William MacAskill is a Scottish philosopher associated with the University of Oxford and one of the figures most identified with the development of Effective Altruism and Longtermism. He co-founded the Oxford-based organizations Giving What We Can and the Centre for Effective Altruism, helped establish the charity-evaluation and research infrastructure around the movement, and authored Doing Good Better (2015) and What We Owe the Future (2022), the latter a book-length argument for longtermism (Source: https://www.williammacaskill.com/).
| Field | Value |
|---|---|
| Role | Philosopher; movement organizer |
| Affiliation | University of Oxford; Centre for Effective Altruism; Forethought |
| Known for | Co-founding effective altruism; advancing longtermism |
| Principal works | Doing Good Better (2015); What We Owe the Future (2022) |
Positions and arguments
MacAskill is a central proponent of the view that present decisions should give substantial weight to their effects on the long-term future, including future generations and the reduction of existential risk. What We Owe the Future develops the case that, because the number of people who could exist in the future vastly exceeds the present population, improving humanity's long-run trajectory is among the most important things present actors can do (Source: https://www.williammacaskill.com/). This framing recurs in AI policy debates over how to weigh near-term harms against speculative long-term and catastrophic risks, a tension covered on Longtermism and AI Existential Risk.
MacAskill has also written on the relationship between effective altruism and the more recently distinct AI safety community. In an essay on effective altruism "in the age of AGI," he noted that some observers view effective altruism as a legacy movement likely to fade as a dedicated AI safety movement grows, while arguing for the movement's continued relevance as advanced AI develops (Source: https://willmacaskill.substack.com/p/effective-altruism-in-the-age-of). His association with the movement also draws scrutiny because of his earlier public connection to Sam Bankman-Fried and the FTX Future Fund, whose collapse in 2022 prompted reassessment within effective altruism of its funding structure and governance (Source: https://en.wikipedia.org/wiki/Effective_altruism).
Relationships
- related: Effective Altruism, Longtermism — movement and framework he helped develop.
- related: Toby Ord, Nick Bostrom — fellow figures associated with the Oxford longtermist lineage and the Future of Humanity Institute.
Provenance note
Page created 2026-06-15 (gap-scan) from supporting web sources (MacAskill's own site, his Substack essay, and reference material). It resolves a dangling [[entities/will-macaskill]] reference relied on by Effective Altruism and Longtermism. A foundational ingest of MacAskill's own writing (e.g., What We Owe the Future or the "EA in the age of AGI" essay) would deepen this page and the two concept pages.