longtermism
In plain wordsThe belief that we should care a great deal about how things go for humanity thousands or millions of years from now, since far more people may live then than have ever lived.
The ethical position that shaping the far future well is one of the most important things people alive today can do. William MacAskill, a leading proponent, rests it on three claims: future people count morally, they could vastly outnumber everyone who has lived so far, and what we do now can change how their lives go. Strong longtermism holds that, in many decisions, effects on the far future are the most important consideration. Longtermists typically prioritize reducing existential riskexistential risk, n.: A danger that could end humanity, or shut it out of a good future forever. Some experts count advanced AI among the largest such risks; others think this worry is overblown., including risks from misaligned AI, engineered pandemics and nuclear war, and avoiding bad value lock-invalue lock-in, n.: The possibility that powerful AI could freeze one set of values or one power structure in place for an extremely long time, so that later generations could never change course., arguing that preventing extinction preserves an astronomically large future. The view has shaped AI-safety funding and research through effective altruismeffective altruism, n.: A movement that treats charity like a research problem, comparing causes by how much good each dollar or working hour achieves; many of its members came to rank risks from advanced AI as a top priority.. Critics object to its reliance on expected-value reasoning about tiny probabilities of vast payoffs (see Pascal's muggingPascal's mugging, n.: A puzzle about decisions: if someone promises an astronomically huge reward or threatens a huge disaster, even a tiny chance they are honest seems to justify paying them, which looks absurd.), to its potential to discount present suffering, and to its association with wealthy donors and AI companies; some fold it into the critical acronym TESCREALTESCREAL, abbr.: A critical label for a cluster of related belief systems, including transhumanism, effective altruism and longtermism, that its coiners say drive the push to build AGI and share roots with eugenics..
You don't need longtermism to care about AI risk if you think it could arrive within a decade.
Origin
Coined around 2017 by the Oxford philosophers William MacAskill and Toby Ord; Hilary Greaves and MacAskill's paper 'The Case for Strong Longtermism' (2019, revised 2021) and MacAskill's What We Owe the Future (2022) gave its standard formulations. Nick Bostrom's 2003 paper 'Astronomical Waste' is a key precursor.
Related
- effective altruismeffective altruism, n.: A movement that treats charity like a research problem, comparing causes by how much good each dollar or working hour achieves; many of its members came to rank risks from advanced AI as a top priority.
- existential riskexistential risk, n.: A danger that could end humanity, or shut it out of a good future forever. Some experts count advanced AI among the largest such risks; others think this worry is overblown.
- value lock-invalue lock-in, n.: The possibility that powerful AI could freeze one set of values or one power structure in place for an extremely long time, so that later generations could never change course.
- Pascal's muggingPascal's mugging, n.: A puzzle about decisions: if someone promises an astronomically huge reward or threatens a huge disaster, even a tiny chance they are honest seems to justify paying them, which looks absurd.
- suffering risksuffering risk, n.: A risk that the future contains suffering on a vast scale, far beyond anything in history, for example if powerful AI created enormous numbers of suffering beings.
- TESCREALTESCREAL, abbr.: A critical label for a cluster of related belief systems, including transhumanism, effective altruism and longtermism, that its coiners say drive the push to build AGI and share roots with eugenics.
Sources
- Greaves, H. & MacAskill, W. (2021). The Case for Strong Longtermism. Global Priorities Institute Working Paper 5-2021.
- MacAskill, W. (2022). What We Owe the Future. Basic Books.
Mentioned in
existential riskexistential risk, n.: A danger that could end humanity, or shut it out of a good future forever. Some experts count advanced AI among the largest such risks; others think this worry is overblown., effective altruismeffective altruism, n.: A movement that treats charity like a research problem, comparing causes by how much good each dollar or working hour achieves; many of its members came to rank risks from advanced AI as a top priority., Distributed AI Research InstituteDistributed AI Research Institute, prop. n.: Timnit Gebru set up this institute in 2021, a year after her departure from Google, to research the damage AI can do, especially to marginalized communities, without relying on big-tech money., ForethoughtForethought, prop. n.: A small Oxford research nonprofit that asks what problems, besides keeping AI safe, the rapid arrival of superintelligent AI would create, from power grabs to the rights of digital minds., Future of Humanity InstituteFuture of Humanity Institute, prop. n.: Nick Bostrom's research center at Oxford University (2005–2024), where philosophers and scientists studied threats that could permanently derail humanity's future, advanced artificial intelligence among them., Open PhilanthropyOpen Philanthropy, prop. n.: A large American charitable foundation, renamed Coefficient Giving in 2025, that has been the biggest private funder of research on the risks of advanced AI., Pascal's muggingPascal's mugging, n.: A puzzle about decisions: if someone promises an astronomically huge reward or threatens a huge disaster, even a tiny chance they are honest seems to justify paying them, which looks absurd., suffering risksuffering risk, n.: A risk that the future contains suffering on a vast scale, far beyond anything in history, for example if powerful AI created enormous numbers of suffering beings., TESCREALTESCREAL, abbr.: A critical label for a cluster of related belief systems, including transhumanism, effective altruism and longtermism, that its coiners say drive the push to build AGI and share roots with eugenics., Toby OrdToby Ord, prop. n.: An Australian philosopher at Oxford who helped found effective altruism and estimated, in his book 'The Precipice', that unaligned AI is the largest threat to humanity's future this century., transhumanismtranshumanism, n.: A movement holding that people should use technology, such as genetic engineering, brain implants or AI, to overcome human limits like aging, disease and death, and become more than human., value lock-invalue lock-in, n.: The possibility that powerful AI could freeze one set of values or one power structure in place for an extremely long time, so that later generations could never change course.