I have a new essay in draft, "The Washout Argument Against Longtermism". As always, thoughts, comments, and objections welcome, either as comments on this post or by email to my academic address.
Abstract:
We cannot be justified in believing that any actions currently available to us will have a non-negligible positive influence on the billion-plus-year future. I offer three arguments for this thesis.
According to the Infinite Washout Argument, standard decision-theoretic calculation schemes fail if there is no temporal discounting of the consequences we are willing to consider. Given the non-zero chance that the effects of your actions will produce infinitely many unpredictable bad and good effects, any finite effects will be washed out in expectation by those infinitudes.
According to the Cluelessness Argument, we cannot justifiably guess what actions, among those currently available to us, are relatively more or less likely to have positive effects after a billion years. We cannot be justified, for example, in thinking that nuclear war or human extinction would be more likely to have bad than good consequences in a billion years.
According to the Negligibility Argument, even if we could justifiably guess that some particular action is likelier to have good than bad consequences in a billion years, the odds of good consequences would be negligibly tiny due to the compounding of probabilities over time.
For more details see the full-length draft.
A brief, non-technical version of these arguments is also now available at the longtermist online magazine The Latecomer.
[Midjourney rending of several happy dolphins playing]
Excerpt from full-length essay
If MacAskill’s and most other longtermists’ reasoning is correct, the world is likely to be better off in a billion years if human beings don’t go extinct now than if human beings do go extinct now, and decisions we make now can have a non-negligible influence on whether that is the case. In the words of Toby Ord, humanity stands at a precipice. If we reduce existential risk now, we set the stage for possibly billions of years of thriving civilization; if we don’t, we risk the extinction of intelligent life on Earth. It’s a tempting, almost romantic vision of our importance. I also feel drawn to it. But the argument is a card-tower of hand-waving plausibilities. Equally breezy towers can be constructed in favor of human self-extermination or near-self-extermination. Let me offer....
The Dolphin Argument. The most obvious solution to the Fermi Paradox is also the most depressing. The reason we see no signs of intelligent life elsewhere in the universe is that technological civilizations tend to self-destruct in short order. If technological civilizations tend to gain increasing destructive power over time, and if their habitable environments can be rendered uninhabitable by a single catastrophic miscalculation or a single suicidal impulse by someone with their finger on the button, then the odds of self-destruction will be non-trivial, might continue to escalate over time, and might cumulatively approach nearly 100% over millennia. I don’t want to commit to the truth of such a pessimistic view, but in comparison, other solutions seem like wishful thinking – for example, that the evolution of intelligence requires stupendously special circumstances (the Rare Earth Hypothesis) or that technological civilizations are out there but sheltering us from knowledge of them until we’re sufficiently mature (the Zoo Hypothesis).
Anyone who has had the good fortune to see dolphins at play will probably agree with me that dolphins are capable of experiencing substantial pleasure. They have lives worth living, and their death is a loss. It would be a shame if we drove them to extinction. Suppose it’s almost inevitable that we wipe ourselves out in the next 10,000 years. If we extinguish ourselves peacefully now – for example, by ceasing reproduction as recommended by antinatalists – then we leave the planet in decent shape for other species, including dolphins, which might continue to thrive. If we extinguish ourselves through some self-destructive catastrophe – for example, by blanketing the world in nuclear radiation or creating destructive nanotech that converts carbon life into gray goo – then we probably destroy many other species too and maybe render the planet less fit for other complex life.
To put some toy numbers on it, in the spirit of longtermist calculation, suppose that a planet with humans and other thriving species is worth X utility per year, a planet with other thriving species with no humans is worth X/100 utility (generously assuming that humans contribute 99% of the value to the planet!), and a planet damaged by a catastrophic human self-destructive event is worth an expected X/200 utility. If we destroy ourselves in 10,000 years, the billion year sum of utility is 10^4 * X + (approx.) 10^9 * X/200 = (approx.) 5 * 10^6 * X. If we peacefully bow out now, the sum is 10^9 * X/100 = 10^7 * X. Given these toy numbers and a billion-year, non-human-centric perspective, the best thing would be humanity’s peaceful exit.
Now the longtermists will emphasize that there’s a chance we won’t wipe ourselves out in a terribly destructive catastrophe in the next 10,000 years; and even if it’s only a small chance, the benefits could be so huge that it’s worth risking the dolphins. But this reasoning ignores a counterbalancing chance: That if human beings stepped out of the way a better species might evolve on Earth. Cosmological evidence suggests that technological civilizations are rare; but it doesn’t follow that civilizations are rare. There has been a general tendency on Earth, over long, evolutionary time scales, for the emergence of species with moderately high intelligence. This tendency toward increasing intelligence might continue. We might imagine the emergence of a highly intelligent, creative species that is less destructively Promethean than we are – one that values play, art, games, and love rather more than we do, and technology, conquering, and destruction rather less – descendants of dolphins or bonobos, perhaps. Such a species might have lives every bit as good as ours (less visible to any ephemeral high-tech civilizations that might be watching from distant stars), and they and any like-minded descendants might have a better chance of surviving for a billion years than species like ours who toy with self-destructive power. The best chance for Earth to host such a species might, then, be for us humans to step out of the way as expeditiously as possible, before we do too much harm to complex species that are already partway down this path.
Think of it this way: Which is the likelier path to a billion-year happy, intelligent species: that we self-destructive humans manage to keep our fingers off the button century after century after century somehow for ten million centuries, or that some other more peaceable, less technological clade finds a non-destructive stable equilibrium? I suspect we flatter ourselves if we think it’s the former.
This argument generalizes to other planets that our descendants might colonize in other star systems. If there’s even a 0.01% chance per century that our descendants in Star System X happen to destroy themselves in a way that ruins valuable and much more durable forms of life already growing in Star System X, then it would be best overall for them never to have meddled, and best for us now to peacefully exit into extinction rather than risk producing descendants who will expose other star systems to their destructive touch.
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My aim with the Dolphin Argument... is not to convince readers that humanity should bow out for the sake of other species.... Rather, my thought is this: It’s easy to concoct stories about how what we do now might affect the billion-year future, and then to attach decision-theoretic numbers to those stories. We lack good means for evaluating these stories. We are likely just drawn to one story or another based on what it pleases us to think and what ignites our imagination.
Ha, I was just going to write that there's an interesting medium term, and then found that that's the entire last section of your essay! So yes, I'm very much in agreement on that.
I think that MacAskill long term and your medium term are both just attempts to factor in *all the consequences we know* for consequentialist arguments. MacAskill and you (and I) may disagree on what we can know and what we can't, but they all seem to be efforts to extend the scope of consequences to longer terms, where the resolution may be lower, but we can nonetheless see enough features of the picture clearly to make some important judgments.
Both of these approaches remain susceptible to "old man lost his horse" style arguments. If there is a realm of consequences completely outside what is knowable, then it doesn't matter how accurately we've calibrated our understanding of known consequences over the short, medium, or long term.
I feel like the question is answered over the scale of decades: experience suggests that we do in fact know what the likely consequences of most kinds of action for a person, community, and state over the span of a human lifetime. Beyond that, things get less certain. I'd be worried trying to push things beyond about 200 years: past that timeframe, I think the unknown consequences start to overwhelm the known consequences for pretty much all human actions, with the exception of human extinction.
(I'm chinaphil from your blogger blog.)