If the "boring view" of reality is correct, then you can never predict anything irreducible because you are reducible. You can never get Bayesian confirmation for a hypothesis of irreducibility, because any prediction you can make is, therefore, something that could also be predicted by a reducible thing, namely your brain.
Benja Fallenstein commented:
I think that while you can in this case never devise an empirical test whose outcome could logically prove irreducibility, there is no clear reason to believe that you cannot devise a test whose counterfactual outcome in an irreducible world would make irreducibility subjectively much more probable (given an Occamian prior).
Without getting into reducibility/irreducibility, consider the scenario that the physical universe makes it possible to build a hypercomputer —that performs operations on arbitrary real numbers, for example —but that our brains do not actually make use of this: they can be simulated perfectly well by an ordinary Turing machine, thank you very much...
Well, that's a very intelligent argument, Benja Fallenstein. But I have a crushing reply to your argument, such that, once I deliver it, you will at once give up further debate with me on this particular point:
Alas, I don't get modesty credit on this one, because after publishing yesterday's post I realized a similar flaw on my own—this one concerning Occam's Razor and psychic powers:
If beliefs and desires are irreducible and ontologically basic entities, or have an ontologically basic component not covered by existing science, that would make it far more likely that there was an ontological rule governing the interaction of different minds—an interaction which bypassed ordinary "material" means of communication like sound waves, known to existing science.
If naturalism is correct, then there exists a conjugate reductionist model that makes the same predictions as any concrete prediction that any parapsychologist can make about telepathy.
Indeed, if naturalism is correct, the only reason we can conceive of beliefs as "fundamental" is due to lack of self-knowledge of our own neurons—that the peculiar reflective architecture of our own minds exposes the "belief" class but hides the machinery behind it.
Nonetheless, the discovery of information transfer between brains, in the absence of any known material connection between them, is probabilistically a privileged prediction of supernatural models (those that contain ontologically basic mental entities). Just because it is so much simpler in that case to have a new law relating beliefs between different minds, compared to the "boring" model where beliefs are complex constructs of neurons.
The hope of psychic powers arises from treating beliefs and desires as sufficiently fundamental objects that they can have unmediated connections to reality. If beliefs are patterns of neurons made of known material, with inputs given by organs like eyes constructed of known material, and with outputs through muscles constructed of known material, and this seems sufficient to account for all known mental powers of humans, then there's no reason to expect anything more—no reason to postulate additional connections. This is why reductionists don't expect psychic powers. Thus, observing psychic powers would be strong evidence for the supernatural in Richard Carrier's sense.
We have an Occam rule that counts the number of ontologically basic classes and ontologically basic laws in the model, and penalizes the count of entities. If naturalism is correct, then the attempt to count "belief" or the "relation between belief and reality" as a single basic entity, is simply misguided anthropomorphism; we are only tempted to it by a quirk of our brain's internal architecture. But if you just go with that misguided view, then it assigns a much higher probability to psychic powers than does naturalism, because you can implement psychic powers using apparently simpler laws.
Hence the actual discovery of psychic powers would imply that the human-naive Occam rule was in fact better-calibrated than the sophisticated naturalistic Occam rule. It would argue that reductionists had been wrong all along in trying to take apart the brain; that what our minds exposed as a seemingly simple lever, was in fact a simple lever. The naive dualists would have been right from the beginning, which is why their ancient wish would have been enabled to come true.
So telepathy, and the ability to influence events just by wishing at them, and precognition, would all, if discovered, be strong Bayesian evidence in favor of the hypothesis that beliefs are ontologically fundamental. Not logical proof, but strong Bayesian evidence.
If reductionism is correct, then any science-fiction story containing psychic powers, can be output by a system of simple elements (i.e., the story's author's brain); but if we in fact discover psychic powers, that would make it much more probable that events were occurring which could not in fact be described by reductionist models.
Which just goes to say: The existence of psychic powers is a privileged probabilistic assertion of non-reductionist worldviews—they own that advance prediction; they devised it and put it forth, in defiance of reductionist expectations. So by the laws of science, if psychic powers are discovered, non-reductionism wins.
I am therefore confident in dismissing psychic powers as a priori implausible, despite all the claimed experimental evidence in favor of them.
