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slang.fyi

longtermism

/ˈlɒŋ.tɜːm.ɪ.z(ə)m/

Rare

The belief that the long-term future of humanity matters so much that it should dominate our moral priorities today.

Controversial. Critics argue it justifies ignoring immediate suffering in favor of speculative future populations. Often invoked in AI safety debates and sometimes used to criticize EA-adjacent reasoning.

Real-world examples4 examples
#ExampleWhat it meansSource
01The longtermism crowd really believes preventing AI risk is more important than every current humanitarian crisis combined.Summarizing the extreme version of the longtermist argument.reddit, 2024
02I keep running into longtermism and I still cannot decide if it is genius or completely detached from reality.Expressing genuine uncertainty about whether the philosophy is compelling or absurd.x, 2023
03Longtermism is just a way for rich tech people to feel good about ignoring poverty.A critical take framing longtermism as a justification for self-interest.x, 2023
04Once you actually do the math on longtermism it becomes hard to argue against. The numbers are wild.Someone acknowledging the internal logic of the framework is hard to refute once you accept its premises.reddit, 2022

Use it when

  • Discussing the philosophy that future generations should have enormous weight in moral calculations.
  • Referencing the ideological foundation behind much AI safety and existential risk work.
  • Critiquing reasoning that dismisses current harms in favor of abstract future benefits.

Do not use it when

  • Someone just cares about long-term environmental sustainability.
  • Someone thinks ahead in their personal financial planning.

Longtermism vs effective altruism

longtermism

Longtermism specifically argues that the far future should dominate our moral priorities due to sheer scale.

VS

effective-altruism

Effective altruism is the broader framework; longtermism is one branch within it.

Origin and context

Developed as a formal philosophical position by Oxford philosophers including William MacAskill and Toby Ord. Gained mainstream attention through MacAskill's 2022 book 'What We Owe the Future'.

First seen
2010s
Confidence
high

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https://slang.fyi/longtermism
Updated: 2026-08-28License: CC BY 4.0

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