gives no answer, when the real fact of the matter is, in most cases, it is the other way around. And the result of this of course is that the politician must give an answer. And the result of this is that political promises can never be kept. It is a mechanical fact; it is impossible. The result of that is that nobody believes campaign promises. And the result of that is a general disparaging of politics, a general lack of respect for the people who are trying to solve problems, and so forth. It's all generated from the very beginning (maybe - this is a simple analysis). It's all generated, maybe, by the fact that the attitude of the populace is to try to find the answer instead of trying to find a man who has a way of getting at the answer."
"If the professors of English will complain to me that the students who come to the universities, after all those years of study, still cannot spell "friend," I say to them that something's the matter with the way you spell friend."
"It's a great game to try to look at the past, at an unscientific era, look at something there, and say have we got the same thing now, and where is it? So I would like to amuse myself with this game. First, we take witch doctors. The witch doctor says he knows how to cure. There are spirits inside which are trying to get out. ... Put a snakeskin on and take quinine from the bark of a tree. The quinine works. He doesn't know he's got the wrong theory of what happens. If I'm in the tribe and I'm sick, I go to the witch doctor. He knows more about it than anyone else. But I keep trying to tell him he doesn't know what he's doing and that someday when people investigate the thing freely and get free of all his complicated ideas they'll learn much better ways of doing it. Who are the witch doctors? Psychoanalysts and psychiatrists, of course."
"Anyway, I have to argue about flying saucers on the beach with people, you know. And I was interested in this: they keep arguing that it is possible. And that's true. It is possible. They do not appreciate that the problem is not to demonstrate whether it's possible or not but whether it's going on or not."
"The first one has to do with whether a man knows what he is talking about, whether what he says has some basis or not. And my trick that I use is very easy. If you ask him intelligent questions — that is, penetrating, interested, honest, frank, direct questions on the subject, and no trick questions — then he quickly gets stuck. It is like a child asking naive questions. If you ask naive but relevant questions, then almost immediately the person doesn't know the answer, if he is an honest man."
"I believe in limited government. I believe that government should be limited in many ways, and what I am going to emphasize is only an intellectual thing. I don't want to talk about everything at the same time. Let's take a small piece, an intellectual thing.No government has the right to decide on the truth of scientific principles, nor to prescribe in any way the character of the questions investigated. Neither may a government determine the aesthetic value of artistic creations, nor limit the forms of literary or artistic expression. Nor should it pronounce on the validity of economic, historic, religious, or philosophical doctrines. Instead it has a duty to its citizens to maintain the freedom, to let those citizens contribute to the further adventure and the development of the human race."
"The fact that you are not sure means that it is possible that there is another way someday."
"It is a great adventure to contemplate the universe, beyond man, to contemplate what it would be like without man, as it was in a great part of its long history and as it is in a great majority of places. When this objective view is finally attained, and the mystery and majesty of matter are fully appreciated, to then turn the objective eye back on man viewed as matter, to view life as part of this universal mystery of greatest depth, is to sense an experience which is very rare, and very exciting. It usually ends in laughter and a delight in the futility of trying to understand what this atom in the universe is, this thing — atoms with curiosity — that looks at itself and wonders why it wonders. Well, these scientific views end in awe and mystery, lost at the edge in uncertainty, but they appear to be so deep and so impressive that the theory that it is all arranged as a stage for God to watch man's struggle for good and evil seems inadequate."
"It is in the admission of ignorance and the admission of uncertainty that there is a hope for the continuous motion of human beings in some direction that doesn't get confined, permanently blocked, as it has so many times before in various periods in the history of man."
"Looking back at the worst times, it always seems that they were times in which there were people who believed with absolute faith and absolute dogmatism in something. And they were so serious in this matter that they insisted that the rest of the world agree with them. And then they would do things that were directly inconsistent with their own beliefs in order to maintain that what they said was true."
"Some people say, "How can you live without knowing?" I do not know what they mean. I always live without knowing. That is easy. How you get to know is what I want to know."
"The third aspect of my subject is that of science as a method of finding things out. This method is based on the principle that observation is the judge of whether something is so or not. All other aspects and characteristics of science can be understood directly when we understand that observation is the ultimate and final judge of the truth of an idea. But "prove" used in this way really means "test," in the same way that a hundred-proof alcohol is a test of the alcohol, and for people today the idea really should be translated as, "The exception tests the rule." Or, put another way, "The exception proves that the rule is wrong." That is the principle of science. If there is an exception to any rule, and if it can be proved by observation, that rule is wrong."
"Jiry, don't worry about anything. Go out and have a good time."
"People say to me, "Are you looking for the ultimate laws of physics?" No, I'm not. I'm just looking to find out more about the world and if it turns out there is a simple ultimate law which explains everything, so be it; that would be very nice to discover. If it turns out it's like an onion with millions of layers and we're just sick and tired of looking at the layers, then that's the way it is!... And therefore when we go to investigate we shouldn't pre-decide what it is we are trying to do except to find out more about it... My interest in science is to simply find out more about the world."