How much could any experimental evidence whatsoever really raise your estimate of psychic powers, given the possibility of 'Matrix' type abilities in a simulation?
If anyone here is interested in psi from a nonskeptic viewpoint, I'd sooner recommend Damien Broderick's "Outside the Gates of Science". (I haven't read it myself, but I don't want to leave you with just Matthew's recommendation.)
If there's an online page with central references and abstracts for allegedly repeatable psi experiments, I'd be interested in glancing through that - fodder for future posts.
dont worry eliezer, no editor in this blog is getting any modesty points either.
But if there are repeatable psi experiments, then why hasn't anyone won the million dollars? (or even passed the relatively easy first round?)
Uh, "The Irreducible Mind" is garbage.
I don't see how you can shrink the number of rules even in the non-reductionist case. You'd need enough rules to describe, not a simple-behaving ontologically basic psychic power (like quantum spooky action at a distance seen by a Copenhagen theorist) but a complex one (like statistically barely noticeable psychokinesis) that does a nearly-perfect imitation of a meat brain, down to the quarks. You have to model the whole of the reductionist case AND the psychic power as well. That's necessarily more entities.
I took psi seriously back when I thought that the scientific method defined rationality. Once I learned about Bayes I realized that the sort of reports of psi that science turns up would be expected if psi isn't real while much more blatant things would be expected if real psi inspired the investigation. I also noticed that priors matter and psi really should be ignored without very large effects based on low priors. Somewhat earlier pre-Bayes psi had blended somewhat into the category "Everything you know is wrong" and loose specific identity as 'psi'. Post-Bayes the "Everything you know is wrong" itself split into a few categories and psi went in the "reason is a mistake" extreme category.
"If the 'boring view' of reality is correct, then you can never predict anything irreducible because you are reducible."
Maybe I missed this yesterday, or in another reductionism post, but doesn't that imply that there is no fundamental level of reality - nothing which is not reducible to something else? It could also be that I'm just not understanding what you mean.
Eliezer, what if psi phenomena are real, but they work through as-yet-unknown laws of physics? In this case reductionism could still be true (and probable), even if psi is real. I can't really see why psi phenomena rule out a reductionist universe (and I guess Damien Broderick agrees...).
By the way, I don't believe in psi, and think that all effects found thus far are based on the misapplication of statistics and related errors.
Pyramid: The point is that sure, that's possible, but we shouldn't bet on that. That is, if we do discover psi is real, without having discovered a reduction for it, then we should increase our belief that the universe has irreducible mental (or mental like) components.
It is not absolute proof. The point is that it actually would be evidence favoring that position. It's not quite obvious to me that it would be strong evidence, but the argument does seem convincing that it would be evidence.
I don't quite see this one. Telepathy and telekinesis would be easy enough to implement via the Matrix or even lesser technologies. Even precognition holds out the possibility of expanding our account of causality to allow loops, which General Relativity occasionally seems to threaten. How is psi on the same order as 2 + 2 = 3, or Jehovah as the one true God of all reality?
The supposed evidence consists of stigmata, hypnotic suggestion, automatic writing, multiple personality disorders, near-death experiences, out-of-body experiences, apparitions, visions, genius level creativity and ecstatic states of consciousness. Since the stated aim is:... (read more)
[...what's that? Foul! Foul! You can't do that! Now I shall have to find a new nit to pick!]
It's not on that level, that's the level which I respond to with the forbidden bet, e.g. p = 0, along with all the other stuff that implies strongly that our concepts of probability are simply broken.
Reason is a mistake for less extreme reasons such as "I'm dreaming" or "I'm a Boltzman Brain" or some forms of "my life is not merely a simulation but a psychological experiment".
The possibility that many "paranormal" or "psi" experiences are caused by undiagnosed or transient temporal lobe disorders should not be overlooked. Epilepsy is still poorly understood, underdiagnosed, and misdiagnosed. These "supernatural" things could be caused by natural but unusual brain states.
Vassar, I don't understand why psi is on that level. Unless you're presuming that someone is telepathically influencing you to make mistakes.
You pretty much said it. Hypotheses suggested by mind-projection priors turning out to be true pretty much refutes Occam and consequentially science.
I considered going anonymous for this because I know I'll be decimated here among you guys, but I decided to be bold because I think it's an argument worth making.
