What makes me the same person throughout my life?

January 2, 2017 9:15 AM

Philosopher Derek Parfit has died. The author of the landmark Reasons and Persons was 74. If you've never heard of Parfit, you may have heard of the Repugnant Conclusion (which highlights paradoxes in how we understand obligations to future generations). Or if you've ever mused on what would happen to you if you used a Star Trek-style transporter, you may enjoy Parfit's treatment of the philosophical implications in the teletransportation paradox. For more about Parfit, read this profile by Larissa MacFarquhar in the New Yorker.
posted by Cash4Lead (42 comments total)

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posted by Jonathan Livengood at 9:30 AM on January 2, 2017

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I guess we can't blame this on 2016.
posted by dis_integration at 9:46 AM on January 2, 2017 [3 favorites]

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posted by Token Meme at 9:54 AM on January 2, 2017

If Parfit, philosopher of the Repugnant Conclusion, had died a few hours previous, we could have blamed it on 2016. Instead, we now must consider that all years henceforth may be as bad as 2016.

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(I hadn't known of the Repugnant Conclusion prior to this post about Parfit's passing, and there's an unhappy irony in that.)
posted by notyou at 10:05 AM on January 2, 2017 [6 favorites]

Damn. I was a fan.
posted by anotherpanacea at 10:05 AM on January 2, 2017

A great loss. Parfit was the inspiration for (and namesake of) the main character in a branching-narrative video game I've been writing for a little over a year to explore the consequences of ethical choices. The intersection of the Repugnant Conclusion / Mere Addition Paradox with Utilitarianism and the "Utility Monster" idea is fascinating. Thanks for the post.

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posted by churl at 10:24 AM on January 2, 2017 [6 favorites]

If we considered my imagined cases, we would be strongly inclined to believe that our continued existence is a deep further fact, distinct from physical and psychological continuity, and a fact that must be all-or-nothing. This is not true.

Is the truth depressing? Some may find it so. But I find it liberating, and consoling. When I believed that my existence was such a further fact, I seemed imprisoned in myself. My life seemed like a glass tunnel, through which I was moving faster every year, and at the end of which there was darkness. When I changed my view, the walls of my glass tunnel disappeared. I now live in the open air. There is still a difference between my lives and the lives of other people. But the difference is less. Other people are closer. I am less concerned about the rest of my own life, and more concerned about the lives of others.

From Reasons and Persons.
posted by grobstein at 10:50 AM on January 2, 2017 [10 favorites]

Parfit's work on personal identity was what compelled me to go to grad school in philosophy. A PhD and postdoc later, I can say that was a bad decision. But the Parfitian themes of the novel I'm now writing haven't escaped me. He certainly left a mark on my life.

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posted by Beardman at 11:40 AM on January 2, 2017 [9 favorites]

I wonder if this quote seems unclear to anyone else:

“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” (Parfit 1984).

First of all, why ten billion? Does the Repugnant Conclusion not get going at smaller sizes? 9 Billion? 8? Is 1 billion people enough? I don't think that is what he means; the number must be from the context of the quote.

So he means, the existence of the 10 billion people with high quality of life means that the "much larger imaginable population" doesn't exist, although it could have existed, if the high quality of life were to be reduced so that there could be more people?

Is it really the case that adding more and more people with lives "barely worth living" increases the total good in the world? Because their lives are just over the edge of not being worth living? That's a bummer! Like if you have a little town with 500 people, doing pretty much OK, it would be better if you could have 5000 people stuffed in there, mostly miserable, but getting barely enough satisfaction to keep them going?

And how is it again that we measure quality of life, so that we can begin our utilitarian calculations? It would be a disaster to measure it wrong - then all the calculations would be no good.
posted by thelonius at 11:45 AM on January 2, 2017 [1 favorite]

Very interesting. I've always had an interest in philosophy but haven't studied it formally. The "Repugnant Conclusion" is new to me but something I'm going to read more about.

So... happy for this new avenue to explore, but also sad for the recent loss of such a thinker.

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posted by Artful Codger at 12:05 PM on January 2, 2017

For Derek Parfit, trying to be good towards people around you was not enough. His major contribution is about how to be ethical towards people we have never known and will never know, who are unrelated to us and with whom we can not in any way have any connection whatsoever. His answer was that we should still treat those people ethically.

Who among us can say that they can manage this?

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posted by Pyrogenesis at 12:12 PM on January 2, 2017 [7 favorites]

Who among us can say that they can manage this?

