Since 1999 I've been the Ira W. DeCamp professor of Bioethics at Princeton University. I've written or edited about 40 books. In 2005, Time magazine named me one of the world's 100 most important people. I am also the founder of The Life You Can Save [], an effective altruism group that encourages people to donate money to the most effective charities working today. I am here to answer questions about ... well, about whatever you like, really, in ethics, but especially about my most recent book, Famine, Affluence and Morality, published on December 1 by Oxford University Press. It contains a classic essay I wrote in 1972 that has been read by many of the founders of the effective altruism movement, and also has two other essays and a new introduction, as well as a preface by Bill and Melinda Gates.

Thanks everyone for your questions! Sorry, I had to go at 4pm, so apologies to all those whose questions I could not answer.

Photo proof:

Comments: 476 • Responses: 33  • Date: 

Mestop58 karma

Hi! What suggestions would you have for someone who wants to make a positive difference in the world?

thepetersinger138 karma

Donate to highly effective charities (you can find my choice here: and go vegan (or as near to it as you can manage).

PolitePothead46 karma

Hello. I'm a fan of your work on animal welfare and effective altruism, two causes I fully support. You are undoubtedly known for your utilitarian ethical position, specifically preference utilitarianism. However, I heard that you have recently switched to hedonistic utilitarianism. Is this true? I am wondering which form of utilitarianism you currently support, and what your current thoughts are on the various divisions (hedonistic vs. preference, total view vs. prior existence view vs. average, negative vs. normal/positive). Thank you.

thepetersinger38 karma

Yes, it's true, I currently consider myself a hedonistic utilitarian. The reasons for this change are best explained in this book: Re the other choices you ask me about: average utilitarianism is hopeless, so if I have to choose between that and total u, I will choose total, but perhaps there is some other theory out there that does better still - in my book Practical Ethics I've regard something I call the Prior Existence view as the main alternative to total U. And negative U is also hopeless. But the alternative to that is just utilitarianism, not "positive utilitarianism".

KalopsianDystopia42 karma

Do you think that suffering of animals living in the wild is an important ethical problem? Suppose for example that the fight for a vegan world is over and humans no longer hold any animals in captivity.

Would you be in favour of the negative utilitarian approach, i.e., trying to reduce the number of wild animals? Would it be better to leave the wild animals alone and simply not try to reduce their suffering? Or do you think that perhaps some genetic modifications to those wild animals would be most ethical, reducing their ability to feel pain?

EDIT: A typo.

thepetersinger39 karma

If we can reduce the suffering of wild animals, that would be a good thing to do. But should we reduce the number of wild animals? Only if we believe that wild animals suffer more than they enjoy their lives. (As you can see, I am not a negative utilitarian).

-cause28 karma

In your opinion, what is it that determines whether or not a creature deserves to be given equal consideration for the opportunity to a life free of suffering?

To follow up with a related question, there is often a lot of talk about whether or not it is permissible to eat animals that lack central nervous systems and thus, most likely do not experience pain in a way which resembles the way we experience pain; examples often used are oysters and mussels. Could you perhaps clear up the confusion here?

thepetersinger56 karma

My view is that we ought to give equal consideration to the interests of any being that has interests. By interests I mean that the life of the being can go better or worse for that being - there must be subjective experiences, or consciousness. So the principle is really about giving equal weight to the similar conscious interests of all being.
The issue about beings without a central nervous system is whether they can have conscious experiences. Maybe some can, but I'm doubtful that bivalves like oysters and mussels can. If I'm right about that, it is OK to eat them. If you think it is doubtful, give them the benefit of the doubt.

Life-in-Death21 karma

Considering that clams, for example, have ganglia, opioid receptors, eyes, and are motile, do you not think it is better to exercise caution if eating them are not needed for survival?

thepetersinger34 karma


nicholas81826 karma

Hello. Thanks for doing this AMA! My history teacher had this question for you:

From the standpoint of effective altruism is it a preferable strategy to live frugally and save/invest a great deal (rather than giving large amounts to charity) in order to leave the whole pot to charity upon one’s death?

