# Derek Parfit Influential Oxford moral philosopher whose work on personal identity, future generations, and population ethics (*Reasons and Persons*, 1984) became a foundation of longtermism and effective altruism — the intellectual current cited in tech-right-adjacent texts like [[Tyler Cowen]]'s [[Stubborn Attachments]]. His "non-identity problem" and concern for the far future underpin much EA/longtermist reasoning. *Stub — expand with: personal-identity arguments, population ethics and the Repugnant Conclusion, influence on EA/longtermism.*