Multiversal Morals
In 1844 Arthur Schopenhauer wrote:
“Now this world is so arranged as to be able to maintain itself with great difficulty; but if it were a little worse, it could no longer maintain itself. Consequently a worse world, since it could not continue to exist, is absolutely impossible: thus this world itself is the worst of all possible worlds.”
This is an early example of a kind of modal thinking that today is called ‘multiverse theory,’ the idea that our reality is only one of many. Schopenhauer only referred to other worlds in the hypothetical, but to modern theorists these alternate realities are entirely literal. Cosmologist Max Tegmark, one of the best sources for multiversal understanding, has argued that any universe that can be described by a mathematical system must be considered as real as our own. If you can imagine it, it exists. Multiverse theory often comes up in conjunction with discussions on quantum physics, or the origins of the universe. Neil DeGrasse Tyson and Stephen Hawking have both expressed belief in variations of the concept of multiverse, and as a result the theory has found prominence in the mainstream understanding of cutting edge scientific thought.
But the multiverse is not technically a scientific concept — at least, not in Tegmark’s formulation of the idea, which he calls “ultimate ensemble theory.” Because it describes other realities that never touch our own, this theory is unfalsifiable, and not a scientific claim. It is, however, a metaphysical claim, and can still be considered in terms of its impact on metaphysical questions. Tegmark isn’t much bothered by the moral implications of his idea, but I am. If every mathematically described universe exists, that means every possible sequence of events exists somewhere. Does choice matter if, somewhere, an alternate version of you makes the opposite decision?
The first thing to do is dispense with the notion of exceptionalism — our world is not inherently any more real, or important, or true, than any other in the multiverse. The sci-fi idea that the version of you reading this is the ‘original’ you has nothing to do with ultimate ensemble theory, and everything to do with convenient storytelling. Every version of you is equally valid and equally valuable. All of the yous are authentic. If one version of you chooses the red pill and another version chooses the blue pill, both choices have the same significance. This isn’t hard logic to follow, but maybe you can see the ethical roadblock ahead.
Let’s imagine two alternative versions of you (neither of which are you reading this now) which we’ll call you-1 and you-2. Both yous meet someone on the street. You-1 walks past him like a normal human being — maybe they wave hello at each other as they pass. You-2 pulls out a steak knife and murders the innocent pedestrian like a psychotic slasher villain. Preposterous? Remember, if it can exist, it does. The world with murderous you-2 in it (world-2) is out there somewhere, and that world is just as legitimate as world-1. Both versions of events have taken place.
Tomorrow you-reading-this will go outside and pass someone on the street, with a steak knife in your pocket, and you will suddenly have to choose between world-1 and world-2. Does it matter which one you choose? “Murder is wrong,” but if you don’t murder in this world you will in another, which is just as evil. “I don’t want to be punished,” but if you avoid punishment for murder in this world, you’ll be punished in another world, and the version of you that gets punished is just as legitimate as the version of you that escapes punishment. There’s no actual benefit to not doing wrong, or avoiding suffering, since the alternative outcome will always transpire somewhere else across the multiverse and it’s equally as significant as if it transpired here.
“As the version of me currently experiencing this world, I want to experience as little suffering as possible even if technically I do suffer somewhere else. Screw that other version of me, I’m getting mine.” This is a legitimate viewpoint, but still not enough to resolve our ethical concerns. Rational egoism is already a house built on shifting sand, but bring it into multiverse theory and it gets worse. Egoism at least attempts to point toward a moral goal, the good of all people together. You’ve just denied morality entirely. You’re not an egoist, you’re a hedonist, with full license to do whatever you want as long as you don’t get caught. Worse, you’ve given that same license to everyone else. How can you blame Minor Keith for wreaking havoc across Latin America in the name of profit? He never suffered for it, and if he didn’t do it in this world he would have in another.
To his credit, Tegmark has tried to resolve this issue in his responses to concerned readers on his personal page: in response to the question “how do I know I won’t rob a gas station in an alternate reality?” he says:
However, to cheer you up: even if some of your twins hold up gas stations, most of your twins certainly don’t, given what I already know about your personality; it’s important to keep track of the statistics, since even if everything conceivable happens somewhere, really freak events happen only exponentially rarely.
According to Tegmark, robbing a gas station (or killing someone on the street) is antithetical to your nature, and there aren’t just two worlds, but infinite. So perhaps you-2 and you-4155 commit murder, but yous-[3–4154] don’t. Unfortunately, that still doesn’t resolve the problem of non-exceptionalism: why shouldn’t world-2 be this world? And again, if you’re afraid of the police just return to Keith: maybe he acts more humanely in many timelines and only enacts United Fruit’s reign of terror in a few, but why shouldn’t this world be one of those few? The same number of people will suffer across the multiverse either way.
It gets worse: not only does UE theory excuse Keith’s actions by making the total amount of suffering in the multiverse the same no matter what he does, if he were to find out about UE the suffering in the multiverse might actually increase. Pretend for the sake of argument that most Keiths feel the prick of conscience and remain a relatively small-time fruit seller in New York. Keith-2 and Keith-4155 made decisions that led to the Banana Massacre of 1928, but Keiths-[3–4154] did not, due to feelings of humanity. But suppose that a cosmologist approached Keith in his early years in a majority of timelines (since it would be in accordance with his character to do so) and explained to him all the implications of ultimate ensemble theory. Also suppose that the cosmologist is very persuasive, and converts Keith entirely almost every time they meet. Now a majority of Keiths believe that it doesn’t matter whether they listen to that prick of conscience or not, since each one believes that other Keiths in other realities will do so either way. Keith-3 never meets the cosmologist, Keith-4 is unconvinced, but Keiths-[5–4154] suddenly feel a moral burden lifted from their shoulders.
With all these Keiths outsourcing their moral responsibilities to each other, none of them actually do the right thing. Each one pursues his own egoistic good, counting on alternate reality versions of himself to do the right thing in accordance with the conscience he would otherwise follow. Now instead of two bad Keiths, we only have two or three good ones. Understanding UE theory and its moral implications has given each Keith the freedom to do evil for his own benefit, and dramatically increased the amount of suffering across the multiverse due to United Fruit’s rise. If Tegmark’s ultimate ensemble theory is true, the only really morally reprehensible act possible is to tell people about it. If Tegmark is correct, I hope that it is not usually in his nature to publicize his theory, and we are unfortunate enough to exist in one of the few outlier realities where he does. Otherwise, the multiverse is about to get a whole lot nastier.