(assuming that you pick the perfect charities to donate to)

thepetersinger83 karma

It's better to give now, UNLESS you are a really smart investor (eg, the next Warren Buffett). Because there is a return on investment in poverty reduction too -- if families live better, their children will be healthier, will get a better education, and will get better jobs, and stimulate the economies of developing countries, thus reducing poverty and suffering in those countries, and it is better that this should happen sooner rather than later.

-cause24 karma

In a 2009 interview with Slow Food International, you state that, "The vegan diet, especially buying organically produced plant foods, does solve more of the ethical problems about eating than any other. But I admit that it is not for everyone, and it will take a long time before it becomes widespread."

Perhaps this is an odd question but, reading through this interview made me wonder, what sort of diet do you yourself have? Are you a vegan, lactovegetarian, ovo-lactovegetarian, ect.?

On a similar note, what are your thoughts on in vitro meat and in what are your thoughts on the impact it might have in the future?

thepetersinger38 karma

I describe myself as a flexible vegan. That is, I'm vegan when it's not too difficult to be vegan, but I'm not rigid about this, if I'm traveling for example.

iramusa19 karma

Hello Professor Singer,

I am a PhD student of Robotics from Edinburgh. Some of current robots run with algorithms which rely on punishment and reward system (reinforcement learning). These robots try to complete some task and are in "pain" if they fail. Do you think it is ethical to apply punishment to those agents? What features robot requires to make it equally morally relevant as human?

These algorithms could be rewritten in a way that is functionally equivalent and not using reinforcement learning (i.e. you could not distinguish two robots with different code). Is there any value in doing that?

Do you think we will be able to ultimately disseminate what is so important about pleasure and suffering of others? Is it possible that after some years of research we decide that not caring about other beings' utility is the way to go?

thepetersinger34 karma

Do you think these robots are conscious beings?
I assume not, in which case they are not feeling pain, and so they are not really being punished. I hope that we will never cease to care about the utility of conscious beings! In general, the trend is in the opposite direction (see my book The Expanding Circle - you can find info on it, plus a conversation between me and Robert Wright, here:

ADefiniteDescription8 karma

Were Strong AI possible, and AI were conscious, would that be enough for you to think they feel utility? Let's assume that they have nothing to realise pain (or substitute whatever account of pain you like). Are AI worthy of moral considerations if they cannot have physical sensations?

thepetersinger16 karma

if they are conscious, yes.

MichaelExe19 karma

What are your thoughts on animals suffering in the wild? Does it seem hopeless to try to help? It think we could certainly help many, so it may not be pointless, but it doesn't look like a problem we'll ever make a dent in. Just the issue of predation alone is huge. Should we stop a lion from killing a gazelle?

EDIT: there's a comment of his on this topic here (although from 1973).

thepetersinger35 karma

We don't want lions to starve to death, or gazelles to overpopulate and overgraze the grasslands. We don't really have solutions to these problems, so it seems better to focus on the things we already do have solutions to, like factory farming. And if you want to know how to do that, support these charities:

anonymous911118 karma

Hello Mr. Singer, congratulations on your great books. A question concerning animal welfare: Taken that some (including you) compare the treatment of animals to the "Holocaust", do you think it is enough to donate money, become vegan, and engage in EA stuff or ought we engage in less restrained action which we would very strongly consider when regarding any other Holocaust to attempt and immediately stop animal suffering?

thepetersinger43 karma

I generally avoid comparing the treatment of animals with the Holocaust, though I may have done it once or twice, many decades ago. The animal movement suffered a huge setback in the 1980s when a few violent acts enabled our opponents to pin the "terrorist" label on the movement. Don't go there again.

7firecrackers18 karma

You were recently interviewed by Professor Lawrence Krauss of Arizona State University for an excellent conversation that included topics in animal ethics (part one is available here and part two is available here). Would you consider asking someone with the copyright to upload a video to YouTube that includes only your dialogue on the ethics of eating so we can share the video online and promote vegetarianism? Namely the clips from 45:49 - 1:07:00 in part one and 21:35 - 30:15 in part two. You could make the case to them that it would be a great way to bring some attention to the The Origins Project. (I emailed and called them with this request to no avail.) Thank you for your consideration!

thepetersinger31 karma

OK, that's up to Lawrence Krauss, but I can pass on the idea and indicate that I support it.