No one?
posted by thelonius at 12:14 PM on January 2, 2017

Of course, no one. It's not an imperative, but simply a testament to where he was willing to go.
posted by Pyrogenesis at 12:17 PM on January 2, 2017 [3 favorites]

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posted by grimmelm at 12:23 PM on January 2, 2017

The Repugnant Conclusion makes no sense to me. And I am, perhaps, not that bright. But it seems to me that the supposition that more people equals more better? meaning? I don't get it.

Like why is 10 billion people with high quality of life equal to 20 billion people with slightly less quality of life? Why is more people better?
posted by tunewell at 12:42 PM on January 2, 2017

I cackle maniacally at the Repugnant Conclusion but, that said, I'm an anti-natalist.
posted by Token Meme at 12:59 PM on January 2, 2017 [2 favorites]

Like why is 10 billion people with high quality of life equal to 20 billion people with slightly less quality of life? Why is more people better?

It's just part of the assumptions that lead to the Repugnant Conclusion. If you could quantify the quality of life of a person, then the model supposes that you could add up these quantities to find a corresponding quantity for the population. If you let yourself do that, then you get the RC. If you don't, then fine; there are a number of objections to the model giving rise to the RC (many of which are catalogued in the "Repugnant Conclusion" link).

The thought experiment is considered interesting because utilitarians often have beliefs that can be used to imply the RC.
posted by a snickering nuthatch at 1:00 PM on January 2, 2017 [3 favorites]

I would agree that the aggregate calculation of happiness isn't the right measure (although it seems to mirror real population dynamics: we are going to continue breeding until everyone has a marginal quality of life, like yeast in a barrel), but trying to think of a better one is tricky. Then again, the reason it's called "repugnant" is that there is some common, if not well-defined, frame of reference which finds it abhorrent (but presumably wouldn't find the idea of adding one more happy person to a happy population terrible).

I guess it's a kind of twin-paradox-non-paradox whereby the conclusion is unpalatable, but not necessarily false.
posted by Wrinkled Stumpskin at 1:03 PM on January 2, 2017 [3 favorites]

The point of the Repugnant Conclusion is that naïve utilitarianism takes one into intuitively unpleasant places. The point was not that we should be OK with those places, the point is that naïve utilitarianism won't get us where we want to go.
posted by PMdixon at 1:04 PM on January 2, 2017 [15 favorites]

I thought the examples offered at Plato.Stanford clarified the issue and took it beyond happiness accounting:

Parfit was led to the Repugnant Conclusion by his considerations concerning how we ought to act in cases where our decisions have an impact on who will exist in the future. Consider the following two scenarios (see Parfit 1984 chapter 16):

1. A pregnant mother suffers from an illness which, unless she undergoes a simple treatment, will cause her child to suffer a permanent handicap. If she receives the treatment and is cured her child will be perfectly normal.
2. A woman suffers from an illness which means that, if she gets pregnant now, her child will suffer from a permanent handicap. If she postpones her pregnancy a few months until she has recovered, her child will be perfectly normal.

What ought the women to do in the two cases? In case (1) the obvious answer is that the mother ought to undergo the treatment since her actual child will thereby get a better life. However, it is problematic to appeal to this kind of reason when we turn to case (2). If the woman postpones her pregnancy, then the child that is brought into existence will not be identical to the child she would have had, had she decided to become pregnant while she was ill (it will not be the same ovum and sperm that meet). Hence, the alternative for the child brought into existence during the mother's illness is non-existence, and to claim that it would have been better for this child if the mother had postponed pregnancy is tantamount to claiming that non-existence would have been better for her. Assuming that the child has a life worth living, this seems wrong if not nonsensical (for a discussion, see Narveson 1967, Parfit 1984, appendix G; Bykvist 2007; Arrhenius 2009a; McMahan 1981, 2009; Rabinowicz 2009).

posted by notyou at 1:09 PM on January 2, 2017 [5 favorites]

The point of the Repugnant Conclusion is that naïve utilitarianism takes one into intuitively unpleasant places. The point was not that we should be OK with those places, the point is that naïve utilitarianism won't get us where we want to go.

