Peter Singer has been called one of the most influential — and controversial — philosophers alive today. His pioneering work Animal Liberation: A New Ethics for Our Treatment of Animals, which vividly portrayed the harsh conditions for livestock on factory farms, helped spark the animal rights movement. The book, published in 1975, has now been revised and was reissued this week.
In an interview with Yale Environment 360, the 76-year-old Singer talks about how in the years since his seminal book was published, science has eroded the boundaries between humans and other creatures, demonstrating that animals can experience joy and also suffer. Knowing this, we are ethically bound to avoid causing them pain, he says. Singer, a vegan, also cites the environmental reasons to eat plants, which are less carbon intensive to produce than meat. Factory farming of livestock is on the rise worldwide, he notes, while wild animals are increasingly under threat.
Singer argues that protections increasingly afforded animals should be extended to ecosystems, rivers, and other natural features. The ethical demand to protect nature is growing, but slowly. “I do think the world will get there eventually,” he says, “but I can’t say when. I don’t expect to live to see it myself.”
A pig farm in New Zealand. Farm Watch via Flickr
Yale Environment 360: You are best known for your work on animal rights. Was there anything in your childhood or upbringing that sparked your interest in animals and your desire to lessen their suffering?
Peter Singer: No, I don’t think so, I was not an animal lover, and I still don’t consider myself an animal lover. I don’t want to have [pet] animals in my house. I appreciate their abilities more after learning about them. I empathize more with their suffering and their capacity for suffering, but I’m still not emotionally attached in the way that many people are emotionally attached usually to their companion animals, their dogs and cats.
My concern about inflicting suffering on animals came much more from my interest in ethics, which I only developed when I followed through on the ethical implications of what I found out about factory farming and the way that animals were being treated. That’s really what brought me into this area and led me to write Animal Liberation.
e360: You published that book nearly a half century ago. Why did you feel it was important to revise it now?
Singer: Well, it has never been out of print since 1975, which is unusual in modern publishing, so there is still a demand for it. But I was starting to get a little embarrassed that the factual information was from earlier than 1990 when we last fully revised it. These conditions in labs and factory farms have changed a lot since then. I wanted this book to still be relevant. It needed a very through updating.
“We shouldn’t inflict [pain] on others without a very strong justification. And the species boundary isn’t relevant.”
e360: I imagine that your own views have changed somewhat as well.
Singer: Yes, that’s right, inevitably they have changed to some extent, and of course the situation is different now. There is a whole animal movement that didn’t exist when the book was written, and that has gone in a variety of directions, including the suffering of wild animals. I wanted to comment on that. Progress has been made, so some of the things that I described that were really bad in the first edition have improved in some jurisdictions.
e360: When you first wrote the book, the very idea that animals had rights was considered marginal. Now it is more widely accepted, at least in principle — how do you account for that change?
Singer: I hope that it’s been in response to some of the arguments that I and others have put forward. I also think that the scientific work of Jane Goodall and Diane Fossey and others really helped to narrow that gap that we previously had thinking all humans are over here and over there is this vast collection of beings we call animals ranging from chimpanzees to oysters and they are all somehow in another moral category entirely. I think that’s been demolished by a lot of the work that’s been done, and not only on great apes but also on so many other species.
e360: You are a vegan, and the rationale for your veganism is based on the capacity of animals to feel pain more than on their intelligence. Why is pain the criteria?
Singer: We recognize that pain is a bad thing in ourselves. Just as we don’t like pain inflicted on us, we shouldn’t inflict it on others without a very strong justification. And the species boundary isn’t relevant. Pain is pain as long as a creature is capable of feeling it. And that seems to me to be a more simple and straightforward argument than one based on cognitive capacities.
A recent study found evidence that octopuses feel pain in a similar way to mammals. Martin Strmiska / Alamy Stock Photo
e360: How far do you take this? Can fish feel pain? What about plants? Do they have rights in your view?
Singer: With fish there is now a whole body of research that shows they can feel pain. There isn’t such a body of research with plants, and plants don’t seem to have the kind of nervous system that we associate with feeling pain. I do feel there’s a gray area between fish and vertebrates and at least some invertebrates that can feel pain. Recently the U.K. passed an amendment to its animal welfare legislation that recognized that cephalopods like octopus and squid and crustaceans like lobster and crab [can feel pain]. So I do think there are some invertebrates for which we have good evidence. But getting back to the oyster, it seems very unlikely that oysters can feel pain. So in my view it’s not true that all animals can feel pain.
e360: You write a lot in the book about meat production at a time when the conditions that livestock were being raised under were not well known. Have the practices of factory farming changed much since you wrote the book?
Singer: Europe and the U.K. have banned some of the worst forms of confinement for chickens where they can’t even spread their wings, as well as California and several other U.S. states. The confinement of calves in veal stalls so that they can’t turn around — that’s also prohibited in some places. Confining breeding sows in tiny stalls has also been banned in Europe and elsewhere. But in much of the U.S., conditions haven’t changed very much, and in some respects they have gotten worse.
