I don't think I buy that the idea of "total amount of suffering" makes sense. That suggests that a world with more people, who are each suffering less, would be a worse world overall by virtue of having more "total" suffering. That strikes me as strongly counterintuitive, and very hard to justify rationally, though I'd be happy to see the attempt.

And in fact that seems to be the world we're living in. For example, in this TED talk[1] Steven Pinker makes the argument a person being born today — anywhere in the world, counting Iraq and Darfur — has less of a chance of dying at the hands of another person than at any time before in history.

So I'm a little skeptical of the idea that the only way to make the human race feel better is to have less of it.

[1] http://www.ted.com/talks/steven_pinker_on_the_myth_of_violen...