"Peter Singer and Fifty Years of Animal Liberation" by Daan Stoop (Keywords: Suffering; Animal Welfare; Veganism; Factory Farming; Food Ethics)

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In 1975, Australian philosopher Peter Singer asked a deceptively simple question of animals: ‘Can they suffer?’ The implications launched a revolution in our thinking about animal rights and food ethics. But has animal suffering diminished in the fifty years since?

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For several years, fierce debates played out in the pages of The Vegetarian Messenger, the journal of the British Vegetarian Society. The club had been around since 1847, but between 1909 and 1912, it faced a pressing question: can we still justify the consumption of eggs and dairy?

In 1935 — a generation later — the journal’s editor-in-chief would call the dilemma ‘more pressing year by year’. Donald Watson, a woodworking teacher from Leicester, championed a diet of (mostly ground) nuts, Canary bananas, apples, and dates, and believed in total abstinence from animal products.  However,  most members of the British Vegetarian Society found themselves in a state of transition.

By the end of World War II, Watson, his partner Dorothy, and four other like-minded souls had had enough. As ‘non-dairy vegetarians’, they felt increasingly sidelined in the society’s publication. So they forged their own path, coined a new word — ‘vegan’ — and founded a society of their own. They wanted to exchange their government-issued butter and lard rations for lentils or dried fruit, but the authorities denied their request. ‘Just take extra eggs,’ civil servants wrote back. Watson saw this as a discriminatory stance against what he recognized as a then-tiny movement. Only twenty-five Britons, he would later write, seemed to care about what he controversially called  ‘that other holocaust, which goes on all the time’.

Despite Britain’s postwar transformations — decolonisation, cultural upheaval, the rise of welfare institutions — the Vegan Society remained on the margins. A few hundred people joined each year, and its newsletter reached, at most, a few thousand households. The idea of abstinence from animal products had not yet found its moment.

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A quiet shift began over lunch one day in 1970 with an Australian philosophy student at Oxford. Without much thought, twenty-four-year-old Peter Singer spooned spaghetti with a dark red meat sauce onto his plate in the Balliol College dining hall; the lunchtime discussion revolved around that morning’s lecture on free will, autonomy, and moral responsibility. When his tablemate, Canadian philosopher Richard Keshen, heard there was meat in the sauce, he opted for a salad — a rare choice at the time. A conversation about meat-eating ensued, sparking a shift in Singer’s thinking that would never subside.

Three years later, Singer published ‘Animal Liberation’, an essay in The New York Review of Books that resonated widely. It laid the groundwork for his seminal book of the same name, which popularized a moral principle that has hardly lost its edge: that it is not intellect or language that grants moral standing, but the capacity to suffer. With unflinching precision, Singer described the lives of animals in laboratories and factory farms. His ideas filtered into legislation, education, and consumer behavior, laying the foundation for the modern animal rights movement.

It is not intellect or language that grants moral standing, but the capacity to suffer.

Today, Singer is regarded as one of the most influential philosophers in the realms of animal rights and food ethics. This year marks the fiftieth anniversary of Animal Liberation, prompting renewed reflection on its legacy. Have Singer’s contributions to philosophy brought us any closer to a world in which animals are better off?

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‘To be honest, I had expected the book would have more of an impact on people’s eating habits than it ultimately did,’ says Singer, now seventy-eight, in a phone interview I conducted with him this year.

Animal Liberation delivered a message that was radical for its time but essentially simple and rational: the importance of asking of all forms of life, ‘Can they suffer?’ This question, which Jeremy Bentham had once scribbled in a footnote, became Singer’s moral cornerstone, accompanied by the conviction that not thinking, nor speaking, but suffering marked the boundary of moral concern.

With the publication of Animal Liberation in 1975, Singer marked the outer limits for inclusion in the moral community somewhere between shrimp and oysters, a determination he continues to uphold. At the time, he described his book as a challenge to recognize our attitudes toward nonhumans as prejudices just as indefensible as racism or sexism. The book argues that speciesism, meaning the favoring of one’s own species, deserves the same rejection. It also calls for a boycott of animal products and concludes with some of his favorite vegan recipes, including Renata’s borscht (his wife’s recipe) and Sichuan-style stir-fried potatoes.