"I can live with doubt, and uncertainty, and not knowing. I think it's much more interesting to live not knowing than to have answers which might be wrong. I have approximate answers, and possible beliefs, and different degrees of certainty about different things, but I'm not absolutely sure of anything. There are many things I don't know anything about, such as whether it means anything to ask "Why are we here?" I might think about it a little bit, and if I can't figure it out then I go on to something else. But I don't have to know an answer. I don't feel frightened by not knowing things, by being lost in the mysterious universe without having any purpose — which is the way it really is, as far as I can tell. Possibly. It doesn't frighten me."
"Well, we're getting a little philosophical and serious, ok? Let's go back to what we're doing. One day we look at a map and this capital is K-Y-Z-Y-L and we decided it would be fun to go there because it's so obscure and peculiar. It's a game. It's not serious. It doesn't involve some deep philosophical point of view about authority or anything. It's just the fun of having an adventure to try to go to a land that we'd never heard of, that we knew was an independent country once, no longer an independent country, find out what it's like. And discover as we went along that nobody went there for a long time and it's isolated made it more interesting. But, you know, many explorers liked to go to places that are unusual. And, it's only for the fun of it. I don't go for this philosophical interpretation of "our deeper understanding of what we’re doing." We haven't any deep understanding of what we're doing. If we tried to understand what we're doing, we'd go nutty."
"I don't like honors. ... I've already got the prize: the prize is the pleasure of finding the thing out, the kick in the discovery, the observation that other people use it. Those are the real things."
"The most important thing I found out from [my father] is that if you asked any question and pursued it deeply enough, then at the end there was a glorious discovery of a general and beautiful kind."
"The only way to have real success in science, the field I'm familiar with, is to describe the evidence very carefully without regard to the way you feel it should be. If you have a theory, you must try to explain what's good and what's bad about it equally. In science, you learn a kind of standard integrity and honesty."
"The real question of government versus private enterprise is argued on too philosophical and abstract a basis. Theoretically, planning may be good. But nobody has ever figured out the cause of government stupidity — and until they do (and find the cure), all ideal plans will fall into quicksand."
"Doubting the great Descartes ... was a reaction I learned from my father: Have no respect whatsoever for authority; forget who said it and instead look what he starts with, where he ends up, and ask yourself, "Is it reasonable?""
"My mother ... had a wonderful sense of humor, and I learned from her that the highest forms of understanding we can achieve are laughter and human compassion."
"You can know the name of that bird in all the languages of the world, but when you're finished, you'll know absolutely nothing whatever about the bird. You'll only know about humans in different places, and what they call the bird. ... I learned very early the difference between knowing the name of something and knowing something."
"I have a friend who's an artist, and he sometimes takes a view which I don't agree with. He'll hold up a flower and say, "Look how beautiful it is," and I'll agree. But then he'll say, "I, as an artist, can see how beautiful a flower is. But you, as a scientist, take it all apart and it becomes dull." I think he's kind of nutty. ... There are all kinds of interesting questions that come from a knowledge of science, which only adds to the excitement and mystery and awe of a flower. It only adds. I don't understand how it subtracts."
"Let us make recommendations to ensure that NASA officials deal in a world of reality in understanding technological weaknesses and imperfections well enough to be actively trying to eliminate them. They must live in reality in comparing the costs and utility of the Shuttle to other methods of entering space. And they must be realistic in making contracts, in estimating costs, and the difficulty of the projects. Only realistic flight schedules should be proposed, schedules that have a reasonable chance of being met. If in this way the government would not support them, then so be it. NASA owes it to the citizens from whom it asks support to be frank, honest, and informative, so that these citizens can make the wisest decisions for the use of their limited resources. For a successful technology, reality must take precedence over public relations, for nature cannot be fooled."
"There was no way, without full understanding, that one could have confidence that conditions the next time might not produce erosion three times more severe than the time before. Nevertheless, officials fooled themselves into thinking they had such understanding and confidence, in spite of the peculiar variations from case to case. A mathematical model was made to calculate erosion. This was a model based not on physical understanding but on empirical curve fitting."
"The acceptance and success of these flights is taken as evidence of safety. But erosion and blow-by are not what the design expected. They are warnings that something is wrong. The equipment is not operating as expected, and therefore there is a danger that it can operate with even wider deviations in this unexpected and not thoroughly understood way. The fact that this danger did not lead to a catastrophe before is no guarantee that it will not the next time, unless it is completely understood. When playing Russian roulette the fact that the first shot got off safely is little comfort for the next. The origin and consequences of the erosion and blow-by were not understood. They did not occur equally on all flights and all joints; sometimes more, and sometimes less. Why not sometime, when whatever conditions determined it were right, still more leading to catastrophe? In spite of these variations from case to case, officials behaved as if they understood it, giving apparently logical arguments to each other often depending on the "success" of previous flights."
