The Non-Identity Problem

Ordinary ethics rests on a simple foundation: an act is wrong if it makes someone worse off than they would otherwise have been. The non-identity problem is Derek Parfit’s proof that this foundation collapses when applied to large-scale choices about the future. Consider two policies—Depletion and Conservation—that produce not merely different outcomes for the same future people but different future people entirely: different conceptions, different births, different individuals whose very existence depends on which policy was chosen. The people who live in the depleted world cannot say they were harmed by the choice, because the only alternative for them was never to exist; and a life that is difficult but worth living is not worse than non-existence by any standard the person inside can apply. The ordinary harm-based argument evaporates. The intuition that something deeply wrong was done survives. The gap between the intuition and the framework is the non-identity problem, and it is the