Benatar explains the pain/pleasure asymmetry in depth in Chapter 2 of the book, and those who feel they have a slam-dunk logical objection to the asymmetry might be advised to read the detailed treatment of the asymmetry in the chapter before assuming Professor Benatar just missed the objection. Ultimately, though, there remain real, non-trivial objections to the asymmetry, because the asymmetry is built using the common ethical philosophy tool of explaining and analyzing commonly held intuition. Since the asymmetry is ultimately based on intuition, it may be disputed by those who, in good faith, do not share the intuitions upon which it is built.
Many, however, deny the asymmetry without fully grasping the consequences of the asymmetry. I wish to map out some ethical problems that those who deny the asymmetry must explain in a manner consistent with rejecting the asymmetry.
1. The Austrian Basement
E. F. has been kidnapped by her father and imprisoned in an Austrian cellar since her early adolescence. Her father repeatedly rapes her over the course of several years. E. F. gives birth to several children sired by her father. She reasonably believes that all these children have severe health problems, and that at least the female children will likely be abused by her father as they grow up.
In Year 10 of her imprisonment, with four children born and removed from her by her father, she discovers a box (unknown to her father) hidden under a floorboard in her cell, containing everything she needs in order to practice undetectable birth control.
a. Does she have a duty to practice birth control and avoid having more babies? Does she have a duty not to practice birth control, because she would be depriving her unborn babies of life (which, while it would have certain problems, would nevertheless presumably be worth living)? (Assume she would like the company of more babies, but fears the pain of more unassisted childbirth, and the "interests of the unborn children" is the concern that will break the tie, given her personal ambivalence.)
c. (Only for those who think that antinatalism requires suicide.) If you answered that the daughter has a duty to practice birth control, is that the same as saying that the real-life E. F.'s seven children have worthless lives and should be put to death?
Of course, I'm making up the part about the birth control choice, but here's an excerpt from the real life story:
The dungeon in which they lived was so small that the older ones had to watch as his father delivered his daughter’s subsequent children. Presumably they also had to watch as he had intercourse with his daughter to beget them – she claims that he repeatedly raped her – and regularly beat her. The dungeon contained one padded room, its walls and floor covered in rubber, the purpose of which is still unclear.
2. Slum World
The Supreme World Leaders meet in Tokyo in 2100 and decide that the world has a choice. Either the 2100 world population of 3 billion can be maintained in relative splendor, with fresh kumquats and sensory implants for everyone, or the world population can be increased to 100 billion, with everyone living in conditions similar to the conditions of a 20th century slum, apparently endured by upwards of 900 million people circa the year 2000.
a. Which condition should the Supreme World Leaders choose?
c. If you answered that Low Population Splendor World is preferable to Slum World, what about the interests of the unborn people who would have come into existence had Slum World been selected? Aren't they being harmed by not being brought into existence? What right to the inhabitants of Low Population Splendor World have to deny the extra 97 billion people a right to exist, just for the sake of the happiness of 3 billion?