# Multiverse-Wide Preference Utilitarianism

Summary
-------

Some preference utilitarians care about satisfaction of preferences even when the organism with the preference doesn't know that it has been satisfied. These preference utilitarians should care to some degree about the preferences that people in other branches of our multiverse have regarding our own world, as well as the preferences of aliens regarding our world. In general, this suggests that we should give relatively more weight to tastes and values that we expect to be more universal among civilizations across the multiverse. This consideration is strongest in the case of aesthetic preferences about inanimate objects and is weaker for preferences about organisms that themselves have experiences.

* * *

Introduction
------------

Classical utilitarianism aims to maximize the balance of happiness over suffering for all organisms. [Preference utilitarianism](http://www.utilitarian-essays.com/hedonistic-vs-preference.html) focuses on fulfillment vs. frustration of preferences, rather than just at hedonic experiences. So, for example, if someone has a preference for his house to go to his granddaughter after his death, then it would frustrate his preference if it instead went to his grandson, even though he wouldn't be around to experience negative emotions due to his preference being thwarted.

Non-hedonic preferences
-----------------------

In practice, most of people's preferences concern their own hedonic wellbeing. Some also concern the wellbeing of their children and friends, although often these preferences are manifested through direct happiness or suffering in oneself (e.g., being on the edge of your seat with anxiety when your 14-year-old daughter hasn't come home by midnight).

However, some preferences are beyond hedonic experience by oneself. This is true of preferences about how the world will be after one dies, or whether the money you donated to that charity _actually_ gets used well even if you wouldn't find out either way. It's true of many moral convictions. For instance, I want to actually reduce expected suffering rather than hook up to a machine that makes me think I reduced expected suffering and then blisses me out for the rest of my life. It's also true of some aesthetic preferences, such as the view that it would be good for art, music, and knowledge to exist even if no one was around to experience them.

Certainly these non-hedonic preferences have hedonic effects. If I learned that I was going to be hooked up to a machine that would erase my moral convictions and bliss me out for the rest of my life, I would feel upset in the short run. However, almost certainly this aversive feeling would be outweighed by my pleasure and lack of suffering in the long run. So my preference conflicts with egoistic hedonism in this case. (My preference not to be blissed out _is_ consistent with hedonistic _utilitarianism_, rather than hedonistic _egoism_, but hedonistic utilitarianism is a kind of moral system that exists outside the realm of hedonic preferences of an individual organism.)

Because preference utilitarians believe that preference violations can be harmful even if they aren't accompanied by negative hedonic experience, there are some cases in which doing something that other people disapprove of is bad even if they never find out. For example, Muslims strongly oppose defacing the Quran. This means that, barring countervailing factors, it would be prima facie bad to deface a Quran in the privacy of your own home even if no one else knew about it.

Tyranny of the majority?
------------------------

People sometimes object to utilitarianism on the grounds that it might allow for tyranny of the majority. This seems especially possible for preference utilitarianism, when considering preferences regarding the external world that don't directly affect a person's hedonic experience. For example, one might fear that if large numbers of people have a preference against gay sex, then even if these people are not emotionally affected by what goes on in the privacy of others' bedrooms, their preference against those private acts might still matter appreciably.

As a preliminary comment, I should point out that preference utilitarianism typically optimizes _idealized_ preferences rather than _actual_ preferences. What's important is not what you think you want but what you would actually want if you were better informed, had greater philosophical reflectiveness, etc. While there are strong ostensible preferences against gay sex in the world, it's less clear that there are strong idealized preferences against it. It's plausible that many gay opponents would come to see that (safe) gay sex is actually a positive expression of pleasure and love rather than something vile.

But let's ignore this for the moment and suppose that most people really did have idealized preferences against gay sex. In fact, let's suppose the world consists of N+2 people, two of whom are gay and would prefer to have sex with each other, and the other N of whom have idealized preferences opposing gay sex. If N is very large, do we have tyranny of the majority, according to which it's bad for the two gays to have sex?

This is a complicated question that involves more subtlety than it may seem. Even if the direct preference summation came out against gay sex, it might still be better to allow it for other reasons. For instance, maybe at a meta level, a more libertarian stance on social issues tends to produce better outcomes in the long run. Maybe allowing gay sex increases people's tolerance, leading to a more positive society in the future. And so on. But for now let's consider just the direct preference summation: Does the balance of opposition to gay sex exceed the welfare of the gay individuals themselves?