WhySpace17 karma


Why do you concentrate so much on a measly couple billion people suffering today, rather than the 10’s of billions or even trillions of people yet to be born?* It seems like even a small change in the order technologies are developed in could dramatically impact the trajectory of our civilization to avoid astronomical loss, do astronomical amounts of good, make utopian futures more likely, and make dystopias less likely.

*Number range is extremely rough, and assumes that roughly half of people who will ever exist have already been born.

thepetersinger32 karma

I haven't seen any clear explanation of what we should be doing to make this dramatic improvement in the trajectory of our civilization. If we had a good understanding of how we could do this, it would be a different matter.

trulspetersen17 karma

Hello Peter Singer!

I am a anti-speciesist history teacher, and I wonder what you think about educating children about speciesism in schools? I have myself thought about incorporating into my teaching matters such as changes in attitudes towards animals over time; industrialization of slaughter; animal testing; the (by some) alleged interconnectedness of opression (e.g. domestication of animals - slavery, experimentation on animals - experimentation on humans), etc.

I suspect education about speciesism might generate violent opposition, but on the other hand I feel hypocritical in excluding one form of opression from my teaching whilst working extensively with other forms of opression.

thepetersinger21 karma

My wife used to be a school teaching, in English and humanities, and she incorporated some discussion of animals and speciesism into her teaching. She got some pushback, but not a huge amount, and there would be less now, I suspect.

Ihr_Todeswunsch16 karma

Thanks for doing this Professor Singer.

I'm curious on what you think of Antinatalism. I feel people's interest in this topic has grown in recent years, especially from the show True Detective. In our secular culture without a God or anything to base our morality, people are starting to consider the idea that if suffering is bad, then why create something that will suffer at all?

I've read your posts on the NY Times where you talked about Professor Benatar's book Better To Have Never Been, and you gave a charitable reading on it, saying that the view isn't crazy despite what most people might think at first. But you ultimately disagreed with him saying that while you don't think that there's anything morally wrong with a non-sentient universe, you still feel that most people enjoy their lives enough to justify procreation. I agree with you to an extent, but one of the Antinatalist's attack is that it's coercing people into suffering without their consent. There may be an identity issue in there (how can something which doesn't exist be coerced?), but something also sounds right about it. No one asked to be born. In this respect, is it immoral to procreate because we're forcing people to live without their consent?

thepetersinger30 karma

No one asked not to be born either. I think that cancels out the argument that no one asked to be born. We have to make the decision for them ,and we should make it on the basis of our judgment about whether their lives are likely to be worth living.

-cause16 karma

In your book Animal Liberation you state that, "the researcher's central dilemma exists in an especially acute form in psychology: either the animal is not like us, in which case there is no reason for performing the experiment; or else the animal is like us, in which case we ought not to perform on the animal an experiment that would be considered outrageous if performed on one of us".

My question is, do you think that, under certain circumstances, an experiment performed on animals could be considered permissible even if that experiment was one which we would consider outrageous if performed on humans? If so, under what circumstances would you consider experiments such as these to be justifiable and, how can we go about drawing the line between what is "right" and what is "wrong" when it comes to experimentation on animals; especially when some (albeit, very few) of the experiments in question have made significant progress in the field of medicine in recent years; or could perhaps make significant progress in the near future (both for humans and non-humans)?

edit: a word

thepetersinger31 karma

It's possible that an experiment on animals could be considered permissible even if most people would consider it outrageous if performed on humans. There might be different factors that are relevant, such as the fact that humans could fear that they are at risk of being used as subjects of such an experiment, whereas animals would not be able to know about this, and so could not become fearful in the same way.

-cause14 karma

There has been a lot of recent debate on the topic of genetically modified organisms (GMOs), specifically in relation to foods. You yourself have written a decent amount on GMOs and your opinion, more or less (correct me if I'm wrong), is that "regulations to protect the environment and the health of consumers should be maintained. Caution is reasonable. What needs to be rethought, however, is blanket opposition to the very idea of GMOs."

Personally, I agree. What my concern is, and I will admit that my knowledge on the subject of genetically modified foods is quite limited, is that I'm not sure about how these modified crops are effecting wild animals. Often referenced are animals such as bees and butterflies which GMOs may be harming unintentionally.