It is estimated that between five hundred million and one billion people now eat mostly vegetarian diets, of whom eighty to one hundred million are fully vegan. Meanwhile, global meat consumption has risen to more than 360 million tons per year — nearly three times what it was in 1975. The number of animals slaughtered annually for food has skyrocketed to at least eighty-four billion each year.

We need to envision a society in which animals are politically represented, their environments count as political spaces, and their behavior is recognized as a form of expression.

Laws and public awareness have progressed over the past fifty years, notes Dutch philosopher and artist Eva Meijer, but those gains are mostly symbolic, while actual animal suffering has grown exponentially. Factory farming has rapidly expanded and animals continue to be used in large-scale laboratory research. In Dutch labs alone, hundreds of thousands of mice are killed each year to generate knowledge for human benefit. ‘Clearly,’ says Meijer, ‘animals are not better off than fifty years ago, because vastly more of them are killed each year.’

Meijer sees Animal Liberation as a turning point in the world of animal rights and appreciates Singer’s role in sparking the debate, but finds his utilitarianism too narrow. His focus on suffering, they argue, neglects the complexity of animal lives. Rather than viewing animals solely as beings we must care for morally, Meijer envisions a society in which animals are politically represented, their environments count as political spaces, and their behavior is recognized as a form of expression.

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‘Technologically, the world looks completely different now,’ Singer says from Singapore, where he is currently a visiting professor. A day before our conversation, the Netherlands passed a law banning the maceration of male chicks in the egg industry. Thanks to a newly developed technique, their sex can now be determined before hatching, so male eggs can be destroyed before any capacity for feeling — and thus suffering — emerges. ‘Definitely a step forward,’ says Singer. He remains cautiously optimistic about such technologies, which are increasingly applied throughout the EU.

Singer warns that such positive developments paint an incomplete picture. While Europe has advanced in legislation and awareness, conditions worldwide have worsened. China, in particular, has seen a dramatic decline in animal welfare. In 1975, the country had little factory farming; today, it has more farmed animals than any other nation. This is not simply a matter of choices about domestic regulation or awareness, but of global economic forces — namely, the spread of intensive farming models, fueled by rising demand and the logic of industrial capitalism. Singer calls it a ‘depressing reality’.

In 2023’s Animal Liberation Now, the revised edition of Animal Liberation, Singer replaces outdated examples with new ones that are just as appalling. He calls the chapters on animal testing and industrial farming ‘shocking, both then and now’. Yet this grimness doesn’t prevent him from staying clear-headed. ‘I deliberately avoid emotional language,’ he once told The Guardian. ‘I’ve never considered myself an animal lover and I don’t want to speak only to animal lovers. I want people to see this as a fundamental moral wrong.’

Animal Liberation Now describes how old battery cages were replaced by ‘enriched’ ones; and how lab animals, while now somewhat better protected, are still used on a massive scale. The logic of exploitation remains: animals are still treated as machines that convert cheap feed into profitable meat. What appears to be progress often turns out to be merely cosmetic.

"I’ve never considered myself an animal lover. I want people to see this as a fundamental moral wrong."

‘Behind welfare labels and legislation often lies a harsh reality’, warns Frederieke Schouten of the Dutch animal welfare advocacy NGO Dier&Recht. A former livestock veterinarian, Schouten realized she could do more for animals through legal action and joined several non-profits. While she values moral appeals and awareness — which she says are essential to move judges to act — she stresses the importance of legal strategies. ‘Strategic litigation is essential for enforcing structural change,’ she says. ‘Much animal suffering remains hidden, even in Europe. It’s shielded by seemingly positive legislation. Abuses stay out of sight. Legal frameworks and ethical awareness often stall at good intentions, without real change.’

Take the ban on veal crates: even after its implementation, calves still spend weeks in isolation without straw, toys, or social contact. The ‘crate’ is slightly larger, but the calf remains confined. ‘That’s what we call animal welfare,’ Schouten says. ‘But for the animal, little changes.’

