Steven Pinker

Well, because everyone else stays home on Sunday.

So that's a good reason for me to do it if everyone else is doing it.

So a lot of our society depends on common knowledge.

This immediately raises a question.

People say, well, you define common knowledge as I know that she knows that I know that she knows that I know that she knows, but no one can keep track of them.

That's why you have plots like the Honeymooners or there's an episode in Friends that people always tell me about where Rachel says, Joey, they don't know that we know that they know that we know.

You can't say anything.

And he says, I couldn't even if I wanted to.

The point being that your head starts to spin when you have to keep track of more than two or three layers of I know that she knows.

So how is this possible?

Well, the reason it's possible is that we can get common knowledge at a stroke when there is something that we sense to be public or out there or salient or you can't miss it or it's in your face.

So if I see something at the same time as I see you see it, then that implicitly packs into it as many layers as we would ever need, and we don't have to think them all through.

But it also means that we're really, really sensitive to something that is public, that you can't ignore, versus something that may be known privately.

And I have chapters in the book on how that shapes our language, why we don't just blurt out what we mean, but often...

veil our intentions in euphemism and innuendo to prevent things from being common knowledge phenomena like being in the closet or for any whatever is the reason well and it used to be it used to be the that's where my clothes are that's why well my graduate that means you have a walk-in closet i didn't know that very good dude

Well, my graduate advisor, actually, he insisted he was not gay.

He was a homosexual.

In the day.

He said that to be gay, you have to be born in the 50s or later.

He was born in the 20s.