With that in mind, my question is, do we know whether or not genetically modified crops are effecting ecosystems in negative ways and, if we are unsure, do you think that it is ethically permissible to grow genetically modified crops in the ways that we do now when biodiversity is put at a possible risk by GMOs and thus, ecosystems and the sustainability of other species is put at a possible risk?

I realize that my question may be better suited for someone working in the related scientific fields of study, yet, given that you have discussed GMOs in depth in the past, I figured that you might be able to address my concern at least in accordance to the ethics involved.

thepetersinger44 karma

I don't think that there is clear evidence that GMOs are hurting bees and butterflies.. one early study on this caused alarm, but was later shown not to be valid. Yes, there may be some unknowns, but where a GMO crop has promise of substantial benefits, eg golden rice, or a drought-resistant wheat, it will be worth taking some risk, if we can minimize the risk.

edmantes12 karma

First a brief thank you. I've been meat free for close to two years now and I feel mentally a lot better for it and your writing and recordings of your lectures were definitely an influence on my decision.

I was wondering if you have any views on a situation that I've encountered a few times when it comes to charity in the work place.

People seem happy, at least in anywhere I've worked, to donate money to say someone in the office who is running a marathon in support of a breast cancer charity and seem to be fairly positive about the person who is asking them to donate.

However, when socialising with these same people the subject of charity has come up and inevitably when I raise the prospect of my colleagues donating a sum of say 1% of their salary to charity there's an accusation of "being preachy" when ultimately it seems to be the same request but minus the random nature of the charities that benefit and the unnecessary act of one of us running 26 miles.

Do you think there might be an effective way to rally people around the idea of being more consistent and effective with their altruism in the way that they seem to rally around sponsored activities for seemingly random charities? Is this a problem of getting an idea into peoples' imaginations? Does the marathon or long distance cycle etc. act as some kind of empathy catalyst that I'm going to need to replicate if I want to get the idea of effective altruism across to my colleagues?

thepetersinger19 karma

there's some research suggesting that people do respond differently if you are challenging yourself by running, etc. Maybe you need to start training!

LordPigFarts11 karma

Hi Professor Singer! I was wondering if you could clarify your position on non-cognitivism vs. moral realism, and which category you fall into?

ADefiniteDescription4 karma

I think it would help if you pointed out why you think this is a tricky question, as you did in a previous thread.

ADefiniteDescription8 karma

Ah right, didn't remember the usernames. Here's the reason for those interested (and /u/thepetersinger):

Michael Heumer disagrees. In Singer's Unstable Metaethics[1] , Heumer describes Singer a non-cognivitist and provides a passage that is fairly convincing. I'd like to know if Singer identifies as such, or if he thinks Heumer is wrong in his description.

thepetersinger14 karma

I've changed my position since Huemer wrote that.

actuallynotazoophile11 karma

Hi Peter, firstly I love your utilitarian views and find they align very closely to how I feel.

Quick question, do you believe that zoophilia will ever be openly talked about as a legitimate sexual orientation, or will it always be just too taboo for society?

thepetersinger16 karma

Hard to predict, but given enough time, it's possible.

Anonymous1012201510 karma

1.) What do you think of Christine Korsgaard's attempt to provide a Kantian, rather than utilitarian, basis for including non-human animals in our moral thinking? Do you find it plausible?

2.) Do you think it is a coincidence that most of those who are receptive to the Effective Altruism movement (e.g. Parfit, Bostrom, Joshua Greene, and so on) seem to be consequentialists? Can you think of any non-consequentialists who are with you in this movement?

thepetersinger11 karma

It's not a coincidence that some of the best known EAs are consequentialists, but there are lots of EAs who are not consequentialists - for example, they believe that it would always be wrong to kill an innocent person, no matter what the consequences.

johngthomas10 karma

Hello Peter, you focus heavily on applied ethics, so I'm curious where you stand on a couple of other philosophical issues. Where do you lean on issues in philosophy of mind? How would you describe your position relative to thinkers like Dennett and Chalmers? Where do you lean on "free will"?

thepetersinger23 karma

I'm a compatibilist on free will, but I haven't thought enough about this issue recently for my opinions to be worth much.

