How does that cash out if not in terms of picking a random agent, or random circumstances in the universe? So, remember, the moral value of the universe according to my ethical system depends on P(I’ll be satisfied | I’m some creature in this universe).
There must be some reasonable way to calculate this. And one that doesn’t rely on impossibly taking a uniform sample from a set that has none. Now, we haven’t fully formalized reasoning and priors yet. But there is some reasonable prior probability distribution over situations you could end up in. And after that you can just do a Bayesian update on the evidence “I’m in universe x”.
I mean, imagine you had some superintelligent AI that takes evidence and outputs probability distributions. And you provide the AI with evidence about what the universe it’s in is like, without letting it know anything about the specific circumstances it will end up in. There must be some reasonable probability for the AI to assign to outcomes. If there isn’t, then that means whatever probabilistic reasoning system the AI uses must be incomplete.
It really should seem unreasonable to suppose that in the 99.9% universe there’s a 99.9% chance that you’ll end up happy! Because the 99.9% universe is also the 0.1% universe, just looked at differently. If your intuition says we should prefer one to the other, your intuition hasn’t fully grasped the fact that you can’t sample uniformly at random from an infinite population.
I’m surprised you said this and interested in why. Could you explain what probability you would assign to being happy in that universe?
I mean, conditioning on being in that universe, I’m really not sure what else I would do. I know that I’ll end up with my happiness determined by some AI with a pseudorandom number generator. And I have no idea what the internal state of the random number generator will be. In Bayesian probability theory, the standard way to deal with this is to take a maximum entropy (i.e. uniform in this case) distribution over the possible states. And such a distribution would imply that I’d be happy with probability 99.9%. So that’s how I would reason about my probability of happiness using conventional probability theory.
Further further further, let me propose another hypothetical scenario in which an AI generates random people. This time, there’s no PRNG, it just has a counter, counting up from 1. And what it does is to make 1 happy person, then 1 unhappy person, then 2 happy people, then 6 unhappy people, then 24 happy people, then 120 unhappy people, …, then n! (un)happy people, then … . How do you propose to evaluate the typical happiness of a person in this universe? Your original proposal (it still seems to me) is to pick one of these people at random, which you can’t do. Picking a state at random seems like it means picking a random positive integer, which again you can’t do. If you suppose that the state is held in some infinitely-wide binary thing, you can choose all its bits at random, but then with probability 1 that doesn’t actually give you a finite integer value and there is no meaningful way to tell which is the first 0!+1!+...+n! value it’s less than. How does your system evaluate this universe?
I’m not entirely sure how my system would evaluate this universe, but that’s due to my own uncertainty about what specific prior to use and its implications.
But I’ll take a stab at it. I see the counter alternates through periods of making happy people and periods of making unhappy people. I have no idea which period I’d end up being in, so I think I’d use the principle of indifference to assign probability 0.5 to both. If I’m in the happy period, then I’d end up happy, and if I’m in the unhappy period, I’d end up unhappy. So I’d assign probability approximately 0.5 to ending up happy.
Further further, your prescription in this case is very much not the same as the general prescription you stated earlier. You said that we should consider the possible lives of agents in the universe. But (at least if our AI is producing a genuinely infinite amount of pseudorandomness) its state space is of infinite size, there are uncountably many states it can be in, but (ex hypothesi) it only ever actually generates countably many people. So with probability 1 the procedure you describe here doesn’t actually produce an inhabitant of the universe in question. You’re replacing a difficult (indeed impossible) question—“how do things go, on average, for a random person in this universe?”—with an easier but different question—“how do things go, on average, for a random person from this much larger uncountable population that I hope resembles the population of this universe?”. Maybe that’s a reasonable thing to do, but it is not what your theory as originally stated tells you to do and I don’t see any obvious reason why someone who accepted your theory as you originally stated it should behave as you’re now telling them they should.
