Brian Cox

Do you know what?

It's enough fun to not worry too much about the outcome.

You started with a story about a monkey in a tyre at the zoo by itself, which suggests that it is fun.

Is that the tyre element of it?

And in terms of things like, you know, sometimes you'll see these kind of evangelical preachers, televangelists or whatever going on about the fact that we don't see homosexuality in any other animal, which means they've never even owned a dog, to be honest.

So again, in terms of same-sex relations, sexual relations in the monkey world.

But I think that's in some ways why it's good to know is you go, this is not, you know, people will describe certain things as being against nature when in fact you go, let us look at the natural world and we see.

Dave, I suppose the big question for you really is, and we need a definition, what is love?

It's committing to not kissing your wife until you're married.

I don't... Who knows?

Who knows what love is?

And even in our own lives, most of us believe we're in love and later can reassess that and go, that wasn't it, actually.

Because until you've experienced it... So teenagers fall in love, but it's not.

It's a kind of infatuation.

And later in life, when you feel more deeply in love, you are able to look back on that and go, I just really liked her.

It's not the same, is it?

And what I was feeling was an excitement for novelty.

But it's, how do you possibly define what it is until it's too late?

What you've described there eloquently is how complex these ideas are.

We are getting quite close to the end.