Better Never to Have Been. At first only the intelligentsia come to believe in ZP (zero population), as they call it. (ZPG--zero population growth--is seen as old-fashioned.) Only the "lower classes" go on having children, until the high and mighty manage to simplify and disseminate the message that existence is a harm. Populations dwindle, children become more rare. Then, with practically every woman alive over child-bearing age, a very simple problem is found with Benatar's argument. Is there time for procreation to start up again? I think this will be very exciting, and I do want Sigourney Weaver to star in the movie version. Let's have her be the one who discovers the error and attempts to get pregnant at an advanced age
The book/movie will be exciting and thought-provoking. How much should we trust those brainy ethicists whose arguments normal people can barely understand? How much should we trust our gut feelings? That's the "meta" question Benatar's book raises for me.
But what about "the error" Signourney will discover? More work needed... But here's what I'm thinking about. The pivotal claim in Benatar's argument has to do with an asymmetry. Absent pain is good, even if no one's experiencing the absence. Absent pleasure isn't bad; it would take someone missing it for it to be bad. (I summarize the rest of the argument here.) You can test out your intuitions about this by thinking about an empty place, say Mars, or an empty island. It will be prejudicial if you imagine dangerously high populations nearby, so don't make the island right off Mumbai, and you may want to picture Mars in a lonelier universe than ours.
Anyhow, Benatar points out that nobody mourns the absent pleasure on Mars. Right. But nobody feels glad about the absent pain, either. As he notes, "most people do not even think about the absent lives on Mars." (p. 35) But let's force ourselves to contemplate these two absences. At the dinner table a few nights ago, I said, "assign a number (positive, negative, or 0) to the absent pleasure and the absent pain on Mars." They said "Oh God, do we have to?" Then one person (over the age of 13) gave a zero both to the absent pleasure and the absent pain. Two (both age 13) gave -3 to absent pleasure and +3 to absent pain. There was no asymmetry intuition. (I'll have a bigger sample in the fall, when I teach Benatar's argument. I wonder if any X-phi folks have studied this.)
The more I think about it, the more I think zero has to be the right number for the absent pain on Mars--a positive number won't do. This is clear when you consider that it's impossible to pick a number. Are all pains absent from Mars? Or all possible pains absent? Mars is certainly better than Earth, painwise, but that's fully represented by giving Earth a large negative number for pain and Mars a zero for pain's absence. From my informants' standpoint, it's also OK to say (symetrically) that Earth is better than Mars, pleasurewise. There the score is a large positive number to zero.
If no asymmetry, then no call for extinction. This is what Sigourney is going to argue, at the 11th hour.