Gotcha. Now I understand- it's a critique of the whole way of thinking that leads to that path.
posted by tunewell at 1:10 PM on January 2, 2017 [1 favorite]

Assuming that the child has a life worth living, this seems wrong if not nonsensical

But why would you assume that?
posted by rue72 at 1:17 PM on January 2, 2017 [1 favorite]

Why would you choose the existence of the child the mother would have if she rushed to get pregnant over the existence of the child the mother would have had if she waited to get pregnant?

Sorry, I don't mean to go off on a random tangent. I'm just not understanding what the philosophical dilemma is in either one of those two scenarios.
posted by rue72 at 1:21 PM on January 2, 2017

Jpfed: It's more a matter of optimized resources. Within a populated area of one hundred thousand people, (in Western Civilization, circa 2017), you'd have a number of those persons traveling on asphalt roads in cars and trucks, many of which often end up leaking oil, battery acid and fuel onto the roads and nearby sediment. Out of that number, there would be a number of hybrid and alternate-powered vehicles that would be more efficient, but not enough to make up the total difference.

In retrospect, those figures are still preferable to the routine of half a -million drivers and passengers during the late 1960's-1970's, who were mostly bound to road transportation powered by leaded gas. At that time, sure, there'd be some experimental electrics and diesel vehicles, but the return yield (and health benefits) would be much lower.

Compare that still to one million
road-farers at the beginning of the Industrial Revolution; beyond a few horseless carriages and electrically-powered trolley cars, a good number of riders and drivers were dependent on animals and wagons. At that time, conditions were such that the livestock (including horse, mule and even dog-powered carts) could suffer mishaps, or be underfed due to economic conditions/time constraints, or even get sick from poor care...to say nothing of the carts, which were sometimes re-fashioned from parts of older wooden frames and components and were not subject to safety regulations, insurance, nor necessarily any manufacturer's warranty at the time.

On the whole, some march forward upon the blood and sweat of others' expense. Given the objective of aspiring for something better, life needs not to continue to be trenchant nor insensitive, but Parfit is observing that there are somber costs to complacency and progress which - individually and on the whole - the world too often tends to overlook.
posted by Smart Dalek at 1:25 PM on January 2, 2017 [2 favorites]

Gotcha. Now I understand- it's a critique of the whole way of thinking that leads to that path.

I think the thing that makes this a hard challenge to answer is that many of the alternative assumptions one could make to avoid the issue - for example using "average happiness" as your yardstick - also lead to arguably unpleasant conclusions.
posted by atoxyl at 1:27 PM on January 2, 2017 [5 favorites]

[Sorry about the rough math edits: I should've previewed more before posting.]
posted by Smart Dalek at 1:31 PM on January 2, 2017

Hence, the alternative for the child brought into existence during the mother's illness is non-existence, and to claim that it would have been better for this child if the mother had postponed pregnancy is tantamount to claiming that non-existence would have been better for her. Assuming that the child has a life worth living, this seems wrong if not nonsensical

I have to wonder about that last assumption. Perhaps now Parfit doesn't feel the quite same way about non-existence.
posted by gusottertrout at 1:37 PM on January 2, 2017 [4 favorites]

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He was one of the greats. I will always regret not taking a class with him when I had the chance.
posted by cosmic owl at 1:51 PM on January 2, 2017

Why would you choose the existence of the child the mother would have if she rushed to get pregnant over the existence of the child the mother would have had if she waited to get pregnant?

My initial reading of that was that it was a choice between being able to have both children or just one, which is straightforward enough as an argument. But it does say "a few months" and if that means here what it means to me I'm not sure I quite get it either? Because in that case - granting the other premises - it seems like you are judging the value of the life of one possible child over the other, and while there's an argument that this can't or shouldn't be done it seems like the scenario assumes it can be from the beginning.

Does anybody have a clearer interpretation? (okay I'm sure there's one to be found online)
posted by atoxyl at 1:53 PM on January 2, 2017

The point of the Repugnant Conclusion is that naïve utilitarianism takes one into intuitively unpleasant places.

If moral philosophy is correct when it delivers conclusions that agree with our moral intuitions, and suspect when it does not, then what's the point of it really if it doesn't have any normative force? If our moral intuitions have precedence then why not just rely on them directly? Perhaps you could say that moral philosophy at least systematizes our intuitions and forces us to be logically consistent, but it's a logical consistency in a backwards direction: starting from a set of "intuitively" acceptable conclusions and reasoning backwards to a set of rationalizations.