I have a world view that's very similar to many of you here, with reductionism as one of the center pieces.
So now to queue the lamentation and ridicule which I bring willingly: I am a psychic as well.
Many, many wishful people come at this from the fairy tail perspective of wishing paranormal things to exist, and therefore convincing themselves that they do.
I came from an opposite perspective.
I be... (read more)
Ken, I look forward to hearing about your lottery wins.
I hear your cry. I take you seriously and have no interest in insulting you. If you think this is an issue for you, may I suggest you consider a neurologist? Have you ever had a brain scan? There are many kinds of temporal lobe events, and you may benefit from diagnosis and possibly treatment. You may find relief with Tegretol or a similar agent.
Of course you know what your wife is imagining: you know her well and are obviously adept at reading her subconscious facial and body cues. Many of us often know what our friends are thinking, but I assure you ... (read more)
Ken: Do the experiment with your wife repeatedly and see what happens.
Alternately: do you right now have "visions"/guesses/whatever of say, tomorrow? Write down a list of them, say, ten of them. Tomorrow note which were accurate and which were inaccurate.
Alt alt: I have written down on a small piece of paper a four digit number, and underneath this, drawn something. What is the number and what have I drawn? (Alternately, have your wife do that experiment with you a few times)
A few things.
First, I have actually been through a process of diagnosis that I submitted myself to for this very purpose -- to uncover whatever underlying neurological issue I had. They found nothing out of the ordinary, and I function perfectly well. I am well adjusted, not on medication, and otherwise "normal."
Second, comments like Eli's about the lottery aren't fair, because I never claimed to be omniscient, only to have some sort of extra perception.
Imagine a scenario in which the world is filled with deaf people. Human beings have never had ... (read more)
In response to Ken saying a 90% win at Rock Paper Scissors is impossible, Rock Paper Scissors is not a very good test of the statistical significance of psychic powers. Rock Paper Scissors is something of a game of skill, especially when you are a playing against someone you know well that does not intentionally try to predict the other player's thought process. Ken's wife probably had something of a predictable pattern in that game -- maybe she got bored, maybe she subconsciously played poorly to make Ken seem like more of a psychic.
http://www.worldrps.com/ It started as a joke, but it's one of those jokes that became too serious for its own good. I would be very surprised if Ken could consistently beat any of the world's top ranked RPS players.
Ah. Well, I look forward to hearing the news of your lottery wins, then.
@Ken: I am interested in your claim. You can understand that your personal testimony is not really enough to convince, but I will assume that you are posting in good faith and are serious about (dis)proving your psychic abilities to your own satisfaction.
You may wish to attempt the following modification on the rock-paper-scissors experiment: Your wife (or another party) will roll a six-sided die. 1-2, she will throw rock; 3-4, she will throw paper; 5-6, she will throw scissors. In this way, her throw will be entirely random (and so not predictable through... (read more)
See Derren Brown - Paper, Scissors, Stone
Tim, that was fascinating. I don't know how he did it. I certainly don't have a "trick," but of course you can't know that.
Ian: that's a great idea, I'll try it tonight if I have some time. I'll report back honestly. I think I'll be able to perform under those circumstances, but it'll be interesting to see.
First, great blog.
Second, it would be nice to hear back from Ken. I'd like to know if the experiment suggested by Ian yielded any results (even though I think that it could be done much more rigorously than what he's suggested with little additional effort).
Third, I want to raise two points about Eliezer's post:
a) Nothing can raise the probability of something being true if this something isn't logically/mathematically possible. No matter how much evidence we find that apparently supports the claim that there's a logical contradiction in our universe... (read more)
The SF writer Catherine Asaro came up with a workable explanation of empathy/telepathy that doesn't require non-reductionism, though I don't think it's all that plausible; it's based around quantum entanglement between microstructures in the brains of psions in close proximity to one another (and a lot of hand-waving, of course). In her books, psi powers didn't evolve naturally, but were the result of extensive genetic tinkering by aliens with a far more advanced knowledge of genetics, neurology, and quantum physics than humans presently possess, enabling ... (read more)
The conclusion is rather strong one, Eliezer destroys the dreams of millions of people who are reading books about meditation, mind-control and other stuff. But this conclusion is stated at the end of the sequence which was preparing us all the way through - so it is good and gives a good chance to reflect over it.