Given the choice between allowing five people to die, and killing one person, what would you do? What is the utilitarian argument for vegetarianism? Should we be able to sell our kidneys? The philosopher suggests some answers and picks the best books on 'ethical problems.'

What is ‘applied ethics’?

Applied ethics is the application of moral theory to the real world. I first read the five books that we are going to talk about here 25 years ago, which was the beginning of a burgeoning of applied ethics, with people like Jonathan Glover and Peter Singer applying theory to real issues like euthanasia, capital punishment, poverty, distribution of income, animal rights, abortion – questions of life and death.

Talking of which, I understand you’re a bit of an expert on “trolleyology”. What is a trolley problem?

There are two basic trolley problems. The first problem, invented by a philosopher called Philippa Foot, is that a trolley is going to kill five people on the rails. The question is whether you should turn the trolley onto another set of tracks on a spur where there is just one person. So you can save five lives at the cost of one life. Almost everyone, when you ask them that question, says you should do that and kill the one person.

Another moral philosopher called Judith Jarvis Thomson came up with another trolley problem, the “fat man” problem. The trolley is going along as before, and is going to kill five people. But this time you’re on a footbridge, and you can stop the train by pushing a fat man onto the tracks, who is so large that his bulk will stop the train and save the five lives. The question, again, is whether you should save five lives by sacrificing one. But 90% of people think it’s wrong to push the fat man.

Because it’s a more active way to kill the one man than in the first scenario?

That’s one possible psychological explanation. But there’s a third version of the trolley problem where instead of pushing the fat man, by turning a switch he will fall through a trapdoor, stop the train and save the five people. When you ask people that, most people still say you shouldn’t kill the fat man. More people are willing to turn the switch than push the fat man, but not dramatically more. The first trolley problem has been around since 1967, the fat man version appears in the 1980s, and nobody agrees exactly what the distinction is between them. It doesn’t look like it’s to do with the different actions.

The point of the trolley problem is to figure out what principle distinguishes those two variations – and, more importantly, what that tells us about real life cases. Can we apply that distinction to war, to medical ethics, to abortion? Originally the trolley problem was devised to explain the rights and wrongs of abortion. Today, it is often used in just war theory, the distinction between targeting a military installation knowing that civilians will be killed as bystanders, and directly intending the death of civilians.

At this juncture, will you give us a beginner’s guide to utilitarianism and how it impacts on these ethical dilemmas?

Utilitarianism is the view that you should do that which produces the most happiness or wellbeing. It’s a version of consequentialism, which is the view that you should do that which produces the best consequences – utilitarianism says that what matters most about those consequences is happiness. Utilitarianism has a wonderfully straightforward answer to all these thought experiments, that there is an algorithm or equation to working out what action produces the most happiness, and that is what you should do. Utilitarians don’t engage with trolley problems at all, for instance, because given a choice between five lives and one life, they say you should always take the one life.

What if it’s your mother?

I’ve never seen the trolley problem with your mother, but I have seen it put to the arch-utilitarian Peter Singer, whose own mother fell ill. He of course looked after her, but from a utilitarian perspective recognised that her life was of no more value than any other life. Utilitarianism has great difficulty in dealing with the special relations one has to one’s children, spouses, parents, friends and colleagues. They want to say that all lives are of equal value, and that we throw them all into this casserole of wellbeing, stir it around and see what the best result is, with no special obligation to our family and friends.

As such, utilitarianism seems common sense, but also cold and calculating.

I don’t mean to cast aspersions on utilitarianism, and when I was a student I classified myself as one. Scientists have subsequently discovered that when people are involved in car accidents and sustain damage to their ventromedial frontal cortex, they are more likely to reach utilitarian conclusions in some of these thought experiments than they were before. What that tells you about utilitarianism, I don’t know.

Read 1 Practical Ethics by Peter Singer Read

Let’s get stuck into your book selection, beginning with Peter Singer’s Practical Ethics.

Practical Ethics came out in 1979, just before I began studying philosophy. I loved its rigour, and I found Peter Singer almost impossible to argue with. I agreed with almost every position he took on every issue. There were chapters on abortion, on animal rights, on how much money we can give to the poor. It’s really the blueprint for everything he’s written subsequently. He is prolific, but if you want to know what Singer believes on a given topic, you may as well go back to Practical Ethics.

There’s a whole chapter on the fact that if we know that people are going to die in the Third World and we fail to do something about it, we’re as responsible for their murder as if we put a bullet through their heads. It’s a very practical book which addresses these controversial issues. I became a vegetarian at university after reading it, so it had a big effect on my life. I’ve since moved away from his very rigid utilitarianism on other topics, but I still find his arguments about how we should treat animals very persuasive.

What is his philosophical argument for vegetarianism?

