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.

I happen to know this, and I happen to know that, and maybe I know that;and I work everything out from there. Tomorrow I may forgot that this is true, but remember that something else is true, so I can reconstruct it all again. I am never quite sure of where I am supposed to begin or where I am supposed to end. I just remember enough all the time so that as the memory fades and some of the pieces fall out I can put the thing back together again every day

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

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

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

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

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

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

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