Mathematics is a language plus reasoning. It's like a language plus logic. Mathematics is a tool for reasoning.

What Do You Care What Other People Think?

All mass is interaction.

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.

There are thousands of years in the past, and there is an unknown amount of time in the future. There are all kinds of opportunities, and there are all kinds of dangers.

In those days, in Far Rockaway, there was a youth center for Jewish kids at the temple.... Somebody nominated me for president of the youth center. The elders began getting nervous, because I was an avowed atheist by that time.... I thought nature itself was so interesting that I didn't want it distorted like that. And so I gradually came to disbelieve the whole religion.

Once we were driving in the midwest and we pulled into a McDonald's. Someone came up to me and asked me why I have Feynman diagrams all over my van. I replied, "Because I am Feynman!" The young man went, "Ahhhhh!"