This answer isn't clear, and it depends how you weigh the different preferences. Intuitively it seems obvious that for large enough N, N people opposed to gay sex can trump two people who prefer it. On the other hand, that's less clear if we look at the matter from the perspective of scaled utility functions.

*   Suppose unrealistically that the only thing the N anti-gay people care about is preventing gay sex. In particular, they're expected-gay-sex minimizers, who consider each act of gay sex as bad as another and aim to minimize the total amount that happens. The best possible world (normalized utility = 1) is one where no gay sex happens. The worst possible world (normalized utility = 0) is one where all N+2 people have gay sex. The world where just the two gay people have gay sex is almost as good as the best possible world. In particular, its normalized utility is N/(N+2). Thus, if gay sex happens, each anti-gay person only loses 2/(N+2) utility. Aggregated over all N anti-gay people, this is a loss of 2N/(N+2).
*   Also unrealistically, suppose that the only thing the two gay people care about is having gay sex. Their normalized utility for having sex is 1 and for not having it is 0. Aggregated over the two of them, the total gain from having sex is 2.
*   Because 2 > 2N/(N+2), it's overall better in direct preference summation for the gay sex to happen as long as we weight each person's normalized utility equally. This is true regardless of N.

That said, if the anti-gay people had diminishing marginal disutility for additional acts of gay sex, this conclusion would probably flip around.

It feels intuitively suspicious to just sum normalized utility. As an example, consider a Beethoven utility monster -- a person whose only goal in life is to hear Beethoven's Ninth Symphony. This person has no other desires, and if he doesn't hear Beethoven's Ninth, it's as good as being dead. Meanwhile, other people also want to hear Beethoven's Ninth, but their desire for it is just a tiny fraction of what they care about. In particular, they value not dying and being able to live the rest of their lives 99,999 times as much as hearing Beethoven's Ninth.

*   Each normal person's normalized utility without hearing the symphony is 0.99999. Hearing the symphony would make it 1.00000.
*   The Beethoven utility monster would be at 0 without hearing the symphony and 1 hearing it.
*   Thus, if we directly sum normalized utilities, it's better for the Beethoven utility monster to hear the symphony than for 99,999 regular people to do the same.

This seems suspicious. Maybe it's because our intuitions are not well adapted to thinking about organisms with really different utility functions from ours, and if we interacted with them more -- seeing them struggle endlessly, risking life and limb for the symphony they so desire -- we would begin to feel differently. Another problem is that an organism's utility counts for less as soon as the range of its experience increases. If the Beethoven monster were transformed to want to hear Beethoven's Ninth _and_ Eighth symphonies each with equal strength, suddenly the value of its hearing the Ninth alone is cut in half. Again, maybe this is plausible, but it's not clear. I think some people have the intuition that an organism with a broader range of possible joys counts more than one with fewer, though I'm not sure I agree with this.

So the question of tyranny remains indeterminate. It depends on how you weigh different preferences. However, it remains the case that it may be instrumentally valuable to preserve norms of individual autonomy in order to produce better societies in the long run.

Preferences across worlds: A story of art maximizers
----------------------------------------------------

Consider the following (highly unrealistic) story. It's the year 2100. A group of three artist couples is traveling on the first manned voyage to Mars. These couples value art for art's sake, and in fact, their moral views consider art to be worthwhile even if no one experiences it. Their utility functions are linear in the amount of art that exists, and so they wish to maximize the expected amount of art in the galaxy -- converting planets and asteroids into van Gogh, Shakespeare, and Chopin.

However, they don't quite agree on which art is best. One couple wants to maximize paintings, feeling that a galaxy filled with paintings would be worth +3. A galaxy filled with sculptures would be +2. And a galaxy filled with poetry or music would be worthless: 0. The second couple values poetry at +3, sculptures at +2, and the other art at 0. The third values music at +3, sculptures at +2, and everything else at 0. Despite their divergent views, they manage to get along in the joint Martian voyage.

However, a few weeks into the trip, a terrestrial accident vaporizes Earth, leaving no one behind. The only humans are now the artists heading for Mars, where they land several months later.

The original plan had been for Earth to send more supplies following this crew, but now that Earth is gone, the colonists have only the minimal resources that the Martian base currently has in stock. They plan to grow more food [in their greenhouse](http://science1.nasa.gov/science-news/science-at-nasa/2004/25feb_greenhouses/), but this will take many months, and the artists will all starve in the meanwhile if they each stick around. They realize that it would be best if two of the couples sacrificed themselves so that the third would have enough supplies to continue to grow crops and eventually repopulate the planet.

