Episode Summary
Executive Summary: Rob Wiblin interviews philosopher Will MacAskill about the origins of effective altruism, moral uncertainty, and what those ideas imply for action. MacAskill defends expected-value-style reasoning under moral uncertainty, argues for taking utilitarianism more seriously than common sense does, and says EA should emphasize long-term future risks, animal welfare, and moral reflection while avoiding sloppy or overly contrarian messaging.
Main Topics: Origins and growth of effective altruism: MacAskill traces EA to the convergence of GiveWell, Giving What We Can, and 80,000 Hours, and describes its growth from a small philosopher-led project into a global community focused on doing the most good. Moral uncertainty and decision theory: The conversation’s core theoretical focus: how to act when unsure which moral theory is true. MacAskill argues for treating moral uncertainty analogously to empirical uncertainty using expected-value reasoning, while noting major complications such as comparability, fanaticism, and infinite values. Structuralism, amplified theories, and comparison across moral views: MacAskill explains why simple normalization approaches to comparing moral theories may fail, and defends the possibility that theories can differ in more than rank order, including in 'right makers' and strength of value. Arguments for classical utilitarianism: He presents several arguments for utilitarianism, including historical track record, Harsanyi’s veil-of-ignorance reasoning, and Parfit-style rejection of personal identity as morally fundamental. Practical implications for EA: MacAskill says moral uncertainty supports a broad 'consequentialism plus rights' stance, strong concern for the long-term future, animals, and moral option value, plus caution about irreversible actions. Academic life and incentives: He discusses downsides of being a professor: bureaucracy, teaching load, publication delays, and distorted incentives in academia, while arguing philosophy still matters enormously for high-level moral questions. EA culture, messaging, and diversity: MacAskill says EA should become more welcoming, more epistemically and demographically diverse, and less prone to aggressive or oversimplified messaging, especially around earning to give and existential risk.
Key Arguments: Decision-making under moral uncertainty should mirror decision-making under empirical uncertainty: assign probabilities to moral views and evaluate actions by their expected choiceworthiness. Simple structuralist normalizations may be inadequate because moral theories can differ in cardinal structure, right-makers, and the strength—not just the ranking—of moral reasons. Fanaticism, incomparability, and infinite-value theories create serious problems for standard expected-value aggregation, suggesting the issue is more complex than straightforward arithmetic. MacAskill’s practical takeaway is a hybrid view: respect side constraints/rights while also trying to maximize good where doing so is permissible. Long-term future and moral reflection matter enormously because the stakes of humanity’s future are so large and because moral history shows many past certainties were disastrously wrong. Utilitarianism has a strong historical track record: Bentham and Mill supported progressive causes well ahead of their time, whereas Kant held many now-abhorred views. Harsanyi’s veil-of-ignorance argument, if set up with equal probability of being anyone, points toward utilitarianism rather than Rawlsian maximin. Parfit-style arguments about fission and psychological continuity weaken the idea that personal identity is morally fundamental, supporting utilitarian-style trade-offs across persons. EA should not be framed narrowly as earning-to-give or RCT-only charity; current core thinking is broader, more long-termist, and more open to direct work and policy. Philosophical disagreement is real but often overstated; surveys and practical judgments show more convergence than the public expects, especially on animal welfare and some utilitarian intuitions.
Data Points: EA local groups: about 100 - MacAskill says effective altruism spread to around 100 local groups worldwide. CEA CEO tenure: about 1.5 years - He says he returned as CEO of the Center for Effective Altruism about a year and a half earlier and stepped down recently. Book timeline: 1 to 1.5 years - He estimates the moral uncertainty book will likely come out in roughly a year to a year and a half. Philosopher survey split: roughly one-third each - He describes a survey with about a third consequentialists, a third deontologists, and a third virtue ethicists/others. Philosophy community view on meat: two-thirds - He says about two-thirds of philosophers believe it is obligatory not to eat meat. Oxford admissions algorithm weighting: 8 to 1 - He says Oxford’s data suggested test scores should be weighted about eight times more than interviews. Publication delay: 5 years - He cites one major publication that took five years from submission to publication. Age of youngest associate professor: 28 - Biographical detail: he became the youngest associate professor of philosophy in the world at age 28. EA conference growth: thousands of people - He describes EA as a vibrant global community of thousands. Podcast output in 2018: 37 episodes / 73 hours - Outro note from the host about the show’s 2018 output.
Pivotal Quotes: "if we really do want to take moral uncertainty into account, how should we do that?" — Rob Wiblin: Introduces the central philosophical question of the interview. "we should do something like expected value reasoning" — Will MacAskill: Summarizing his preferred framework for acting under moral uncertainty. "I think the biggest own goal in the history of moral philosophy" — Will MacAskill: His criticism of Rawls’s version of the veil-of-ignorance argument.
Implications: Listeners get a roadmap for thinking about ethics with uncertainty: update by expected value, stay humble about moral conclusions, prioritize long-term and irreversible risks, and avoid simplistic EA stereotypes. The episode also suggests philosophy has direct practical implications for careers and global priorities.