On December 4, 2013, I introduced and framed the Intelligence Squared U.S. debate on veganism.  The process of raising and slaughtering animals is one that I think most of us prefer not to think about very much, and we’re forced to think about it in this debate.

I have come to realize that at least many people on the pro side of this motion, “Don’t Eat Anything Wtih A Face,” this is not simply about a dietary choice. This is a kind of defining expression of who they are.  There are health issues, which both sides will have evidence to marshal on why their preferred diet is in fact better for health. There are environmental considerations. There are ethical considerations about the way animals are treated in this process. There’s aesthetic considerations, even if you don’t — they don’t quite rise to a level of ethics.

John Donvan: So, you know, as a rule, I’m looking back at this season, and we do a lot of debates that are sort of very, very up in the — up in the ether. We’ve done the policies on drones, we’ve done international labor markets. And today we’re kind of going in the opposite direction and digging down deep inside the human digestive system. And I kind of want to get a sense of what — what’s lighting up this debate for us?

Robert Rosenkranz: Well, we did a debate a couple of years ago on the resolution, “Organic Food is Marketing Hype.” And if you will recall, you and I were really surprised that it created so much emotional intensity among the panelists, more than any of the other 80 debates that we’ve done. And I at last came to realize that at least for the people — many people on the pro side of this motion, this is not simply about a dietary choice. This is a kind of a — almost a defining expression of who they are as people. It’s — it has an ethical content, an aesthetic content, a kind of political content. It’s really about the identity of people who believe passionately in this. And that’s why that debate was so successful, and that’s why I think this is going to be a very interesting evening.

John Donvan: Have you seen what’s happening on our website already?

Robert Rosenkranz: Oh, my god. It is totally crazy.

John Donvan: Yeah, I mean, you can all still go and join afterwards, but there already is a very, very lively debate among civilians taking place on our website. But beyond a sort of a broad statement of values, are there really separate lines of attacks, sort of empirical attack that these debaters can make?

Robert Rosenkranz: Yes. I mean, there definitely are. There are health issues, obviously, with — both sides will have evidence to marshal on why their preferred diet is in fact better for health. There are environmental considerations. There are ethical considerations about the way animals are treated in this process. There’s aesthetic considerations, even if you don’t — they don’t quite rise to a level of ethics. I think the whole process of raising and slaughtering animals is one that I think most of us prefer not to think about very much, and we’re going to be forced to think about it tonight.

John Donvan: And what we have tonight are four debaters, Bob, who have life stories that actually interact with this subject in real and vital ways.

Robert Rosenkranz: And I have to tell you, I saw them in the green room, and all four of them look very healthy.

John Donvan: It was very annoying.Let’s welcome our debaters to the stage. And thanks to Bob Rosenkranz.

Watch the full debate and learn more from Intelligence Squared U.S.