Here's his 2008 paper, "Life Extension versus Replacement," which explores an amendment to utilitarianism that would allow us to prefer Life Extension
I feel like the thing that should allow us to prefer life extension is the thing that makes people search for amendments to utilitarianism that would allow us to prefer life extension.
I'm not comfortable spending my time and mental resources on these utilitarian puzzles until I am shown a method (or even a good reason to believe there is such a method) for interpersonal utility comparison. If such a method has already been discussed on Less Wrong, I would appreciate a link to it. Otherwise, why engage in metaphysical speculation of this kind?
As a first rough approximation, one could compare fMRIs of people's pleasure or pain centers.
Hedons are not utilons. If they were, wireheading (or entering the experience machine) would be utility-maximizing.
A currently living person doesn't want to die, but a potentially living person doesn't yet want to live, so there's an asymmetry between the two scenarios.
I am an average utilitarian with one modification: Once a person exists, they are always counted in the number of people I average over, even if they're dead. For instance, a world where 10 people are born and each gets 50 utility has 10X50/10=50 utility. A world where 20 people are born, then 10 of them die and the rest get 50 utility each has (10X50+10X0)/20=25 utility. AFAICT, this method has several advantages:
This doesn't seem to be monotonic in pareto improvements.
Suppose I had the choice between someone popping into existence for 10 years on a distant planet, living a worthwhile life, and then disappearing. They would prefer this to happen, and so might everyone else in the universe; however, if other's utilities were sufficiently high, this person's existence might lower the average utility of the world.
This actually reminds me of a movie trailer I saw the other day, for a movie called In Time. (Note: I am not at all endorsing it or saying you should see it. Apparently, it sucks! lol)
General premise of the sci-fi world- People live normally until 25. Then you stop aging and get a glowy little clock on your arm, that counts down how much time you have left to live. "Time" is pretty much their version of money. You work for time. You trade time for goods, etc. Rich people live forever; Poor people die very young. (pretty much imagine if over-drafting your bank account once means that you die)
Anyway, when I saw this preview, being the geek I am, I thought: "That doesn't make sense!"
The reason it doesn't make sense has to do with the extension v. replacement argument. Until the age of at least 16, and more generally 22-ish, people are a drain rather than benefit to society. The economic cost of maintaining a child is not equal to the output of a child. (I'm obviously not talking about love, and fulfillment of the parents, etc.).
This society's idea is that people of working age would be required to provide the economic cost for their life. However what would act...
response a) My life gets better with each year I live. I learn new things and make new friends. 2 people who live 12 years will not have the same amount of happiness as I will on my birthday, when I turn 24. I see no reason why the same should not hold for even longer lifespans.
Response b) I privilege people that already exist over people who do not exist. A person living 800 years is more valuable to me EVEN if you say the same amount of happiness happens in both cases. I care about existing people being happy, and about not creating sad people, but I don't particularly care about creating new happy entities unless it's necessary for the perpetuation of humanity, which is something I value.
response c) The personal response, I value my own happiness significantly higher than that of other people. 1 year of my own life is worth more to me than 1 year of someone else's life. If my decision was between creating 10 people as happy as I am or making myself 10 times happier, I will make myself 10 times happier.
Finally, you don't seem to realize what is meant by caring about average utility. In your scenario, the TOTAL years lived remains the same in both cases, but the AVERAGE utility goes far down in the second case. 80 years per person is a lot less than 800 years per person.
First thought: I accept the repugnant conclusion because I am a hard utilitarian. I also take the deals in the lifespan dilemma because my intuition that the epsilon chances of survival "wouldn't be worth it" are due to scope insensitivity.
Second: I attach much more disutility to death than utility to birth for two reasons, one good and bad. The bad reason is that I selfishly do not want to die. The good reason, which I have not seen mentioned, is that the past is not likely to repeat itself. Memories of the past have utility in themselves! History is just lines on paper, sometimes with videos, sometimes not, but it doesn't compare to actual experience! Experience and memory matter. Discounting them is an error in utilitarian reasoning.
I'm perfectly prepared to bite this bullet. Extending the life of an existing person a hundred years and creating a new person who will live for a hundred years are both good deeds, they create approximately equal amounts of utility and I believe we should try to do both.
I already exist. I prefer to adopt a ruleset that will favor me continuing to existing. Adopting a theory that does not put disutility on me being replaced with a different human would be very disingenuous of me. Advocating the creation of an authority that does not put disutility on me being replaced with a different human would also be disingenuous.
For spreading your moral theory, you need the support of people who live, not people who may live. Thus, your moral theory must favor their interests.
[edit] Is this metautilitarianism?
In the replicating scenario, people die twice as much. Since expectations of near death are unpleasant and death itself is unpleasant for the relatives and friends, doubling the number of deaths induces additional disutility, ceteris paribus.
I don't see how this is a paradox at all.
Scenario (1) creates 100 years of utility, minus the death of one person. Scenario (2) creates 100 years of utility, plus the birth of one person, minus the death of two people. We can set them equal to each other and solve for the variables, you should prefer scenario (1) to scenario (2) iff the negative utility caused by a death is greater than the utility caused by a birth. Imagine that a child was born, and then immediately died ten minutes later. Is this a net positive or negative utility? I vote negative ...