He says that to claim that humans are more important than animals merely because they’re human would be what he calls “speciesist”, and no different from saying that white people are more important than black people merely because they’re white. If you say that humans are more important than animals, you have to give a reason. You have to say it’s because they’re smarter, or have the ability to plan for the future.

Now if you accept that premise – and I don’t see how you can’t – then there is a real problem of humankind’s overlap with some animals. If you say that what matters is our ability to plan for the future, then what about babies, or people with severe Alzheimer’s or who are mentally retarded, who don’t have that ability any more than chimpanzees do? Why do you think they are more morally important than animals? So once you accept the premise, you have to take animal suffering a bit more seriously.

Singer says that suffering matters wherever it is produced, and we should care about the suffering of any sentient creature. If we think that the benefit we get from eating meat doesn’t outweigh the incredible suffering of factory farming, then we should give up eating meat. And that’s why I’m a vegetarian. But Singer is completely logical about it. He accepts that if you were to eat only free range animals who lived a happy life at the end of which they were killed, there is almost nothing wrong with that. So there’s no reason why you can’t be an ethical meat eater, but you have to choose what meat you eat.

Read 2 Mortal Questions by Thomas Nagel Read

Next up is Thomas Nagel’s Mortal Questions.

This is a wonderful book, and completely different from Singer’s, although it’s also a series of chapters on different themes to do with life and death. He has a wonderful essay on equality, a great essay on war, and essays on consciousness as well, which is what makes living things different from dead things. What I love about Nagel is his ability to identify what really matters about a subject, and to write about it without getting caught in too much nitty-gritty detail. He’s a beautiful writer, and this and his subsequent book The View From Nowhere are two of my favourite philosophy books.

Nagel introduces in this book something that is completely counterintuitive until one thinks more deeply about it, namely panpsychism – the idea that inanimate objects might have atoms in which there is a conscious element. That sounds very weird until you think about human beings. We are created out of physical stuff, so where does the magical stuff of consciousness come from? Perhaps the answer is that the little bits of stuff which we thought was physical also contains within it some of this subjectivity, even if at a subatomic level. That seems crazy, but when you think about it, it has some plausibility to it.

Nagel has also written a lot about altruism. Wouldn’t the most moral solution to the trolley problems be to throw oneself onto the tracks?

That’s a very good question. The reason why you can’t throw yourself is because you’re not fat enough. That’s why the fat man has to be fat. The correct solution to the problem is to jump yourself and not kill anybody, but you can’t do that in this case, because you’re not fat.

Because you don’t eat meat, having read Peter Singer.

Quite possibly.

Read 3 Utilitarianism: For and Against by Bernard Williams & JJC Smart Read

In Utilitarianism: For and Against, Bernard Williams is against.

This is a book of two halves. The first half is written by a very eminent Australian philosopher and I can’t remember a word of it, but the second half was important to me. I was a pretty pure utilitarian until I read it, and it countered a lot of the influence of Peter Singer. Williams is a critic of utilitarianism – he thinks it is a deeply simplistic way to view the moral world. He gives a couple of famous examples which illustrate why, and which show the aspects of morality which utilitarianism can’t capture.

The first example is this. Imagine you’re in a Latin American country, and you come across a guerilla leader who is about to kill 20 Indians (a somewhat politically incorrect use of that term). He says, if you kill one of them, I won’t kill the other 19. Should you do it? Williams says that from a utilitarian point of view, of course you should kill the one person to save the other 19. But that’s to miss that it’s you who’s doing the killing. Utilitarianism sees everything from a bird’s eye view, and doesn’t realise that you’re involved with the consequences of your actions.

The second example is a character called George, who is very anti nuclear power. He’s short of money, needs work and is offered a job in a biochemical plant. The job pays well – means he can look after his wife and kids – and although he doesn’t believe in the work, if he doesn’t do it then someone else will do it even better, and promote this industry which he objects to. Williams again says that from a utilitarian point of view, George should take the job. But that fails to capture the question of integrity. Associating your life and career with something that you so deeply resent and oppose would be an attack on your integrity.

And surely you can’t calculate net happiness so simply. The dissatisfaction George might feel in the job could mean that he starts mistreating his wife and kids, who in turn take it out on others, and the unhappiness accumulates.

You could give that answer, but that’s an answer within the utilitarian framework. That’s saying that utilitarians have just got the calculation wrong – that they think this would make the world happier, but it won’t. To some extent you can quantify happiness. You know that 19 lives are better than no lives, for instance. Happiness is not an easy thing to measure, but you can say sensible things about what makes people happy and what doesn’t. But while your objection is saying that from a utilitarian point of view it might be wrong, Williams argues that even if utilitarians say the answer is clear-cut that George should take the job, that misses the issue of integrity.

