Nonidentity problem

{{short description|Concept in population ethics}}

{{use dmy dates|date=May 2024}}

The nonidentity problem (also called the paradox of future individuals{{cite journal |last=Kavka |first=Gregory |date=1982 |title=The Paradox of Future Individuals |url=http://faculty.smu.edu/jkazez/pap/kavka.pdf |journal=Philosophy and Public Affairs}}) is a problem in population ethics concerning actions that affect the existence, identity, or well-being of future people. It arises from the observation that even small changes can alter the timing and circumstances of child conception, leading to entirely different individuals coming into existence, similarly to the butterfly effect in chaos theory. Actions affecting future generations will thus not simply affect the welfare of individuals, but rather cause different individuals to come into existence. The problem was described and explored by Derek Parfit in his 1987 book Reasons and Persons.{{Cite web |last=Wilkinson |first=Dominic |last2=Doolabh |first2=Keyur |date=2017-06-12 |title=Should we take ethical account of people who do not yet exist? |url=https://aeon.co/essays/should-we-take-ethical-account-of-people-who-do-not-yet-exist |access-date=2025-01-26 |website=Aeon |language=en}} It is a challenge to person-affecting views, which are based on the intuition that "what is bad must be bad for someone".{{cite encyclopedia |title=The Nonidentity Problem |encyclopedia=The Stanford Encyclopedia of Philosophy |url=http://plato.stanford.edu/entries/nonidentity-problem |access-date=2015-12-17 |last=Roberts |first=M. A.}}

An example proposed by Parfit involves thinking of two policies: "conservation" and "depletion". In the depletion strategy, current generations have a slightly higher quality of life, but unchecked use of natural resources eventually leads to depletion, significantly degrading the welfare of future generations. Parfit argues that person-affecting views would favor the depletion policy because it benefits current generations of identifiable people, even though the conservation policy is generally considered ethically superior. He eventually became convinced that personal identity is irrelevant to ethics.{{Cite web |last=Matthews |first=Dylan |date=2017-01-03 |title=The whole philosophy community is mourning Derek Parfit. Here’s why he mattered. |url=https://www.vox.com/science-and-health/2017/1/3/14148208/derek-parfit-rip-obit |access-date=2025-01-26 |website=Vox |language=en-US}}

A solution to the problem is to adopt impersonal views, theories that don't rely on the notion of personal identity, such as utilitarianism. But impersonal views lead to what Parfit calls the "repugnant conclusion", the idea that for any possible population with very high quality of life, there could be a much larger imaginable population whose existence would be better, even though its members have lives that are barely worth living. Some philosophers consider, however, that almost all credible theories of population ethics imply some form of the repugnant conclusion anyway.{{Cite journal |last=Zuber |first=Stéphane |last2=Venkatesh |first2=Nikhil |last3=Tännsjö |first3=Torbjörn |last4=Tarsney |first4=Christian |last5=Stefánsson |first5=H. Orri |last6=Steele |first6=Katie |last7=Spears |first7=Dean |last8=Sebo |first8=Jeff |last9=Pivato |first9=Marcus |last10=Ord |first10=Toby |last11=Ng |first11=Yew-Kwang |last12=Masny |first12=Michal |last13=MacAskill |first13=William |last14=Lawson |first14=Nicholas |last15=Kuruc |first15=Kevin |date=2021-04-13 |title=What Should We Agree on about the Repugnant Conclusion? |url=https://www.cambridge.org/core/product/identifier/S095382082100011X/type/journal_article |journal=Utilitas |language=en |volume=33 |issue=4 |pages=379–383 |doi=10.1017/S095382082100011X |issn=0953-8208|hdl=10852/90849 |hdl-access=free }}