Richard Feynman

When it came time for me to give my talk on the subject, I started off by drawing an outline of the cat and began to name the various muscles.The other students in the class interrupt me: "We *know* all that!""Oh," I say, "you *do*? Then no *wonder* I can catch up with you so fast after you've had four years of biology." They had wasted all their time memorizing stuff like that, when it could be looked up in fifteen minutes.

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

Science is like sex: sometimes something useful comes out, but that is not the reason we are doing it.

What I am going to tell you about is what we teach our physics students in the third or fourth year of graduate school... It is my task to convince you not to turn away because you don't understand it. You see my physics students don't understand it... That is because I don't understand it. Nobody does.

Physics is like sex: sure, it may give some practical results, but that's not why we do it.

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

Religion is a culture of faith science is a culture of doubt.

If you thought that science was certain - well, that is just an error on your part.

We are trying to prove ourselves wrong as quickly as possible, because only in that way can we find progress.

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

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

All the time you're saying to yourself, 'I could do that, but I won't,' _ which is just another way of saying that you can't.

You can know the name of a bird in all the languages of the world, but when you're finished, you'll know absolutely nothing whatever about the bird... So let's look at the bird and see what it's doing -- that's what counts.

How you get to know is what I want to know.

We absolutely must leave room for doubt or there is no progress and there is 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.

Science is what we have learned about how to keep from fooling ourselves.

We are at the very beginning of time for the human race. It is not unreasonable that we grapple with problems. But there are tens of thousands of years in the future. Our responsibility is to do what we can, learn what we can, improve the solutions, and pass them on.

Many races as well as cultural influences of men of all kinds have mixed into any man. To select, for approbation the peculiar elements that come from some supposedly Jewish heredity is to open the door to all kinds of nonsense on racial theory.