Read 4 Reasons and Persons by Derek Parfit Read

Your next choice is Derek Parfit’s Reasons and Persons.

Reasons and Persons was written in 1984, and Derek Parfit was one of my postgraduate supervisors. One of the blurbs on the back of book says “Reasons and Persons is a work of genius”, and I think it is. It’s an incredibly important book, and one written in a tradition completely different to Bernard Williams, even though the two were friends. Bernard Williams is an essayist and he looks at the big picture, like Nagel. Parfit, more like Singer, is in the tradition of the 19th century philosopher Henry Sidgwick – he is a detailed, rigorous, almost mathematical philosopher, who worked from premises slowly to conclusions. There’s nothing pretentious about it – it’s beautifully written, incredibly thoughtful and well-argued, with fantastically imaginative thought experiments.

I’m particularly interested in the final chapter, about our obligations to future generations. There are various paradoxes that he tries to resolve. Here’s one of them. Suppose you knew that if you were to have a child, the child would have a terribly wretched life – it would be miserable, suffer for some years and then die. Would it be a bad thing to bring that life into the world, if it was going to be unremittingly miserable? Most people would agree that it would be. So does that then mean that it’s a good thing to bring a life that is better than nothing into the world? If you say it is, you get involved in what he calls the “repugnant conclusion”.

Imagine a world with a trillion people in it, all of whose lives are only slightly better than nothing – they have enough to eat and drink, but there is nothing really fulfilling about their existence. They aren’t leading the sort of flourishing life that you have, doing Five Books interviews. Compare that with a world in which there are only a few billion people, all of whom have a very high standard of living. Most people would say that the latter is better than the former. But if you think there is something worthwhile about every life where there is more happiness than there is suffering, then you reach the repugnant conclusion, which is that the world with a trillion people is better, because of the cumulative happiness of that greater population.

Read 5 The Sceptical Feminist by Janet Radcliffe Richards Read

Your final pick, The Sceptical Feminist, is conveniently by Derek Parfit’s wife, Janet Radcliffe Richards.

Parfit was my BPhil supervisor, Janet was my DPhil supervisor. I kept it in the family. This is another book that comes from the same generation of 25 years ago. It may be that books of that era have had more influence on me because I was young and impressionable, or it may be that it was simply a generation of really talented philosophers.

I love this book because it is again incredibly rigorous, analytic and not at all sentimental or wishy washy. It is what it says on the cover – there’s a feminist component to it, and a sceptical component to it. It came out in the late seventies, a time when people were still barred from jobs on grounds of sex. Janet makes the point – which others had made before, including John Stuart Mill – that this makes no sense. If you say no women should be bus drivers because they’re not capable enough or whatever, then you don’t need a rule that no women should be bus drivers. All you need is a rule saying that no one who isn’t capable of driving a bus should be a bus driver, which removes sex from the issue.

That’s the feminist bit. And the book is sceptical because it doesn’t take a position on some of the empirical claims about sex, such as whether men’s and women’s brains are different in any way, or whether men and women have naturally different interests or approaches. It doesn’t take any position on that, and leaves the empirical facts to be uncovered and argued about elsewhere. So she is feminist, but sceptically so.

She is also a leading thinker on bioethics. What are some of the new ethical questions which have been thrown up by scientific progress?

Janet’s most recent book is about the morality of organ donation. People die every day because there is a shortage of organs. One moral question is if we should allow people to sell their organs. Would that help to solve the shortage problem? It might not. It might be that if you put a price on it, fewer people would sell their organs – or it might be that lots of people would and you would solve the crisis. That’s the empirical problem. The philosophical dispute is whether it would be justifiable to have a trade in organs.

Somebody from the conservative wing of bioethics is Michael Sandel. He would be aghast at the commodification of certain things, including organs. But it’s difficult to figure out just why it would be wrong for you to be allowed to sell your organs. If you’re presented with all the choices, and you think this is your best choice, why should I deprive you of the opportunity of exercising your liberty? Who am I to say you can’t do what you want with your body? If you fully understand the implications, what right do I have to deny you that decision?

A couple of people in China now have sold their kidneys in order to buy iPads. From a utilitarian perspective, is that justified if your happiness from having the iPad is greater than the potential unhappiness of kidney failure and a painful death?

From a utilitarian perspective, it certainly could be. I think the reason why people recoil from that idea is because they think the person is making an empirical mistake. They think that they are falling for short termism, and will get a pleasure boost but in the long run will live to regret it. That may be true, in which case from a utilitarian point of view they are making a blunder. But perhaps they will survive to a good old age with one kidney, without noticing the absence of their other one, and get enormous pleasure from using their iPad to access Five Books.

What would you sell your kidney for? Not an entirely flippant question.

I would sell my kidney for my son’s life, or a Nobel prize.