OK, so, the most important thing to understand about the Dark Forest hypothesis is that Cixin Liu is not necessarily making a serious argument for it as a realistic model of how the universe works. The novels are works of fiction, and while I will trash Cixin's prose to the ends of the Earth (it is dire, and absolutely none of my complaints have anything to do with translation; the shift from Chinese to English didn't magically replace dialogue and character action with endless tracts of dry narration, that's just how he writes, and it's bad), I think his grasp of themes is actually really, really good. I've often commented that I would love to see Liu take all of his ideas and collaborate with a better writer on putting them into text.

In the case of Remembrance of Earth's Past, the core themes of the series as a whole are all about altruism and cooperation, and the Dark Forest Hypothesis exists as a juxtaposition and foil to those ideas. He's not necessarily advocating for it, it just works for what his story is trying to say about the human condition. The Dark Forest is, in a sense, the ultimate villain of the series.

I also want to note that while earlier versions of the theory existed, there are subtle but important differences in how they're expressed. Hawking et al are/were proponents of the idea that aliens may be hiding, but The Dark Forest specifically presents the argument that no only is everyone hiding from Space Hitler, but that everyone is Space Hitler, as non-genocidal civilizations are inevitably wiped out. That's what I take issue with.

As for why I think the theory is - removed from it's context as a dark backdrop against which to write a story of hope - a crock of shit...

Well, OK, I don't think it's a crock of shit in the sense that it's utterly impossible. But it's presented, especially by fans, as a kind of inevitable logical assertion, a fait-a-complit that cannot be challenged because it's so utterly self-evident. This is nonsense. While the theory is technically possible, all of our available evidence suggests that it's extremely unlikely.

First, at a really basic level, 100% of our observations of intelligent species refute it. Humans constantly and enthusiastically blast our position into space, and the apparently irrefutable logic of the Dark Forest hypothesis hasn't slowed our enthusiasm for doing so by one iota.

"But humans are an outlier!"

Based on what evidence? We have zero empirical observations to base that claim on. And no, I'm not claiming that one (1) species constitutes a statistically significant observation for my argument; rather I'm pointing to the fact that our empirical observations arguing for dark forest are zero (0), and our empirical observations against are > 0, and at some point proponents of the theory kind of have to deal with that fact. It's just as absurd to claim that humans are an outlier as it is to claim that every species in the universe must inherently be like us.

What we do know that is all life on Earth with any degree of intelligence demonstrates curiosity. Curiosity is, as best we can tell, an essential component of applied intelligence. An incurious species will never smash a stick with a rock and learn the concept of a hammer. Curiosity compels us to want to learn about the unknown. Liu presents this idea that inter-species cooperation will always be an unbridgeable gap because truly alien creatures from truly alien environments will never be able to comprehend each other's goals and motivations, and that's frankly ludicrous. The drive to understand the unknown is what made the first ape pick up a burning stick and realise it could keep their tribe warm.

(Am I arguing that Project Hail Mary is basically a sufficient revocation of the Dark Forest Hypothesis entirely on its own? Broadly, yes.)

Further to the lack of evidence is the lack of any observable evidence of the ongoing galactic genocide that we are apparently endlessly surrounded by. We know when stars should die - we're actually pretty good at it - so spotting when stars are being blown up by civilisation destroying weaponry wouldn't be that hard.

Then we get to the fundamental flaws in the game theory. Liu proposes a forest full of hunters with rifles shooting each other from the darkness, but never once contemplates what happens if the hunter you fire at has a friend. Given the nature of the weaponry employed in the story, which is never shown to be capable of destroying more than one star system at a time, that friend doesn't even have to be an allied civilisation, it can just be an extra-solar colony. The entire logic of the "Always strike first" conclusion falls apart at this point. You detect a star system that contains a nascent alien civilisation, you blow it up with a photoid. Turns out you detected one of that species first extra-solar colonies, and their homeworld immediately conceals itself, builds photoids, finds you and kills you. Hard to do, but entirely worth the effort now that you've made it essential to their survival.

The hunters gun reveals him when he fires, and why shouldn't it? There's no reason to believe that methods of interstellar destruction are entirely undetectable to observers. Logically, opening fire is a terrible decision; you have declared to everyone around you that you operate on a first strike principle, making yourself an immediate target for destruction, potentially by a group of altruistic civilisations who will immediately choose to cooperate against you. It's really not hard to formulate the logic of the dark forest in such a way that, rather than only paranoid, genocidal civilisations surviving, it is the exact opposite; that cooperators have an inherent advantage that would lead to only cooperators surviving. The theory as presented just relies on assuming that all of its suppositions are correct while ignoring alternative possibilities.

The argument the theory presents against the likelihood of cooperation is the notion that we exist in a universe of finite resources, but increasingly our observations of the universe show that there is a LOT more matter than there is life, and at a certain level of technology all matter is usable resources. Basically once we can start printing carbon atoms we're close enough to Star Trek replicators as makes no odds. Carbon is literally the fourth most abundant element in the universe. The Trisolarans can turn protons into multidimensional computers but they can't fabricate food from the carbon in asteroids? That is an absolutely demented proposal. In the first Culture novel Ian Banks lays out how the Culture is basically undefeatable in conventional warfare because they've completely transcended the need for territory. Planets don't matter when you can build spaceships the size of continents. The idea that advanced space-faring civilisations would be coming to blows over resources beggars belief. The Trisolarans have already demonstrated the technology required to just become a completely space-faring civilization.

Hell, if the entire driver of a lack of cooperation is scarcity of resources, why the fuck would we be blowing up each other's star systems with all those valuable life-supporting planets? If the existence of advanced life is somehow utterly dependent on life-supporting planets in a way that is fundamentally unsolvable, you'd be insane to go around destroying them.

None of this is fundamentally dispositive to the theory. That's not what I'm trying to claim. If it has a 0.0001% chance of being true then it's still plausible. My point is simply that in order for it to be meaningful there are so many specific assumptions that would first have to be proven, and which, frankly, fly in the face of what available evidence we have. Essentially, we would have to be entirely wrong in many of our current observations of the state of the universe. You might as well assert that the moon is actually made of cheese, it's just buried deep beneath all the bits we've studied. It's a theory that seems entirely logical, as long as you ignore the vast majority of what we know about the universe.

And I do want to reiterate what I said at the top; the Dark Forest Hypothesis is almost certainly a bad theory because it's not meant to stand up as a theory. It's more than likely just meant to be a piece of sufficiently plausible sci-fi technobabble - just like warp drive - that it can support what the story is trying to say, not an actual theory that stands up to scrutiny. I just dislike that a) it really does rely on a LOT of bad assumptions, to the point where I was questioning it throughout the story, and b) people act like it is some kind of irrefutable masterstroke of game theory.

Stephen Hawking is a major proponent of this hypothesis.

was

As I explained - it feeled fresh. I can't explain why, but I can't put it down while reading.

I don't try to convince people, who read this book, that it's great. I address people who haven't - you should give it a chance.