By using their intuition to sanity check their arguments, moral philosophers end up with theories that are models of our intuitions. But then, wouldn't studying the moral intuitions of humans be psychology instead? And can they ever come up with counter-intuitive results that we are nevertheless forced to accept, the way mathematicians or physicists can? If moral questions are really just questions about human psychology, we shouldn't be surprised if human intuition yields contradictory, vague or arbitrary conclusions. The answer to the Repugnant Conclusion is probably just that people feel more people is better, up to a certain point at which it isn't, and it depends on social dynamics, resource scarcity and a bunch of other stuff.
posted by L.P. Hatecraft at 2:20 PM on January 2, 2017 [5 favorites]

Perhaps now Parfit doesn't feel the quite same way about non-existence.

He discusses this some in the NY-er piece:

It seems to a friend of Parfit’s that his theory of personal identity is motivated by an extreme fear of death. But Parfit doesn’t believe that he once feared death more than other people, and now he thinks he fears it less.

'My death will break the more direct relations between my present experiences and future experiences, but it will not break various other relations.'

Some people will remember him. Others may be influenced by his writing, or act upon his advice. Memories that connect with his memories, thoughts that connect with his thoughts, actions taken that connect with his intentions, will persist after he is gone, just inside different bodies.

'This is all there is to the fact that there will be no one living who will be me. Now that I have seen this, my death seems to me less bad.'


posted by thelonius at 2:20 PM on January 2, 2017 [7 favorites]

I have to wonder about that last assumption. Perhaps now Parfit doesn't feel the quite same way about non-existence.

I don't really get why people think now is a worse time to have children than most other historical eras. For much of history, any children I had might have had a 50% chance of dying before age 5. If an epidemic came through, I might lose more of my children within a short time of each other. Unless we were among an extremely small privileged class, my kids would be able to expect a life of illiteracy and unremitting hard labor, eating food of indifferent quality with little variation, with little privacy, rest, or comfort. They would live, too, with the possibility of my own demise, which might plunge them further into poverty or send them to the workhouse. The value of human life would be held so lightly, and the bonds of social control so tightly, that children of 8 could be hanged in public for stealing bread.

I think the question underneath the pregnancy thing, and also my impatience with people who say, "Oh, how can we bring children into such a world?" is the idea that some life is almost certainly better than no life. So, when the woman who might get pregnant this month defers it to undergo medical treatment, the specific child she would have borne loses its chance at life completely. That benefit is incurred by a completely different person who is born at some point down the line. It's a tricky and perhaps foolish argument, because every month millions of possible human beings are not conceived.

The idea, though (and I have only read more at the links, not had any prior knowledge, so could be very wrong) is that, if you take an additive view of human good—that the goodness of all the lives of all the people alive can be added together—you can end up with the idea that a whole bunch of lives that are not very good at all is worth more than fewer lives of a higher quality. Like a billion people with a "life goodness value" of 1 create in some way a higher degree of happiness than a million people who each have a life goodness value of 3. I think this is what is being referred to as the Repugnant Conclusion, a sort of inevitable end product of utilitarian thinking where you end up with the idea that it is better for more people to be alive and miserable than for fewer to be alive and content.

One of the links in the post goes on to talk about various ways to deal with the Repugnant Conclusions, such as averaging the happiness rather than imagining it to be purely additive, and so on. But nobody is suggesting that it really is better for a lot of people to live bad lives. On the contrary, they seem to be working on ways to avoid that conclusion.

As far as having children in the world we live in today goes, I dread thinking of my children suffering. All parents, I suppose, do. But how much suffering in one life offsets the goodness of it? I have four children, ages 22 to 9 (two of them adopted, in case any of you zero population growth types are thinking about jumping down my throat), and they have led good lives. Friends of mine have a baby who will turn one in a few days. He has had a terrific single year of life, during which he has made his parents and the many people who love them and also dote on the baby, happier than they were before he was born.

I think it's a kind of gamble: will they have enough years of goodness before the catastrophe, whatever that is? But that is always the gamble with children. Will they be healthy? Will they die in an accident, or of cancer? Will they suffer (and perhaps die) of drug addiction? Will a disability come upon them in adolescence? I am a chronic pain sufferer, and have not had more than a half-dozen days over more than 20 years when I could be said to be pain free. It will not be long now until I will have been in constant pain for over half my life. For nearly three years now, my pain has been severe on a daily basis. Was my life a mistake?

