This post is also available on the EA Forum.

Summary: Having thought a bunch about acausal trade — and proven some theorems relevant to its feasibility — I believe there do not exist powerful information hazards about it that stand up to clear and circumspect reasoning about the topic.  I say this to be comforting rather than dismissive; if it sounds dismissive, I apologize.  

With that said, I have four aims in writing this post:

1. Dispelling myths.  There are some ill-conceived myths about acausal trade that I aim to dispel with this post.  Alternatively, I will argue for something I'll call acausal normalcy as a more dominant decision-relevant consideration than one-on-one acausal trades.  
2. Highlighting normalcy.  I'll provide some arguments that acausal normalcy is more similar to human normalcy than any particular acausal trade is to human trade, such that the topic of acausal normalcy is — conveniently — also less culturally destabilizing than (erroneous) preoccupations with 1:1 acausal trades. 
3. Affirming AI safety as a straightforward priority.  I'll argue that for most real-world-prevalent perspectives on AI alignment, safety, and existential safety, acausal considerations are not particularly dominant, except insofar as they push a bit further towards certain broadly agreeable human values applicable in the normal-everyday-human-world, such as nonviolence, cooperation, diversity, honesty, integrity, charity, and mercy.  In particular, I do not think acausal normalcy provides a solution to existential safety, nor does it undermine the importance of existential safety in some surprising way. 
4. Affirming normal human kindness.  I also think reflecting on acausal normalcy can lead to increased appreciation for normal notions of human kindness, which could lead us all to treat each other a bit better.  This is something I wholeheartedly endorse.

Caveat 1: I don't consider myself an expert on moral philosophy, and have not read many of the vast tomes of reflection upon it.  Despite this, I think this post has something to contribute to moral philosophy, deriving from some math-facts that I've learned and thought about over the years, which are fairly unique to the 21st century.

Caveat 2: I’ve been told by a few people that thinking about acausal trade has been a mental health hazard for people they know.  I now believe that effect has stemmed more from how the topic has been framed (poorly) than from ground-truth facts about how circumspect acausal considerations actually play out.  In particular over-focussing on worst-case trades, rather than on what trades are healthy or normal to make, is not a good way to make good trades.

Introduction

Many sci-fi-like stories about acausal trade invoke simulation as a key mechanism.  

The usual set-up — which I will refute — goes like this.  Imagine that a sufficiently advanced human civilization (A) could simulate a hypothetical civilization of other beings (B), who might in turn be simulating humanity (B(A)) simulating them (A(B(A)) simulating humanity (B(A(B(A)))), and so on.  Through these nested simulations, A and B can engage in discourse and reach some kind of agreement about what to do with their local causal environments.  For instance, if A values what it considers “animal welfare” and B values what it considers “beautiful paperclips”, then A can make some beautiful paperclips in exchange for B making some animals living happy lives.

An important idea here is that A and B might have something of value to offer each other, despite the absence of a (physically) causal communication channel.  While agreeing with that idea, there are three key points I want to make that this standard story is missing:

1. Simulations are not the most efficient way for A and B to reach their agreement. Rather, writing out arguments or formal proofs about each other is much more computationally efficient, because nested arguments naturally avoid stack overflows in a way that nested simulations do not.  In short, each of A and B can write out an argument about each other that self-validates without an infinite recursion.  There are several ways to do this, such as using Löb's Theorem-like constructions (as in this 2019 JSL paper), or even more simply and efficiently using Payor's Lemma (as in this 2023 LessWrong post).

2. One-on-one trades are not the most efficient way to engage with the acausal economy.  Instead, it's better to assess what the “acausal economy” overall would value, and produce that, so that many other counterparty civilizations will reward us simultaneously.  Paperclips are intuitively a silly thing to value, and I will argue below that there are concepts about as simple as paperclips that are much more universally attended to as values.  

3. Acausal society is more than the acausal economy.  Even point (2) isn't quite optimal, because we as a civilization get to take part in the decision of what the acausal economy as a whole values or tolerates.  This can include agreements on norms to avoid externalities — which are just as simple to write down as trades — and there are some norms we might want to advocate for by refusing to engage in certain kinds of trade (embargoes).  In other words, there is an acausal society of civilizations, each of which gets to cast some kind of vote or influence over what the whole acausal society chooses to value.

This brings us to the topic of the present post: acausal normalcy, or perhaps, acausal normativity.  The two are cyclically related: what's normal (common) creates a Schelling point for what's normative (agreed upon as desirable), and conversely.  Later, I'll argue that acausal normativity yields a lot of norms that are fairly normal for humans in the sense of being commonly endorsed, which is why I titled this post "acausal normalcy".

A new story to think about: moral philosophy

Instead of fixating on trade with a particular counterparty B — who might end up treating us quite badly like in stories of the so-called "basilisk" — we should begin the process of trying to write down an argument about what is broadly agreeably desirable in acausal society.

As far as I can tell, humanity has been very-approximately doing this for a long time already, and calling it moral philosophy.  This isn't to say that all moral philosophy is a good approach to acausal normativity, nor that many moral philosophers would accept acausal normativity as a framing on the questions they are trying to answer (although some might).  I'm merely saying that among humanity's collective endeavors thus far, moral philosophy — and to some extent, theology — is what most closely resembles the process of writing down an argument that self-validates on the topic of what {{beings reflecting on what beings are supposed to do}} are supposed to do.

