Hello, it's Chris Anderson here, the guy who gets to run TED.

Now, you're tuning into a special archive presentation of TED Talks Daily.

This one features one of my favorite all-time TED speakers from back in 2005, David Deutsch.

If you like the talk as much as I do, I'd urge you to subscribe to our new podcast, The TED Interview,

because we've posted an episode featuring David Deutsch, and in it I get to dive into

his thinking about knowledge, its role in the cosmos, and the fact that humans might not be

quite as insignificant as we sometimes think we are.

Please join me for the TED interview wherever you listen.

We've been told to go out on a limb and say something surprising.

So I'll try and do that, but I want to start with two things that everyone already knows.

And the first one, in fact, is something that has been known for most of recorded history.

And that is that the planet Earth or the solar system or our environment or whatever

is uniquely suited to sustain our evolution,

or creation as it used to be thought,

and our present existence, and most important, our future survival.

And nowadays this idea has a dramatic name, Spaceship Earth.

And the idea there is that outside the spaceship, the universe is implacably hostile,

and inside is all we have, all we depend on, and we only get the one chance.

If we mess up our spaceship, we've got nowhere else to go.

Now, the second thing that everyone already knows is that,

contrary to what was believed for most of human history,

human beings are not in fact the hub of existence.

...