Rather than fighting for control of the Martian base, which could be costly and kill everyone, the three couples realize that everyone would be better off in expectation if they selected a winner by lottery. In particular, they use a quantum random number generator to apportion 1/3 probabilities for each couple to survive. The lottery takes place, and the winner is the first couple, which values paintings most highly. The other two couples wish the winning couple the best of luck and then head to the euthanasia pods.

The pro-paintings couple makes it through the period of low food and manages to establish a successful farming operation. They then begin having children to populate the planet. After many generations, Mars is home to a thriving miniature city. All the inhabitants value paintings at +3, sculptures at +2, and everything else at 0, due to the influence of the civilization's founders.

By the year 2700, the city's technology is sufficient to deploy von Neumann probes throughout the galaxy, converting planets into works of art. The city council convenes a meeting to decide exactly what kind of art should be deployed. Because everyone in the city prefers paintings, the council assumes the case will be open and shut. But as a formality, they invite their local philosopher, Dr. Muchos Mundos, to testify.

> Council president: Dr. Mundos, the council has proposed to deploy von Neumann probes that will fill the galaxy with paintings. Do you agree with this decision?
> 
> Dr. Mundos: As I understand it, the council wishes to act in the optimal preference-utilitarian fashion on this question, right?
> 
> Council president: Yes, of course. The greatest good for the greatest number. Given that everyone who has any preferences about art most prefers a galaxy of paintings, we feel it's clear that paintings are what we should deploy. It's true that when this colony was founded, there were two other couples who would have wanted poetry and music, but their former preferences are far outweighed by our vast population that now wants paintings.
> 
> Dr. Mundos: I see. Are you familiar with the many-worlds interpretation (MWI) of quantum mechanics?
> 
> Council president: I'm a politician and not a physicist, but maybe you can give me the run-down?
> 
> Dr. Mundos: According to MWI, when quantum randomness occurs, it's not the case that just a single outcome is selected. Rather, all outcomes happen, and our experiences of the world split into different branches.
> 
> Council president: Okay. What's the relevance to art policy?
> 
> Dr. Mundos: Well, a quantum lottery was used to decide which colonizing couple would populate Mars. The painting lovers won in this branch of the multiverse, but the poetry lovers won in another branch with equal measure, and the music lovers won in a third branch, also with equal measure. Presumably the couples in those branches also populated Mars with a city about as populous as our own. And if they care about art for art's sake, regardless of whether they know about it or where it exists, then the populations of those cities in other Everett branches also care about what art _we_ deploy.
> 
> Council president: Oh dear, you're right. Our city contains M people, and suppose their cities have about the same populations. If we deploy paintings, our M citizens each get +3 of utility, and those in the other worlds get nothing. The aggregate is 3M. But if we deploy sculptures, which everyone values at +2, the total utility is 3 * 2M = 6M. This is much better than 3M for paintings.
> 
> Dr. Mundos: Yes, exactly. Of course, we might have some uncertainty over whether the populations in the other branches survived. But even if the probability they survived was only, say, 1/3, then the expected utility of sculptures would still be 2M for us plus (1/3)(2M + 2M) = 4M/3 for them. The sum is more than 3M, so it would still be better to do sculptures.

After further deliberation, the council agreed with this argument and deployed sculptures. The preference satisfaction of the poetry-loving and music-loving cities was improved.

Multiversal distribution of preferences
---------------------------------------

According to Max Tegmark's "[Parallel Universes](http://space.mit.edu/home/tegmark/PDF/multiverse_sciam.pdf)," there's probably an exact copy of you reading this article within 10^10^28^^ meters away and in practice, probably much closer. As Tegmark explains, this claim assumes only basic physics that most cosmologists take for granted. Even nearer than this distance are many people very similar to you but with minor variations -- e.g., with brown eyes instead of blue, or who prefer virtue ethics over deontology.

In fact, all possible people exist somewhere in the multiverse, if only due to random fluctuations of the type that produce [Boltzmann brains](https://en.wikipedia.org/wiki/Boltzmann_brain). Nick Bostrom calls these "[freak observers](http://www.anthropic-principle.com/?q=book/chapter_3#3c)." Just as there are art maximizers, there are also art minimizers who find art disgusting and want to eliminate as much of it as possible. For them, the thought of art triggers their brains' disgust centers instead of beauty centers.