Back in 1975, Singer made clear that such cases were not exceptions, but structural practices reducing animals to tools. He described in chilling detail how calves were removed from their mothers shortly after birth and fed an iron-deficient diet to induce anemia, all to yield more tender meat; and how fish were transported alive, gasping on dry land before suffocating. These and many more forms of suffering were widespread then — and despite five decades of progress in the field of ethics, such practices have by no means disappeared.

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Even in countries where animal welfare is now part of the political agenda, implementation still lags behind both public concern and political rhetoric. Although Australia, Singer’s country of origin, has an Animal Justice Party, laying hens are still kept in cages there that the EU banned in 2012. Australia plans to phase them out only by 2032, showing how non-committal animal protection remains; what measures are taken hinges largely on perfunctory political will and public pressure. We are kept at a safe distance from the violence of slaughterhouses — behind welfare labels, walls, and marketing. Thanks to National Geographic, the average viewer knows more about sharks and leopards than about pigs and chickens.

In keeping with Singer’s conviction that progress begins with visibility, vegan investigative journalist Roel Binnendijk shows what truly happens on the slaughterhouse floor in his book Onder de beesten (Among the Beasts). For three years, Binnendijk worked undercover in Dutch farms and abattoirs, armed with a hidden camera. He captured duck catchers using live animals as footballs or stomping them to death; and pigs being kicked, beaten, dragged by their ears, and shocked in the genitals. His footage made national news.

Because laws so often fall short, victories are frequently won outside of the courtroom. Labs have shut down, retailers have dropped fur, and supermarkets have revised their sourcing policies — not out of conviction, but under pressure from consumers and activists. These ‘private victories’, some argue, are necessary interim steps, precursors to a more just legal order. But how meaningful are minor improvements — a bit more space, a little less stress — if billions more animals are suffering because we consume so much more meat?

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Donald Watson, the British woodworker who coined the term ‘vegan’ in 1944 and founded his own society, spent much of his childhood on his uncle George's farm. Witnessing the slaughter of a pig there shook him to the core; the romantic image of farm life shattered, replaced by a claustrophobic death chamber. He changed his diet and became a vegetarian at fourteen.

The pig Watson saw die probably barely resembled the pigs raised in today’s factory farms. Not only has the number of farmed animals increased, but the nature of their suffering has changed. Industrialization has turned animals into fragile, specialized ‘machines’, dependent on antibiotics and protein feed. Piglets today are bred for rapid growth and maximum meat yield. They have broader shoulders, longer bodies, and more teats than their ancestors, to nurse larger litters. In the 1970s, a sow weaned about twenty-two piglets per year; today the average is thirty-two, with breeding firms aiming for forty. This intensified form of motherhood exhausts the animals. Many sows die young from the physical toll of their own productivity.

Industrialization has turned animals into fragile, specialized ‘machines’, dependent on antibiotics and protein feed.

Modern pigs are more prone to stress, more frequently lame, and live on bare concrete floors without straw or fresh air. They have nothing to root in. The distance between the pig Watson saw and the ones we consume today is not only historical, but biological. What remains unchanged is the suffering.

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What we put on our plates, argues writer Jonathan Safran Foer in his 2009 book Eating Animals, is not merely a matter of taste but a moral choice. He shows that our treatment of animals in food systems is not just economic or cultural, but reflects our identity. Massive animal suffering, he says, is made possible by the stories we tell to justify it — among them, those about tradition, health, necessity. But no story, Safran Foer argues, is innocent. Looking away is not a neutral act; it is siding with the perpetrator.

Safran Foer’s appeal resonates with Singer’s but shifts the focus from moral reasoning to moral imagination. He asks not only, ‘What is just?’ but also, ‘What kind of people do we want to be?’ That shift is crucial, especially in a time when suffering continues to grow on an industrial scale. Safran Foer doesn’t just challenge our principles — he challenges our character.

Safran Foer asks not only, ‘What is just?’ but also, ‘What kind of people do we want to be?’

In 1975, Singer — building on the work of female contemporaries like Ruth Harrison, author of Animal Machines (1964) — introduced a distinctly utilitarian case for animal rights. Today, his conviction that animals can suffer, and thus matter morally, is broadly shared, even by philosophers with different views. ‘The idea that animals are entirely irrelevant to ethics has largely disappeared,’ says Singer. ‘Even philosophers who don’t fully endorse my arguments now recognize that animals count.’

