This is an ABC podcast.

I'm looking out at a beautiful seascape.

The sky is a dazzling light blue.

The aquamarine ocean is flicked with bright white waves

and glistening yellow reflections of the sun.

And nearby there are bottlebrush trees covered in rich red flowers.

If you were standing next to me, can I be sure that you're experiencing the same thing as me?

The answer is no.

What you're referring to is the idea of experience being private.

Let's say two people are looking at some scene or something, and they're describing it to each

other, and it seems like they're experiencing the same thing.

Well, it turns out that we know that they perhaps are experiencing

maybe about the same thing, but we have no way of knowing exactly what they are experiencing.

There's a term that philosophers use called qualia. Qualia is the essence of an experience.

So if you're having a red qualia, then that is the essence of what redness is to you. Let me give you an example to illustrate this idea of the private mind. Let's say that there's two people standing on the edge of the Grand Canyon. They're looking out and they're marveling at how wonderful it looks and

they're pointing out things to each other and it seems like they're getting about the same

experience. All of a sudden, something called the experience fairy comes along, just bear with me

on this, and taps them on their shoulder and all of a sudden their experiences switch.

So now you're having the experience of your friend and your friend is having your experience. And amazingly enough, they're not exactly the same.

The reds look a little redder perhaps than they did when you were looking at it.

The far end of the canyon looks a little further away.

There are subtle differences. That's what we mean by

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