Peter Singer on Utilitarianism, Influence, and Controversial Ideas
Peter Singer — Professor of Bioethics at Princeton and author of the revised Animal Liberation Now — joins Tyler Cowen for Ep. 181 to defend utilitarianism as a living, practised ethics, examine its limits under radical thought experiments, and reflect on the state of Effective Altruism, academic philosophy, and the decades-long failure to end factory farming.
Key ideas
- Reason can override evolved instinct, but only partially and unevenly. Singer remains fully Darwinian — he accepts that humans evolved to eat animals, kill painfully, and privilege kin — but insists that reason, itself a product of evolution, can lead us to conclusions our instincts would never reach. The open question is not whether this is possible but how far it can spread before the limits of selective rationality reassert themselves.
- Factory farming is the clearest case of indefensible harm. Where big-picture utilitarian calculations (colonising continents, total population size) become intractable, Singer holds that factory farming is not: the suffering caused to billions of sentient creatures exceeds any plausible human benefit, and the case does not require fine-grained inter-species welfare comparisons to hold.
- Effective Altruism has drifted too far from the present. Singer expresses concern that the movement’s gravitational centre has shifted towards billion-year existential risk scenarios at the cost of present suffering: extreme poverty, factory farming, and climate change. He argues this shift may inadvertently cultivate callousness towards immediate, tractable harm.
- The Journal of Controversial Ideas exists because tenure alone no longer protects. Co-founded by Singer, the journal publishes peer-reviewed work — about a third under pseudonym — that established outlets reject on grounds of potential offence rather than intellectual merit. The most submitted topic at the time of recording was transgender theory. The journal’s lesson: institutional timidity has outpaced institutional protection.
- A meaningful life, not hedonic maximisation, is the practical utilitarian goal. When asked for life advice, Singer does not say ‘maximise pleasure.’ He says: live in harmony with your values, contribute to making the world better, and the psychological research suggests your life will be more rewarding. The utilitarian conclusion and the eudaimonist conclusion converge.
Content
The limits of utilitarian reasoning
Cowen opens with a series of thought experiments designed to test where utilitarian reasoning breaks down. Would Singer wish that humans had never settled the New World, freeing more intelligent mammals? He concedes the question is intractable — not philosophically, but empirically: we cannot compare the well-being of displaced bison with the happiness of the humans who displaced them. He is similarly agnostic about whether eight billion people is ‘too many,’ because the answer depends on technology, energy, and how one weights human against nonhuman flourishing.
What Singer resists is concluding from this intractability that utilitarian reasoning yields nothing. His standard move is to redirect to cases where the numbers are not close: factory farming, he says repeatedly, is a domain where we can be ‘very confident’ the harm exceeds the benefit, and that confidence does not require solving the hard comparisons.
The expanding circle and its Darwinian limits
Singer is unambiguously Darwinian about human nature — he wrote A Darwinian Left and has not moved from it. He accepts that humans evolved to be self-interested, tribalistic, and indifferent to distant others. But he rejects the inference that reason cannot expand the circle of moral concern. Reason is itself an evolutionary product, and it can generate conclusions that override narrower impulses, at least for some people some of the time.
Cowen presses the pessimistic reading: rationality is selective and domain-specific; the same person who reasons carefully in one domain will ‘do terrible things’ in another. Singer’s reply is measured — he does not claim reason wins universally, only that there is evidence a ‘dominant group’ capable of more general ethical reasoning is possible, and that its reach may grow. He treats this as an empirical question still open.
Aliens, impartiality, and species loyalty
The conversation’s sharpest exchange is the alien thought experiment. Cowen proposes: if wiser, happier aliens could rule Earth better than humans, should we side with the aliens? Singer says yes — without hesitation. If the calculation genuinely favours overall welfare, species loyalty is simply partiality dressed up as principle. He explicitly rejects Bernard Williams’s concept of ‘ground projects’ — the idea that an impartial ethics that could ask you to die for the greater good is self-undermining. For Singer, that intuition is just tribalism at the species level.
Cowen pushes back: ‘You’re selling out your fellow humans.’ Singer’s reply cuts to the core of his position: ‘I don’t claim to have any particular loyalty for my species rather than the general good.’ Whether this is a strength or a reductio depends on whether one accepts that a common metric of happiness can, even in principle, span species.
Effective Altruism: diagnosis and prescription
Singer’s ambivalence about the movement he helped inspire is careful and specific. He views EA positively as a forum and as a generator of influence. His concern is not with longtermism as such — he understands why William MacAskill emphasises preventing extinction — but with the practical effect of encouraging people to ignore present suffering in favour of speculative trillion-year calculations.
His prescription is a rebalancing, not a reversal: a ‘major focus, not an exclusive focus’ on reducing extreme poverty, animal suffering, and near-term climate change. He also suspects that AGI existential risk receives disproportionate attention partly because it is an intellectually interesting problem, and interesting problems attract researchers.
The Journal of Controversial Ideas and the limits of tenure
Singer co-founded the Journal of Controversial Ideas as an open-access, pseudonym-permitting journal for work that peer reviewers accept as intellectually serious but that conventional outlets decline for reputational reasons. A striking example from the most recent issue at time of recording: a paper co-authored by 29 scientists, including two Nobel laureates, arguing that hiring and grant allocation should prioritise scientific merit over diversity metrics — submitted to the Proceedings of the National Academy of Sciences and rejected on grounds it ‘might be harmful to some people.’
He is frank that tenure no longer functions as the protection it was designed to provide. University administrations have failed to shield tenured faculty from social-media pressure campaigns. The journal exists in part to create an alternative record — and, in its pseudonym provision, a limited form of protection — for ideas that institutions no longer reliably defend.
Philosophy, Hegel, and why professional philosophy is boring
Singer is willing to agree with Cowen’s provocation that most professional philosophy is dull. His diagnosis: the tenure system rewards incremental work in established subfields because that is what peer reviewers in those subfields can evaluate. Young philosophers cannot afford the risk of working on broader questions. The result is philosophy aimed at the ‘capillaries’ rather than the lifeblood of the subject.
On his own philosophical influences: he learned from Hegel — before Marx, whom Hegel influenced — that economic interests shape ideas. He regards Henry Sidgwick as the best of the 19th-century utilitarians and underrated; he and Katarzyna de Lazari-Radek wrote The Point of View of the Universe to make that case. He is kind but critical of Derek Parfit’s final trilogy: the project to reconcile consequentialism, Kantianism, and contractualism is admirable, but Parfit became ‘so committed to the idea that he had to show that morality is objective’ that it warped his acceptance of weaker arguments.
On living well: the utilitarian life advice
In the conversation’s closing movement, Singer is asked — as a mental-state utilitarian who cares about happiness — what advice he would give for enjoying one’s own life. His answer is not hedonic: don’t pursue money and consumer goods, but find a life that is fulfilling and meaningful, and in harmony with your values. He cites psychological research showing that generous, values-aligned people report more rewarding lives. The utilitarian calculus and the classical advice about virtue converge on the same practical output.
Related
- Peter Singer — speaker; author of Animal Liberation Now and Practical Ethics
- Tyler Cowen — host
- Effective Altruism — movement Singer co-inspired; his advice is to rebalance towards present suffering