Mayssen9 karma

If it would be possible to genetically modify animals as to not being able to develop any intelligence or preferences, would it be okay to eat their meat?

thepetersinger45 karma

It would still be a waste of grains and soybeans to feed them, and would still contribute more to climate change than eating a plant-based diet.

iramusa9 karma

Hello Professor Singer,

I agree that if you want to be moral, utilitarianism is the way to go. Why would I want to be moral though?

If you could take a pill that makes you more sensitive to other people's suffering (thus making you a better altruist) would you take it? Why?

thepetersinger14 karma

I'd take it, because that would be the right thing to do, and I think it is also the rational thing to do, both in the sense that it is what a purely rational being would do, and in the sense that it is what humans like us who want to live more fulfilling lives should do. I argue for the first of these claims in The Point of View of the Universe, and for the latter in The Most Good You Can Do. Some of the blogs on also address the question of why being an effective altruist is a personally rewarding thing to do.

joavim9 karma

Hello Professor Singer and thanks for doing this AMA.

What are your thoughts about the current migration crisis in Europe and the ways in which it has made war and poverty a very tangible thing for the average European?

thepetersinger9 karma

You can find my views on the refugee crisis here:

jackjizzle8 karma

Hello Professor Singer!

First of all - HUUGE FAN. Thank you for inspiring me and others. I just recently discovered Give Well and effective altruism. I've had utilitarian views for years.

  • What do you think of Give Wells work as a charity research organization and as a shortcut for people who are into effective altruism?

  • Are they conducting their research in the right way?

  • Do you think that we need more of these types of organizations?

thepetersinger11 karma

GW are fantastic, but we do need more options and some ways of including effective advocacy organizations. That's why The Life You Can Save uses a broader methodology. See here:

joelschlosberg7 karma

In A Darwinian Left you write that, like Marx's political ideas, Bakunin's anarchism "would no doubt also have gone awry" in practice. With Marxist central planning being far closer to actually existing capitalism's top-down firms than Bakunin's decentralism, and with a successful track record for the one time Bakuninism was tried on a large scale, during the Spanish Civil War (as extensively documented in Sam Dolgoff's The Anarchist Collectives), why are you so sure?

thepetersinger12 karma

I don't agree that Marxist central planning is all that close to current capitalism, and I remain skeptical about large-scale anarchism. A short-term wartime situation is unrepresentative.

Mintleton4 karma

Professor Singer:

  1. What is effective altruism?
  2. By what criteria can charities be measured against one another?
  3. Which charities do you recommend as effective?

thepetersinger14 karma

It's after 4pm, and I'm going to have to sign off. But for all of those interested in effective altruism, take a look at websites like, and also And if you are interested, btw, GWWC is having a special pledge event, check here:

Hongkie4 karma


I really appreciate your work and I firmly believe the world can and will become a better place if E.A. becomes widespread, common sense, and normative.

I have a few questions though:

1) Do you want your readers to take E.A. as some form of authority to follow? Or just one in many arguments in ethics and how to live a good live?

2) I know I'm closer to H. Simpsons than Homo Economicus, and what you propose seem really counter-intuitive, and comes across as unrewarding. (For example, I imagine using unique skills, such as surgeons volunteering to perform difficult cutting edge surgery, is more rewarding than resigning as human wallets and just work and donate.) It also seems to ignore human needs other than empathy (such as curiosity, challenge, accomplishment, social feedbacks, aesthetics, loyalty to own group, belonging.) I know you often state E.A. don't need to be saint, but do you consider it to be forgivable-unethical behavior to choose to donate to galleries and universities and perform expensive surgeries to save one life, as opposed to just leverage high salary to help the most dire and needy?

3) Do you think there are other things not measurable that are also worthy causes? Things like inspiring curiosity, aesthetic experience, will to innovate, experiences that lead to new knowledge/ fields etc? Most of there are extremely expensive, is it unethical to fund these instead of saving more starving children? Should I feel guilty for preferring to support these endeavors over inequality and poverty issues?