However, the _distribution_ of organisms across the multiverse is not uniform. For instance, we should expect suffering reducers to be [much more common](http://rationalaltruist.com/2013/06/13/against-moral-advocacy/comment-page-1/#comment-481) than suffering increasers because organisms evolve to dislike suffering by themselves, their kin, and their reciprocal trading partners. Societies -- whether human [or alien](http://www.scifiideas.com/related/writing-advice/aliens-and-morality/) \-\- should often develop norms against cruelty for collective benefit.

Human values give us some hints about what values across the multiverse look like, because human values are a kind of [maximum likelihood estimator](https://en.wikipedia.org/wiki/Maximum_likelihood) for the mode of the multiversal distribution. Of course, we should expect some variation about the mode. Even among humans, some cultural norms are distinct and others [are universal](https://en.wikipedia.org/wiki/Human_universal). Probably values like not murdering, not causing unnecessary suffering, not stealing, etc. are more common among aliens than, say, the value of music or dance, which might be human-specific spandrels. Still, aliens may have their own spandrels that they call "art," and they might value those things.

Like human values, alien values might be mostly self-directed toward their own wellbeing, especially in their earlier Darwinian phases. Unless we meet the aliens face-to-face, we can't improve their welfare directly. However, the aliens may also have some outward-directed aesthetic and moral values that apply across space and time, like the value of art as seen by the art-maximizing cities on Mars in the previous section. If so, we can affect the satisfaction of these preferences by our actions, and presumably they should be included in preference-utilitarian calculations.

As an example, suppose there were 10 civilizations. All 10 valued reducing suffering and social equality. 5 of the 10 also valued generating knowledge. Only 1 of the 10 valued creating paintings and poetry. Suppose our civilization values all of those things. Perhaps previously we were going to spend money on creating more poetry, because our citizens value that highly. However, upon considering that poetry would not satisfy the preferences of the other civilizations, we might switch more toward knowledge and especially toward suffering reduction and equality promotion.

In general, considering the distribution of outward-directed preferences across the multiverse should lead us to favor more those preferences of ours that are more evolutionarily robust, i.e., that we predict more civilizations to have settled upon. One corollary is that we should care less about values that we have due to particular, idiosyncratic historical contingencies, such as who happened to win some very closely contested war, or what species were killed by a random asteroid strike. Values based on more inevitable historical trends should matter relatively more strongly.

Tyranny of the aliens?
----------------------

Suppose, conservatively, that for every one human civilization, there are 1000 alien civilizations that have some outward-directed preferences (e.g., for more suffering reduction, justice, knowledge, etc.). Even if each alien civilization cares only a little bit about what we do, collectively do their preferences outweigh our preferences about our own destiny? Would we find ourselves beholden to the tyranny of the alien majority about our behavior?

This question runs exactly parallel to the standard concern about tyranny of the majority for individuals within a society, so the same sorts of arguments will apply on each side. Just as in that case, it's possible aliens would place value on the ability of individual civilizations to make their own choices about how they're constituted without too much outside interference. Of course, this is just speculation.

Even if tyranny of the alien majority was the result, we might choose to accept that conclusion. After all, it seems to yield more total preference satisfaction, which is what the preference utilitarians were aiming for.

Direct welfare may often dominate
---------------------------------

In the preceding examples, I often focused on aesthetic values like art and knowledge for a specific reason: These are cases of preferences for something to exist or not where that thing does not itself have preferences. Art does not prefer for itself to keep existing or stop existing.

However, many human preferences have implications for the preferences of others. For instance, a preference by humans for more wilderness may mean vast numbers of additional wild animals, many of whom strongly (implicitly) prefer not to have endured the [short lives and painful deaths](http://www.utilitarian-essays.com/suffering-nature.html) inherent to the bodies in which they found themselves born. A relatively weak aesthetic preference for nature by a relatively small number of people is compared against strong hedonic preferences by large numbers of animals not to have existed. In this case, the preferences of the animals clearly dominate. The same is true for preferences about creating space colonies and the like: The preferences of the people, animals, and other agents in those colonies will tend to far outweigh the preferences of their creators.

Considering multiverse-wide aesthetic and moral preferences is thus cleanest in the case of preferences about inanimate things. Aliens' preferences about actions that affect the welfare of organisms in our civilization still matter, but relatively less than the contribution of their preferences about inanimate things.

Acknowledgments
---------------

This piece was inspired by Carl Shulman's "[Rawls' original position, potential people, and Pascal's Mugging](http://reflectivedisequilibrium.blogspot.com/2012/07/rawls-original-position-potential.html)," as well as a conversation with Paul Christiano.