"If we are to replace standard numerical probability usage with engineering judgment, why do we find such an enormous disparity between the management estimate and the judgment of the engineers? It would appear that, for whatever purpose, be it for internal or external consumption, the management of NASA exaggerates the reliability of its product, to the point of fantasy."
"It appears that there are enormous differences of opinion as to the probability of a failure with loss of vehicle and of human life. The estimates range from roughly 1 in 100 to 1 in 100,000. The higher figures come from the working engineers, and the very low figures from management. What are the causes and consequences of this lack of agreement? Since 1 part in 100,000 would imply that one could put a Shuttle up each day for 300 years expecting to lose only one, we could properly ask "What is the cause of management's fantastic faith in the machinery?" We have also found that certification criteria used in Flight Readiness Reviews often develop a gradually decreasing strictness. The argument that the same risk was flown before without failure is often accepted as an argument for the safety of accepting it again. Because of this, obvious weaknesses are accepted again and again, sometimes without a sufficiently serious attempt to remedy them, or to delay a flight because of their continued presence."
"So I have just one wish for you—the good luck to be somewhere where you are free to maintain the kind of integrity I have described, and where you do not feel forced by a need to maintain your position in the organization, or financial support, or so on, to lose your integrity. May you have that freedom."
"On the contrary, it's because somebody knows something about it that we can't talk about physics. It's the things that nobody knows anything about that we can discuss. We can talk about the weather; we can talk about social problems; we can talk about psychology; we can talk about international finance — gold transfers we can't talk about, because those are understood — so it's the subject that nobody knows anything about that we can all talk about!"
"Ordinary fools are all right; you can talk to them, and try to help them out. But pompous fools—guys who are fools and are covering it all over and impressing people as to how wonderful they are with all this hocus pocus—THAT, I CANNOT STAND! An ordinary fool isn’t a faker; an honest fool is all right. But a dishonest fool is terrible!"
"This conference was worse than a Rorschach test: There's a meaningless inkblot, and the others ask you what you think you see, but when you tell them, they start arguing with you!"
"I wanted very much to learn to draw, for a reason that I kept to myself: I wanted to convey an emotion I have about the beauty of the world. It's difficult to describe because it's an emotion. It's analogous to the feeling one has in religion that has to do with a god that controls everything in the whole universe: there's a generality aspect that you feel when you think about how things that appear so different and behave so differently are all run "behind the scenes" by the same organization, the same physical laws. It's an appreciation of the mathematical beauty of nature, of how she works inside; a realization that the phenomena we see result from the complexity of the inner workings between atoms; a feeling of how dramatic and wonderful it is. It's a feeling of awe — of scientific awe — which I felt could be communicated through a drawing to someone who had also had this emotion. It could remind him, for a moment, of this feeling about the glories of the universe."
"I'll never make that mistake again, reading the experts' opinions. Of course, you only live one life, and you make all your mistakes, and learn what not to do, and that's the end of you."
"Since then I never pay attention to anything by "experts". I calculate everything myself."
"While in Kyoto I tried to learn Japanese with a vengeance. I worked much harder at it, and got to a point where I could go around in taxis and do things. I took lessons from a Japanese man every day for an hour. One day he was teaching me the word for "see." "All right," he said. "You want to say, 'May I see your garden?' What do you say?" I made up a sentence with the word that I had just learned. "No, no!" he said. "When you say to someone, 'Would you like to see my garden?' you use the first 'see.' But when you want to see someone else's garden, you must use another 'see,' which is more polite." "Would you like to glance at my lousy garden?" is essentially what you're saying in the first case, but when you want to look at the other fella's garden, you have to say something like, "May I observe your gorgeous garden?" So there's two different words you have to use. Then he gave me another one: "You go to a temple, and you want to look at the gardens..." I made up a sentence, this time with the polite "see." "No, no!" he said. "In the temple, the gardens are much more elegant. So you have to say something that would be equivalent to 'May I hang my eyes on your most exquisite gardens?" Three or four different words for one idea, because when I'm doing it, it's miserable; when you're doing it, it's elegant. I was learning Japanese mainly for technical things, so I decided to check if this same problem existed among the scientists. At the institute the next day, I said to the guys in the office, "How would I say in Japanese, 'I solve the Dirac Equation'?" They said such-and-so. "OK. Now I want to say, 'Would you solve the Dirac Equation?' — how do I say that?" "Well, you have to use a different word for 'solve,' " they say. "Why?" I protested. "When I solve it, I do the same damn thing as when you solve it!" "Well, yes, but it's a different word — it's more polite." I gave up. I decided that wasn't the language for me, and stopped learning Japanese."
"I have to understand the world, you see."
"Finally, I said that I couldn’t see how anyone could be educated by this self-propagating system in which people pass exams, and teach others to pass exams, but nobody knows anything."