This may sound a bit recursive and thereby circular or at the very least convoluted, but it needn't be.  In Payor's Lemma — which I would encourage everyone to try to understand at some point — the condition ☐(☐x → x) → x unrolls in only 6 lines of logic to yield x. In exactly the same way, the following types of reasoning can all ground out without an infinite regress:

1. reflecting on {reflecting on whether x should be a norm, and if it checks out, supporting x} and if that checks out, supporting x as a norm
2. reflecting on {reflecting on whether to obey norm x, and if that checks out, obeying norm x} and if that checks out, obeying norm x

I claim the above two points are (again, very-approximately) what moral philosophers and applied ethicists are doing most of the time.  Moreover, to the extent that these reflections have made their way into existing patterns of human behavior, many normal human values are probably instances of the above.  

(There's a question of whether acausal norms should be treated as "terminal" values or "instrumental" values, but I'd like to side-step that here.  Evolution and discourse can both turn instrumental values into terminal values over time, and conversely.  So for any particularly popular acausal norm, probably some beings uphold it for instrumental reasons while others uphold it has a terminal value.)

Which human values are most likely to be acausally normal?

A complete answer is beyond this post, and frankly beyond me.  However, as a start I will say that values to do with respecting boundaries are probably pretty normal from the perspective of acausal society.  By boundaries, I just mean the approximate causal separation of regions in some kind of physical space (e.g., spacetime) or abstract space (e.g., cyberspace).  Here are some examples from my «Boundaries» Sequence:

• a cell membrane (separates the inside of a cell from the outside);
• a person's skin (separates the inside of their body from the outside);
• a fence around a family's yard (separates the family's place of living-together from neighbors and others);
• a digital firewall around a local area network (separates the LAN and its users from the rest of the internet);
• a sustained disassociation of social groups (separates the two groups from each other)
• a national border (separates a state from neighboring states or international waters).

Figure 1: Cell membranes, skin, fences, firewalls, group divisions, and state borders as living system boundaries.

By respecting a boundary I mean approaching boundaries in ways that are gated on the consent of the person or entity on the other side of the boundary.  For instance, the norm 

• "You should get my consent before entering my home" 

has more to do with respecting a boundary than the norm

• "You should look up which fashion trends are in vogue each season and try to copy them."

Many people have the sense that the second norm above is more shallow or less important than the first, and I claim this is because the first norm has to do with respecting a boundary.  Arguing hard for that particular conclusion is something I want to skip for now, or perhaps cover in a later post.  For now, I just want to highlight some more boundary-related norms that I think may be acausally normal:

• "If I open up my mental boundaries to you in a way that lets you affect my beliefs, then you should put beliefs into my mind that that are true and helpful rather than false or harmful."
• "If Company A and Company B are separate entities, Company A shouldn't have unfettered access to Company B's bank accounts."

Here are some cosmic-scale versions of the same ideas:

• Alien civilizations should obtain our consent in some fashion before visiting Earth.
• Acausally separate civilizations should obtain our consent in some fashion before invading our local causal environment with copies of themselves or other memes or artifacts.

In that spirit, please give yourself time and space to reflect on whether you like the idea of acausally-broadly-agreeable norms affecting your judgment, so you might have a chance to reject those norms rather than being automatically compelled by them.  I think it's probably pretty normal for civilizations to have internal disagreements about what the acausal norms are.  Moreover, the norms are probably pretty tolerant of civilizations taking their time to figure out what to endorse, because probably everyone prefers a meta-norm of not making the norms impossibly difficult to discover in the time we're expected to discover them in.

Sound recursive or circular?  Yes, but only in the way that we should expect circularity in the fixed-point-finding process that is the discovery and invention of norms.

How compelling are the acausal norms, and what do they imply for AI safety?

Well, acausal norms are not so compelling that all humans are already automatically following them.  Humans treat each other badly in a lot of ways (which are beyond the scope of this post), so we need to keep in mind that norms — even norms that may be in some way fundamental or invariant throughout the cosmos — are not laws of physics that automatically control how everything is.

In particular, I strongly suspect that acausal norms are not so compelling that AI technologies would automatically discover and obey them.  So, if your aim in reading this post was to find a comprehensive solution to AI safety, I'm sorry to say I don't think you will find it here.  

On the other hand, if you were worried that somehow acausal considerations would preclude species trying to continue their own survival, I think the answer is "No, most species who exist are species that exist because they want to exist, because that's a stable fixed-point.  As a result, most species that exist don't want the rules to say that they shouldn't exist, so we've agreed not to have the rules say that."

Conclusion

Acausal trade is less important than acausal agreement-about-norms, and acausal norms are a lot less weird and more "normal" than acausal trades.  The reason is that acausal norms are created through reasoning rather than computationally expensive simulations, and reasoning is something moral philosophy and common sense moral reflection has been doing a lot of already.  

Unfortunately, the existence of acausal normativity is not enough to automatically save us from moral atrocities, not even existential risk.  

However, a bunch of basic human norms to do with respecting boundaries might be acausally normal because of 

• how fundamental boundaries are for the existence and functioning of moral beings, and hence
• how agreeable the idea of respecting boundaries is likely to be, from the perspective of acausal normative reflection.

So, while acausal normalcy might not save us from a catastrophe, it might help us humans to be somewhat kinder and more respectful toward each other, which itself is something to be valued.