Oh, I had in mind that the internal state of the pseudorandom number generator was finite, and that each pseudorandom number generator was only used finitely-many times. For example, maybe each AI on its world had its own pseudorandom number generator.
And I don’t see how else I could interpret this. I mean, if the pseudorandom number generator is used infinitely-many times, then it couldn’t have outputted “happy” 99.9% of the time and “unhappy” 0.1% of the time. With infinitely-many outputs, it would output “happy” infinitely-many times and output “unhappy” infinitely-many times, and thus the proportion it outputs “happy” or “unhappy” would be undefined.
Returning to my original example, let me repeat a key point: Those two universes, generated by biased coin-flips, are with probability 1 the same universe up to a mere rearrangement of the people in them. If your system tells us we should strongly prefer one to another, it is telling us that there can be two universes, each containing the same infinitely many people, just arranged differently, one of which is much better than the other. Really?
Yep. And I don’t think there’s any way around this. When talking about infinite ethics, we’ve had in mind a canonically infinite universe: one that, for every level of happiness, suffering, satisfaction, and dissatisfaction, there exists infinite many agents with that level. It looks like this is the sort of universe we’re stuck in.
So then there’s no difference in terms of moral value of two canonically-infinite universes except the patterning of value. So if you want to compare the moral value of two canonically-infinite universes, there’s just nothing you can do except to consider the patterning of values. That is, unless you want to consider any two canonically-infinite universes to be of equivalent moral value, which doesn’t seem like an intuitively desirable idea.
The problem with some of the other infinite ethical systems I’ve seen is that they would morally recommend redistributing unhappy agents extremely thinly in the universe, rather than actually try to make them happy, provided this was easier. As discussed in my article, my ethical system provides some degree of defense against this, which seems to me like a very important benefit.
I do think JBlack understands the idea of my ethical system and is using it appropriately.
my system provides a method of evaluating the moral value of a specific universe. The point of moral agents to to try to make the universe one that scores highlly on this moral valuation. But we don’t know exactly what universe we’re in, so to make decisions, we need to consider all universes we could be in, and then take the action that maximizes the expected moral value of the universe we’re actually in.
For example, suppose I’m considering pressing a button that will either make everyone very slightly happier, or make everyone extremely unhappy. I don’t actually know which universe I’m in, but I’m 60% sure I’m in the one that would make everyone happy. Then if I press the button, there’s a 40% chance that the universe would end up with very low moral value. That means pressing the button would not in expectation decrease the moral value of the universe, so my morally system would recommend not pressing it.
I think to some extent you may be over-thinking things. I agree that it’s not completely clear how to compute P(“I’m satisfied” | “I’m in this universe”). But to use my moral system, I don’t need a perfect, rigorous solution to this, nor am I trying to propose one.
I think the ethical system provides reasonably straightforward moral recommendations in the situations we could actually be in. I’ll give an example of such a situation that I hope is illuminating. It’s paraphrased from the article.
Suppose you can have the ability to create safe AI and are considering whether my moral system recommends doing so. And suppose if you create safe AI everyone in your world will be happy, and if you don’t then the world will be destroyed by evil rogue AI.
Consider an agent that knows it will be in this universe, but nothing else. Well, consider the circumstances, “I’m an agent in an Earth-like world that contains someone who is just like gjm and in a very similar situation who has the ability to create safe AI”. That above description has finite description length, and the AI has no evidence ruling it out. So it must have some non-zero probability of ending up in such a situation, conditioning on being somewhere in this universe.
All the gjms have the same knowledge and value and are in pretty much the same circumstances. So their actions are logically constrained to be the same as yours. Thus, if you decide to create the AI, you are acausally determining the outcome of arbitrary agents in the above circumstances, by making such an agent end up satisfied when they otherwise wouldn’t have been. Since an agent in this universe has non-zero probability of ending up in those circumstances, by choosing to make the safe AI you are increasing the moral value of the universe.