Philosophy Phridays – The Repugnant Conclusion

Philosophy Phridays is a series where each Friday, I go to the Stanford Encyclopedia of Philosophy, click on “random entry,” and then write about whatever comes up. This week’s random entry is the Repugnant Conclusion.

Today’s topic is from the realm of population ethics. Population ethics poses questions such as, “Should we procreate?” “Is there a moral obligation to have children?” and “Can the population get too big?” It is currently a hot topic in philosophy and proves false the notion that all philosophers deal with problems that are thousands of years old.

The Repugnant Conclusion was formulated by Derek Parfit in 1984. He said, “For any possible population of at least ten billion people, all with a very high quality of life, there must be some much larger imaginable population whose existence, if other things are equal, would be better even though its members have lives that are barely worth living.” Intuitively, this is a hard pill to swallow, the idea that a huge population with lives that are barely worth living is better than a small population where everyone is blissful. So, how does he get there?

The answer is simple, Utilitarianism. Take a look at this chart:

Figure 2

The height of the rectangles corresponds to the level of welfare of the population while the width is how big the population is. You can think of the area of each box as the total welfare. Which is the best? A has a very high level of welfare, but A+ has just as many people at that level of welfare plus another group of people at a lower, but still positive, level of welfare. So, most people would say that A+ is better than A because there is more total welfare. But B has the same number of people as A+, and they are all a bit happier than the lower tier in A+, but not quite as happy as the upper tier. Most people would say that B is better than A+, again more total welfare. And if B is better than A+, and A+ is better than A, B is better than A. This can be continued forever where each new, larger, not quite as happy population is better than the happier, but smaller, populations because the larger populations have more total welfare.

It is called the Repugnant Conclusion because almost no one likes the conclusion, but it is very hard (some say impossible) to escape from it. My instinct, and others have had this thought, is that the Repugnant Conclusion isn’t something we should follow. Rather it shows a failure of Utilitarianism, kind of like trolley problems. There must be more to consider than just adding up welfare. But defenders of the Repugnant Conclusion can control for these other factors. If A, A+, and B are all equally free or just or egalitarian or loving or anything else you can think to put in there, the only difference is the total welfare, wouldn’t we want to maximize that welfare?

In the 35 years since Parfit raised the problem, philosophers have been trying to solve it. There are eight general approaches that have become popular.

The first approach is to change the way we measure value in regards to welfare and a life worth living. One way of doing this is to rank populations by average welfare rather than total welfare. This does solve the problem as A is the best population. But it introduces a lot of other problems. For instance, a society where most people are miserable, but there are a few people that are so happy it raises the average above a society where everyone is moderately happy. Do we really want to say the society with a majority of miserable people is better? Another way to change the measure is to say that the value of each additional life decreases with the increase in population. This leads to some absurd conclusions, though, as if there is some limit to how much welfare a population can have. Where is that limit? And how do you tell the next person on the list that they’re one too many?

The second approach is to assume that not all welfare is equal. This basically imagines that there are higher goods and lower goods. Think of J.S. Mill’s famous line about preferring to be Socrates dissatisfied than a pig satisfied. Population A from above enjoys all the finer things in life, while population B has fewer finer things, and so on down the line. It can be reasoned from this that population A is better than B. But it’s all very arbitrary. Who decides what’s a higher good or a lower good? And why do you lose higher goods as the population grows?

The third approach is to count welfare differently depending on temporal or modal considerations. This basically means to count actual people more than hypothetical people or to give the present more weight than the future. This could work to avoid the Repugnant Conclusion, but again, it creates new problems. For instance, on this view we have no reason to combat climate change since doing so would lower our current welfare and that matters more than any future welfare. There’s really no planning in this scenario.

The fourth approach is to completely change the way we look at a life worth living. There is a pessimistic point of view, going back to at least Schopenhauer in the West, that says that no life can build positive welfare. The best we can do is satisfy wants, but that doesn’t improve us. So the best we can hope for is a life of neutrality. Realistically, though, some wants will always be unfulfilled, causing well being to go negative. In this view, not being born is actually preferable to being born into a life of suffering. If not being born is preferable, then adding population does not lead to more welfare. That takes care of the Repugnant Conclusion, but it means we are stuck living lives that aren’t worth living.

The fifth approach is to reject transitivity. Transitivity is the logical operation whereby if p is better than q, and q is better than r, then p is better than r. I’m not qualified as a logician to say how such a basic principal can be dropped, but if it could, population A+ could be better than A, and B could be better than A+, but A could be better than B. The problem with this is that without transitivity, there is no logically sound way to choose one thing over another. That conclusion seems pretty repugnant to me.

The sixth approach is to appeal to other values. For instance, it’s not just the total amount of welfare, it’s the level of welfare for each person compared to the level of welfare that person deserves. This runs into the same problems as the second approach. Plus, and this is a not in the article, I believe that the idea of anyone deserving anything just by virtue of existence is absurd. So I would ask the question how these people come to deserve their level of welfare. Another value that is suggested is the Maximin principal. For those who haven’t read Rawls, that means in a society, the goal should be to maximize the minimum level of welfare. That would disrupt the Repugnant Conclusion, more people at a lower level can’t be better than fewer people at a higher level. The problem with Maximin is that the tiniest gain by someone in the lower level trumps even a huge loss by someone, or many people, in the higher level. It’s putting egalitarianism before justice.

The seventh approach is to “accept the impossibility of a satisfactory population ethics.” Parfit believes that a satisfactory population ethics is possible, but some disagree. I fall into this category. Generally, philosophers don’t like the idea of a problem that can’t be answered. I feel this one is impossible for two reasons. One, as I mentioned above, Utilitarianism is the wrong tool for the job. Utilitarianism only works when you can weigh the consequences of an action. There is no way to know the consequences of an individual birth, let alone the consequences of billions of births. Two is that the whole concept of welfare and a life worth living are too vague. There’s a lot of evidence from the assisted-suicide debate that there is often a gap between what the friends and family of the would be suicide believe is a life worth living and what the person herself believes. There is no “view from nowhere” for an impartial answer.

The eighth approach is simply to accept the Repugnant Conclusion. This means accepting that a huge population with a low level of welfare actually is better than a small population with a high level of welfare. People who think we should accept it generally think that our intuitions are wrong. They say that our intuitions are from a misguided picture of what it would be like to live in the huge population. Even if it’s just barely a life worth living, it is still a life worth living, so it can’t be that bad. It still doesn’t sound good to me.

That’s about it for the Repugnant Conclusion. I do have to say, though, that I like that phrase, “Repugnant Conclusion.” I almost think it’s too bad it got used to describe a situation in population ethics. Philosophers have been coming up with repugnant conclusions forever. Just think of Plato’s forcing children to be separated from their families or Calvinist predetermination. It’s weird that it took until the 1980s for someone to coin the phrase.

Arrhenius, Gustaf, Ryberg, Jesper and Tännsjö, Torbjörn, “The Repugnant Conclusion”, The Stanford Encyclopedia of Philosophy (Spring 2017 Edition), Edward N. Zalta (ed.), URL = <>.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.