“The scientist has a lot of experience with ignorance and doubt and uncertainty, and this experience is of very great importance, I think. When a scientist doesn’t know the answer to a problem, he is ignorant. When he has a hunch as to what the result is, he is uncertain. And when he is pretty damn sure of what the result is going to be, he is still in some doubt. We have found it of paramount importance that in order to progress, we must recognize our ignorance and leave room for doubt. Scientific knowledge is a body of statements of varying degrees of certainty — some most unsure, some nearly sure, but none absolutely certain. Now, we scientists are used to this, and we take it for granted that it is perfectly consistent to be unsure, that it is possible to live and not know. But I don’t know whether everyone realizes this is true. Our freedom to doubt was born out of a struggle against authority in the early days of science. It was a very deep and strong struggle: permit us to question — to doubt — to not be sure. I think that it is important that we do not forget this struggle and thus perhaps lose what we have gained.”

“A few years after I gave some lectures for the freshmen at Caltech (which were published as the Feynman Lectures on Physics), I received a long letter from a feminist group. I was accused of being anti-women because of two stories: the first was a discussion of the subtleties of velocity, and involved a woman driver being stopped by a cop. There's a discussion about how fast she was going, and I had her raise valid objections to the cop's definitions of velocity. The letter said I was making the women look stupid. The other story they objected to was told by the great astronomer Arthur Eddington, who had just figured out that the stars get their power from burning hydrogen in a nuclear reaction producing helium. He recounted how, on the night after his discovery, he was sitting on a bench with his girlfriend. She said, "Look how pretty the stars shine!" To which he replied, "Yes, and right now, I'm the only man in the world who knows how they shine." He was describing a kind of wonderful loneliness you have when you make a discovery. The letter claimed that I was saying a women is incapable of understanding nuclear reactions. I figured there was no point in trying to answer their accusations in detail, so I wrote a short letter back to them: "Don't bug me, Man!”

“Take this neat little equation here. It tells me all the ways an electron can make itself comfortable in or around an atom. That's the logic of it. The poetry of it is that the equation tells me how shiny gold is, how come rocks are hard, what makes grass green, and why you can't see the wind. And a million other things besides, about the way nature works.”

“THE QUESTION IS, OF COURSE, IS IT GOING TO BE POSSIBLE TO AMALGAMATE EVERYTHING,AND MERELY DISCOVER THAT THIS WORLD REPRESENTS DIFFERENT ASPECTS OF ONE THING?”

“CURIOSITY DEMANDS THAT WE ASK QUESTIONS,THAT WE TRY TO PUT THINGS TOGETHER AND TRY TO UNDERSTAND THIS MULTITUDE OF ASPECTSAS PERHAPS RESULTING FROM THE ACTION OF A RELATIVELY SMALL NUMBER OF ELEMENTALTHINGS AND FORCES ACTING IN AN INFINITE VARIETY OF COMBINATIONS”

“I noticed that the [drawing] teacher didn't tell people much... Instead, he tried to inspire us to experiment with new approaches. I thought of how we teach physics: We have so many techniques - so many mathematical methods - that we never stop telling the students how to do things. On the other hand, the drawing teacher is afraid to tell you anything. If your lines are very heavy, the teacher can't say, "Your lines are too heavy." because *some* artist has figured out a way of making great pictures using heavy lines. The teacher doesn't want to push you in some particular direction. So the drawing teacher has this problem of communicating how to draw by osmosis and not by instruction, while the physics teacher has the problem of always teaching techniques, rather than the spirit, of how to go about solving physical problems.”

“Until I was twenty I was sure there was a being who could see everything I did and who didn't like most of it. He seemed to care about minute aspects of my life, like on what day of the week I ate a piece of meat. And yet, he let earthquakes and mudslides take out whole communities, apparently ignoring the saints among them who ate their meat on the assigned days. Eventually, I realized that I didn't believe there was such a being. It didn't seem reasonable. And I assumed that I was an atheist.As I understood the word, it meant that I was someone who didn't believe in a God; I was without a God. I didn't broadcast this in public because I noticed that people who do believe in a god get upset to hear that others don't. (Why this is so is one of the most pressing of human questions, and I wish a few of the bright people in this conversation would try to answer it through research.)But, slowly I realized that in the popular mind the word atheist was coming to mean something more - a statement that there couldn't be a God. God was, in this formulation, not possible, and this was something that could be proved. But I had been changed by eleven years of interviewing six or seven hundred scientists around the world on the television program Scientific American Frontiers. And that change was reflected in how I would now identify myself.The most striking thing about the scientists I met was their complete dedication to evidence. It reminded me of the wonderfully plainspoken words of Richard Feynman who felt it was better not to know than to know something that was wrong.”

“I believe that a scientist looking at nonscientific problems is just as dumb as the next guy.”

“Nature has a great simplicity and therefore a great beauty”

“I don't mind not knowing. It doesn't scare me.”

“I think nature's imagination Is so much greater than man's, she's never going to let us relax”