I prefer 1 to 2 because I'm currently alive, and so 1 has a more direct benefit for me than 2. I don't know if I have any stronger reasons; I don't think I need any, though.
I think it comes down to how you value relationships. I don't want my family replaced, so replacing one of them with someone in a similarly valuable mental state might be equal in terms of their mental state, but because you've broken a relationship I value, the total utility has dropped. Other than this, I'm not sure I can see a relevant difference between extension and replacement.
I assume everyone is familiar with the following argument:
Premise: You are not indifferent about the utility of people who will come to exist, if they definitely will exist. Conclusion: You can't be in general indifferent between people existing and not existing.
World A: Person has 10 utility World B: Person does not exist World C: Person has 20 utility
By hypothesis, you're not indifferent between A and C. Hence by transitivity, you're not indifferent between both A,B and B,C.
Ignoring the fact that replacement tend to be expensive, I'd consider them equal utility if I believed in personal identity. I don't, so not only are the equally good, they are, for all intents and purposes, the same choice.
I guess that my own response to the repugnant conclusion tends to be along the lines that mere duplication does not add value, and the more people there are, the closer the inevitable redundancy will bring you to essentially adding duplicates of people you already have. At least as things are at present, giving an existing person an extra hundred years seems like it will involve less redundancy than adding yet another person with a hundred year lifespan to the many we already have and are constantly adding.
We can deal with this with a thought experiment that engages our intuitions more clearly, since it doesn't involve futuristic technology: Is it okay to kill a fifteen year old person who is destined to live a good life if doing so will allow you to replace them with someone who will live a life that is as good, or better, as the fifteen year old's remaining years would have been? What if the fifteen year old in question is disabled, so their life is a little more difficult, but still worth living, while their replacement would be an able person? Would i...
This is a really interesting issue which I suspect will only get more important over time. I largely agree with Xachariah, but I see a greater dependency on personal preference.
Another way of looking at the problem is to consider individual preferences. Imagine a radical sustainable future where everyone gets to choose between an extended life with no children or a normal life with 1 child (or 2 per couple). I'd be really interested in polls on that choice. Personally I'd choose extension over children. I also suspect that polls may reveal a significa...
As you phrased it, life extension and replacement seem roughly similar to me. I don't feel the need to modify my utilitarianism to strongly prefer life extension. There are some differences, though:
This presumes that extending the life of an existing person by 100 years precludes the creation of a new person with a lifespan of 100 years. We will be motivated to prefer the former scenario because it is difficult for us to feel its relevance to the latter.
I currently route around this by being an ethical egoist, though I admit that I still have a lot to learn when it comes to metaethics. (And I 'm not just leaving it at "I still have a lot to learn", either - I'm taking active steps to learn more, and I'm not just signalling that, and I'm not just signalling that I'm not signalling that, etc.)!
But in my thought experiment, average utility remains unchanged.
The average utility, counting only those two people, is unchanged (as long as we assume that life from 0-100 is as pleasurable as life from 100-200). But firstly the utility of other humans should be taken into account; the loved ones of the person already living, the likely pleasure given to others by younger people in comparison to older people, the expected resources consumed etc.
But perhaps your thought experiment supposes that these expected utility calculations all happen to be equal ...
Has anyone here ever addressed the question of why we should prefer
(1) Life Extension: Extend the life of an existing person 100 years
to
(2) Replacement: Create a new person who will live for 100 years?
I've seen some discussion of how the utility of potential people fits into a utilitarian calculus. Eliezer has raised the Repugnant Conclusion, in which 1,000,000 people who each have 1 util is preferable to 1,000 people who each have 100 utils. He rejected it, he said, because he's an average utilitarian.
Fine. But in my thought experiment, average utility remains unchanged. So an average utilitarian should be indifferent between Life Extension and Replacement, right? Or is the harm done by depriving an existing person of life greater in magnitude than the benefit of creating a new life of equivalent utility? If so, why?
Or is the transhumanist indifferent between Life Extension and Replacement, but feels that his efforts towards radical life extension have a much greater expected value than trying to increase the birth rate?
(EDITED to make the thought experiment cleaner. Originally the options were: (1) Life Extension: Extend the life of an existing person for 800 years, and (2) Replacement: Create 10 new people who will each live for 80 years. But that version didn't maintain equal average utility.)
*Optional addendum: Gustaf Arrhenius is a philosopher who has written a lot about this subject; I found him via this comment by utilitymonster. Here's his 2008 paper, "Life Extension versus Replacement," which explores an amendment to utilitarianism that would allow us to prefer Life Extension. Essentially, we begin by comparing potential outcomes according to overall utility, as usual, but we then penalize outcomes if they make any existing people worse off.
So even though the overall utility of Life Extension is the same as Replacement, the latter is worse, because the existing person is worse off than he would have been in Life Extension. By contrast, the potential new person is not worse off in Life Extension, because in that scenario he doesn't exist, and non-existent people can't be harmed. Arrhenius goes through a whole list of problems with this moral theory, however, and by the end of the paper we aren't left with anything workable that would prioritize Life Extension over Replacement.