The horizon Singer wedged open fifty years ago has only widened. Thinkers from a wide range of traditions now challenge the old boundary between human and animal. Kantians like Christine Korsgaard argue that animals are ends in themselves, beings with an inherent worth we must respect; and feminist philosophers such as Carol J. Adams and Lori Gruen expose how the oppression of animals is intertwined with patriarchal structures and gendered hierarchies. While Adams critiques the cultural bond between meat and masculinity, Gruen calls for a relational ethic of empathy, rooted in connection rather than abstract calculation.

Religious voices, too, have joined the chorus. Theologian Andrew Linzey frames care for animals as a Christian duty of compassion; Buddhist philosopher Shih Chao-hwei grounds animal ethics in the principles of non-harming and interdependence. Others go further still, imagining animals not just as beings to be protected, but as participants in shared political communities. What began as a call to reduce suffering has grown into a richly plural conversation — broader in scope, deeper in method, and bolder in its moral ambition.

***

Singer’s central idea — that the capacity to suffer grants any being moral status — is still his guiding principle today. ‘To me, that’s still the only criterion that really matters,’ he says.

In later works like 1979’s Practical Ethics, Singer refined his utilitarianism and became more pragmatic, supporting interim measures that reduce suffering, like welfare improvements and meat substitutes. Throughout his career, his thinking has remained anchored in one principle: minimizing suffering. But his ethical scope has widened. As early as 1972, he had published Famine, Affluence and Morality, a call for greater global action against poverty. More recently, in affiliation with the effective altruism movement, his attention has expanded to include the climate and technology.

These days, Singer eats mostly vegan, except for the occasional oyster, and reflects on issues like AI, food policy, and animal agriculture — systems that can either relieve or intensify suffering, depending on who controls them and to what end. He remains committed to moral reasoning, but welcomes thinkers who build upon his work.. Reflecting on Eva Meijer’s contributions, he remarks, ‘Interesting — going further than my own position, but certainly valuable’.

Since Animal Liberation, a new motive for plant-based eating has emerged: the climate. The ethical focus on animal suffering now dovetails with widespread concern over greenhouse gases and biodiversity loss. But the goals of less animal suffering and lower emissions, while seemingly aligned, sometimes come into tension with one another.

The goals of less animal suffering and lower emissions, while seemingly aligned, sometimes come into tension with one another.

In 2024, Denmark became the first country to announce a carbon tax on cattle, pigs, and sheep. Climate activists cheered, but animal welfare experts sounded warnings. When the city of Aarhus tested a similar policy in 2022, beef sales dropped by forty percent — but demand for chicken and pork surged. Chicken is considered more climate-friendly than beef, but the change also meant more animals are going to be slaughtered, likely living shorter lives and under worse conditions.

Such a shift, Singer warns, increases suffering. One cow yields about 160 meals; a chicken, at most, four. Chickens are mass-produced in enormous, artificially lit barns, where up to twenty thousand birds live in cramped conditions. The air is thick with ammonia from their waste — and they have been bred to gain weight so rapidly that their immature limbs struggle to bear their own bodies. Focusing solely on CO2 emissions overlooks this suffering. ‘It’s a risk’, he says. ‘You emit less, but cause more animal suffering.’

Singer acknowledges that his original book said little about climate change; the topic barely registered in 1975. In the revised edition, the ‘environmental impacts of animal production’ takes center stage.

For him, the key to real change lies in structural reform: ending direct and indirect subsidies for animal farming and reorienting agricultural policy toward plant-based production. ‘Only if we fundamentally rethink the deeply entrenched economic logic of growing crops to feed them to confined animals — and reclaiming only a fraction of the nutrients — can the promise of Animal Liberation truly be fulfilled.’

Daan Stoop is a journalist and editor at De Groene Amsterdammer. He writes investigative and philosophical pieces on politics, ecology, technology and music.

The Dutch version of this article was published earlier in De Groene Amsterdammer.

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