Chickens are being bred to grow so fast that the birds no longer support their body weight. For the last couple of weeks, they are in pain just standing up, and they can’t sit down because they are raised on a kind of litter — wood shavings that are full of their droppings and has such a high level of ammonia in it that if they sit down, it gives them skin burns on their legs and chest. There is no legal control, and market forces demand the cheaper chickens that can be raised that way. Overall, the breeding of chickens, which is the largest number of farm animals, has intensified. It’s actually gotten worse.
“It is not OK to eat grass-fed beef because the animals have a good life. We need to think about the effect on the planet.”
e360: Why you think the U.S. lags behind Europe in terms of these kinds of reforms?
Singer: The agricultural industry is very powerful here, and money plays a bigger role in American politics than it does in European politics. In California there have been a couple of referendums to improve the lives of farmed animals. They both passed by large majorities, over 60 percent, and in Massachusetts there were even larger margins. So if you put it to Americans, they reject these practices. But there is no federal legislation at all regulating farm animal welfare. The agribusiness lobby has managed to defeat any attempt to change the rules.
e360: You also write about the abuse of lab animals. That situation has changed a lot since you wrote the book, hasn’t it?
Singer: It has changed, though not as much as I had initially believed when I set out to revise the book. Unfortunately, there is still a lot of pain and suffering inflicted on animals for not very significant or no benefit at all to humans. There is still a lot of toxicity testing of nonessential substances that goes on. But the FDA is becoming a bit more accepting of non-animal results now. Legislation went through Congress recently that said that they shouldn’t require animal research.
In Europe, you can’t test cosmetics on animals. You can’t even import cosmetic products that have been tested on animals. But there is nothing like that in the U.S. One area that has improved is experimentation on great apes like chimpanzees, which has essentially stopped.
The National Primate Research Center of Thailand, where a COVID-19 vaccine was tested on monkeys. MLADEN ANTONOV / AFP via Getty Images
e360: How important for you are the arguments based on climate change, that animal agriculture is more energy intensive and is a big contributor to global warming?
Singer: Well, people should be aware of it. Some people say. “I don’t eat factory farmed products, but I eat grass-fed beef.” It’s true that with grass-fed beef they have a reasonably natural way of life and animal welfare concern are much less than with chickens and pigs and feedlot beef, but in fact the greenhouse gas emissions are still very high, so because of climate change I would not say that it is OK to eat grass-fed beef because the animals have a good life. We need to think about the effect on the planet as well.
e360: Growing vegetables has a carbon cost as well. How much of a difference is there between eating meat and eating a vegetarian diet?
Singer: There’s a really big difference in fact. I have graphs and charts in the book that show it. Pretty much all animal products are worse than the worst of the plant products. Beef is by far is the worst. Then, the other ruminants, like lamb. Even dairy is pretty bad, although you get more protein and calories out of dairy than you do from beef. Maybe the best animal product from the greenhouse gas point of view is eggs, but even that is worse than pretty much all of the main plant products — the grains, the soybeans, and the like.
e360: You’ve written mostly about the cruelty to farm animals. What about destroying wildlife habitat, driving them to extinction — isn’t that an equal or greater violation?
Singer: The arguments for biodiversity and against extinction are another category of argument because they are not focused on individual animals [but rather on species]. You need a different argument for preserving biodiversity and preventing extinction. Of course there are such arguments. And as you say, environmentalists are making them.
“It is a different ethical argument if you are talking about things that are not sentient, like rivers and mountains.”
e360: Some environmentalists have argued that legal rights should be extended to geographical features like rivers, mountains, and ecosystems. Is there an ethical basis for extending rights to these natural systems?
Singer: To me, the ethical basis is the responsibility of this generation to pass on things that have existed for millions of years to future generations. To destroy these things is a kind of vandalism. Just as what the Taliban did to the Bamiyan Buddhas is clearly wrong, so too it is wrong to dam a wild river. It is a very different ethical argument if you are talking about things that are not conscious and sentient, like rivers and mountains. But I do support countries that have such legislation that recognizes those rights.
e360: You’ve written that global poverty, climate change, and the way we treat animals are the top three ethical issues facing us today. Are these three connected in your mind?
Singer: Yes, they are connected. In all of them, there is a lack of concern for distant others. The distance can be geographic — they’re somewhere like Africa, so I don’t have to be concerned about them — or it can be economic — they are poor [so I can ignore them]. With climate change, the distance is temporal. The people who will be worst affected by climate change will be living at the end of this century and maybe the next century. And there is a biological distance between us and other species. They are distant relations. We’re less concerned for animals for that reason.
e360: Is the move toward fully recognizing animal rights inevitable?
Singer: I do think the world will get there eventually, but I can’t say when. I don’t expect to live to see it myself.
This interview was edited for length and clarity.