Yeah, random quantum fluctuations that just happen to form a working brain out of unliving matter? What’s the difference between that and life evolving out of the primordial soup?
The other problem is that the argument presupposes that a real universe exists in which a brain could spring into being out of random virtual particles. How do we know how virtual particles work? Is it…by observing the universe and figuring it out? Except if we’re just a random brain thrown together by random quantum fluctuations, with fake memories and fake sense impressions formed by the same random quantum virtual particles, then such a brain’s ideas about how the universe actually works are sure to be false. Including that brain’s ideas about how brains could be randomly created by random quantum whatevers. That brain’s theories about how the universe works would have no relation to the actual working of the universe.
So, you are a brain sitting here, and this thought about how brains might randomly appear in the universe has somehow entered your brain. How did it do so? Did it do so because some other brain observed the universe and formulated this theory about how this is a possibility, and then communicated the idea to your brain? Or did your brain just appear in an empty universe by accident, with this thought randomly implanted in it about how brains might appear in an empty universe by accident? And your brain experiencing this momentary existence and thoughts is almost certainly going to go back into the quantum foam in the next nanosecond?
How exactly could your randomly assembled brain form this correct theory about how brains could arise randomly?
Here’s the thing. I agree that the brains and senses we have, which are the product of evolution, are fallible. They don’t impart absolute truth upon us, they’re just machines that give the meatbags they’re part of a slightly higher chance of replication before disintegration. But the simplest way to give your meatbag a better chance of replication is by some sort of correspondence between the actually existing universe and the internal model and instincts of the brain sensing the universe. If your brain can feel heat and avoid fire, feel hunger and eat, feel thirst and drink, and deposit gametes in an environment likely to lead to the development of those gametes, then there will be more of that sort of brain in future generations, and fewer brains that don’t.
And of course we have very good evidence that our brains are pretty good and understanding the environment we evolved to survive in, but pretty terrible and understanding parts of the universe that didn’t matter to our replication. So we don’t understand relativity, we can’t sense all sorts of electromagnetic radiation, we get confused about whether the Earth is flat or spherical, we can look at a picture of a human female and become sexually aroused even though there isn’t really a human female present, and on and on. This is why we need telescopes and Geiger counters and voltage meters and so on, that convert the phenomenon we can’t sense directly into ones we can sense directly.
Of course, it could be that this is all nonsense, and there really is absolutely no correspondence between our senses and thoughts and the actual universe. If somebody thought this was true, why would they bother talking about it on the internet? It’s just solipsism, which needs no refutation.