I will be very sorry if my children or grandchildren or great-grandchildren outlive civilization due to global warming or some other catastrophe. But I will be very happy if, until that happens, they are able to do and have some of the things that make life worthwhile for ourselves and for the others we know and care for.
posted by Orlop at 2:23 PM on January 2, 2017 [6 favorites]

I don't really get why people think now is a worse time to have children than most other historical eras.

That wasn't the intended reading of my brief note, more the suggestion that non-existence is a concept which we come to with the unavoidable bias of existing, and thus tending to favor that state. In a non-existent state, one's conclusions on the relative merits of each would be unavoidably different, so, in a way, only now might Parfit approach the subject from each side. (Though, yes, non-existence in the sense of never had versus no longer can be understood differently.)
posted by gusottertrout at 2:38 PM on January 2, 2017

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posted by LobsterMitten at 3:41 PM on January 2, 2017

Thank you for this post, Cash4Lead. After reading the article on the Repugnant Conclusion, especially answer 2.4, and following a few Wikipedia links, I can now say with certainty that I am a negative utilitarianist. Bring on the benevolent world-exploder, please, before it's too late.
posted by Faint of Butt at 4:02 PM on January 2, 2017 [2 favorites]

This is sad. I studied R+P in my very first metaphysics class as an undergrad. I now work in that area professionally. He was a giant, and will be missed.

I was about to say that he wasn't a huge influence on my own work. But in this way I think he was: He made very clear the importance and use of thought experiments in a priori reasoning. Obviously he wasn't the first to use them, or cause people to think about them. But at least in my own case he forced me to think about the epistemology involved with philosophical claims, and the relevance of thought experiments therein.
posted by persona au gratin at 5:31 PM on January 2, 2017 [1 favorite]

One other thing. Lots of smart younger people in philosophy today are working on refinements of very specific issues. They are very good technical philosophers and good at working out the minute details of analyses and the like. Then there are other philosophers who are good at big-picture stuff, drawing connections between disparate fields and causing people to think about things in new ways. Parfit was in this second category. As was Hilary Putnam, who died a few months ago.
posted by persona au gratin at 5:47 PM on January 2, 2017 [1 favorite]

If moral philosophy is correct when it delivers conclusions that agree with our moral intuitions, and suspect when it does not, then what's the point of it really if it doesn't have any normative force? If our moral intuitions have precedence then why not just rely on them directly?

There's the possibility that there are situations for which moral philosophy could provide an answer but moral intuition does not. If there were such situations, a moral philosophy that (as smoothly as possible) extends moral intuition while agreeing with it in their common domain could be viewed as a generalization of moral intuition.
posted by a snickering nuthatch at 6:10 PM on January 2, 2017 [6 favorites]

Is it really the case that adding more and more people with lives "barely worth living" increases the total good in the world?

I don't think so, no.

There's maybe a good Ted Chiang-ish story in there somewhere, starting from the premise that a single, perfectly happy God of an empty universe is morally equivalent to a universe containing an infinite number of souls in infinite agony, since none of the infinite souls has the zero value of happiness of non-existence.
posted by Jon Mitchell at 7:21 PM on January 2, 2017 [1 favorite]

Does anybody have a clearer interpretation?

The point of the exercise is exactly to draw out this problem in moral reasoning concerning persons not yet in existence, and in particular who may or may not exist; the first scenario is meant to give us a scenario in which something like cost benefit analysis (small cost, high benefit) suffices - because the child born healthy is the same as the child who would not be. The second scenario is intended to superficially resemble the first, but we can't use the same reasoning to reach an analogous conclusion because the effects of the woman's decision are on different people. We're choosing which person will exist, not choosing which outcome a specific person will experience. I'm sure disability studies scholarship has much to say on this.

(Personally I think "ought implies can" cuts through most but not all of the "what duties do we owe to people who don't-but-could exist?" questions.)
posted by PMdixon at 7:31 PM on January 2, 2017

If there were such situations, a moral philosophy that (as smoothly as possible) extends moral intuition while agreeing with it in their common domain could be viewed as a generalization of moral intuition

Additionally, it is possible (and certainly seems to be the case) that our moral intuitions are inconsistent as a whole. By identifying such inconsistencies it's possible to prioritize among the competing factors. (I think it is generally an uncontroversial statement that a good system of morals should not both compel and forbid the same act.)
posted by PMdixon at 7:35 PM on January 2, 2017 [1 favorite]

This IEP article on personal identity may also be helpful.
posted by studio2054 at 10:59 AM on January 15, 2017