4) I promise this is last: how do you feel about arguments that rich nations intervention end up harming developing nations more than we help, by perverting incentive, by concentration wealth in corrupt government, by destroying markets that would have developed if not for our donations, etc etc? Is there absolute certainty that E.A. is the categorical best good we can do, or is there room for trials and errors and further investigations?

thepetersinger7 karma

These are all big questions and I can't answer them here. I discuss some in The Most Good You Can Do and you can find discussion of some of the others in the blogs on but the short answer is that different people enjoy different kinds of work, and there are good charities that do not contribute to the things you mention in your point 4. You can find them here:

ahamm953 karma

Hello Mr. Singer,

Just a few hours ago I took my final in my Intro to Ethics course, and there was an essay topic on the AMA and their claims about active and passive euthanasia. I was wondering what your personal opinion is on their to claims at the begining of the article, and whether or not you believ their claims to be a cop out when it comes to the topic of euthanasia?

We also read your book One World about the ethics of globalization. My professor mentioned how you two were colleagues and how your next/newest edition of the book will focus more on terrorism. How much more different will the book be with a focus on terrorism vs. the old one about globalization?

dfetz2 karma

On top of this, in regards to the euthanasia issue,I am in the same class as the OP and in the class we watched and discussed your film, A Dangerous Mind, you spoke a lot on the topic of euthanasia particularly in the Neonatal unit about a premature infant and the chance of it possibly not having any utility and it also not being able to make decisions for itself and your stance was the opposite of the physician who was saying do all that is possible to save the child. My question is this, if you were in the shoes of that physician I think we all know what decision would be made just by watching the film but would you choose an active or a passive route and in your mind is there a morally relevant difference between active and passive euthanasia.

thepetersinger14 karma

No, i don't think there is a morally relevant difference between active and passive euthanasia. And if passive euthanasia involves a slower, more drawn-out death, with more suffering, it's worse.

SkepticalVegan3 karma

How do you feel about genetically engineered crops to reduce resource and pesticide use and provide better nutrition?

Along those same lines how do you feel about current "cellular agriculture" projects to engineer yeast and bacteria to create animal products such as milk, cheese, egg, and gelatin?

Lastly how do you feel about cultured lab meat?

thepetersinger12 karma

I've already answered the one about GMOs in this AMA. I welcome all attempts to produce environmentally sustainable foods that involve no suffering, and can replace animal products.

Empigee3 karma

On what arguments do you base your suggestion that euthanizing disabled children and infants could be acceptable?

thepetersinger29 karma

In brief, we are already making life and death decisions for disabled infants - it happens in every neonatal intensive care unit, physicians and parents decide to turn off life-support because of the severity of the child's disabilities. I don't think it makes any real moral difference if we decide to end the life of a severely disabled infant by turning off a respirator, or by giving the child an injection. Do you?

BigRonnieRon2 karma


Vegetarian for the last 2 decades or so. Love your book Animal Liberation and a few of the others. Really thought the point regarding McDonald's being more influential in improving cage sizes than legislation in the revised due to their monopsony was fascinating. I'm increasingly beginning to believe legislative change is, for the most part, completely hopeless.

In light of that-

I see you promoting charity a lot. Which is great. Maybe it's different in the Uk or Australia where some of the charities you promote are, but on a macrofinancial level, in the US w/501(c)(3) private foundations (like the Bill and Melinda Gates Foundation), it's essentially a legalized system of tax theft from the public (monies which wealthy patrons would otherwise have to pay in personal taxes but can instead use towards personal and political ends under the guise of charity), and on a sociological level it ultimately justifies systems which create the problems charities attempt to mitigate while reproducing existing social class systems in its structure.

Not to say they're all bad, or this is intentionally so. So how do you combat that, and why would you support a private foundation when there are public charities and private operating foundations? Or any of them versus an expanded welfare state, worker co-operatives, etc?

While I hesitate to pursue the topic too strongly, as I tend to think the ineffectual nature of charity is often conversely used as a justification for selfishness, this is something of a reality especially with "charity brand marketing" like that employed by Komen to sell or worse "pink-wash" carcinogenic products and various other cancer charities or rampant theft by government figures (in Tibet for instance, notorious for its corruption).

thepetersinger8 karma

Yes, the US tax exemption for charities is far too loose. Changing that will not be easy. But some charities are good, and ought to be supported.