Category: ethics
Associated thinker(s): Derek Parfit, Gregory Kavka
Original publication or approximate period: Modern formulations in population-ethics work of the 1970s–1980s; Reasons and Persons (1984)
Difficulty: Advanced
Themes: future generations, harm, identity
Related experiments: repugnant-conclusion, fission
Kind: thought experiment
Research checked: 2026-10-30
A policy chosen today changes future living conditions and also changes who meets whom and when children are conceived. Under one policy, future people have difficult but worthwhile lives. Under another, different people enjoy better lives. A person born under the first policy cannot simply say that the second policy would have given them a better life: on the stipulated facts, they would never have existed.
Can a choice be wrong even if it makes no particular person worse off than that person otherwise would have been?
The case challenges a simple connection between wrongdoing and comparative harm. It matters for environmental policy and reproductive ethics, where choices can change identities as well as welfare. Those applications require more facts than the stripped-down example supplies.
Track the alternatives using names rather than a generic phrase such as “future children.” In one branch, person A exists with a worthwhile but difficult life. In the other, A never exists and person B has a better life. Saying that the second branch improves A’s life misdescribes the stipulated comparison. Once that mistake is removed, a moral assessment is still needed. The exercise forces a choice about what grounds the criticism: a comparative harm to someone, a noncomparative standard, a violated right, or the impersonal quality of the outcome.
Impersonal accounts can compare the quality of outcomes without requiring one individual to be worse off. Person-affecting responses may revise the idea of harm, appeal to rights or standards, or distinguish reasons to create better lives from claims made by particular individuals. Each approach faces further puzzles.
The problem does not show that future suffering is harmless or acceptable. It presupposes lives worth living; cases of lives worse than nonexistence raise additional questions. Nor does a change in conception timing mechanically guarantee the broad policy conclusion without an argument about identity.
Parfit’s depletion cases and Kavka’s slave-child case place the problem in different settings. The repugnant conclusion arises when an attempted solution compares populations by simply adding up welfare.
Historical association: Modern formulations in population-ethics work of the 1970s–1980s; Reasons and Persons (1984). The sources above support the scenario and its intellectual context. Where an original work was not retrieved in full, its account is mediated by the named academic reference; no claim of full primary-source verification is made. The explanation and reflection questions here are original editorial prose.