Editing Derek Parfit (section)

=== Non-identity problem ===
The [[non-identity problem]] arises from the observation that actions taken today can fundamentally alter which future people come into existence. In chapter 16 of ''Reasons and Persons'', Parfit posits that one's existence is intimately related to the time and conditions of one's conception.<ref name=":4" />{{Rp|351}} He calls this "The Time-Dependence Claim": "If any particular person had not been conceived when he was in fact conceived, it is in fact true that he would never have existed".<ref name=":4" />{{Rp|351}} Like the [[butterfly effect]] in [[chaos theory]], small changes in initial conditions can have profound downstream effects on human reproduction. Actions may not just affect the welfare of future individuals, but also cause different individuals to be born.<ref>{{Cite web |title=The Nonidentity Problem |url=https://plato.stanford.edu/entries/nonidentity-problem/ |website=Stanford Encyclopedia of Philosophy}}</ref> If the moral ramifications of potential policies are considered in [[Person-affecting view|person-affecting]] terms, there is no reason to prefer a sound policy over an unsound one, provided that its effects are not felt by the next few generations.<ref>{{Cite web |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}}</ref>

Parfit eventually became convinced that personal identity is irrelevant to ethics.<ref name=":6">{{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}}</ref> He wrote about an article in ''[[The Times]]'' in which a politician praised a recent decline in teenage pregnancy. A man wrote a letter saying he had had a teenage mother and, although the early years had been hard, he now had a life thoroughly worth living. The man asked whether the politician was suggesting it would have been better if he had never been born. Parfit said the man would waive the right to have such-and-such level of a good start in life merely to exist. He wrote, "The objection must be that if she had waited, she could have given to some other child a better start in life."<ref>[https://rintintin.colorado.edu/~vancecd/phil308/Parfit1.pdf “The Non-Identity Problem,”] from the book ''Reasons and Persons'', Derek Parfit, please see page 11 in this excerpt.</ref>