[skissane]

A lot of people connect idealism with psychic powers, and some even view that as counterargument against idealism. The basic idea seems to be this: (1) I have full control over the contents of my own mind, but very limited control over external reality; (2) but, if idealism is true, then external reality is part of my own mind, so I have full control over it too; (3) therefore, psychic/miraculous powers exist; (4) but, (3) is clearly false, therefore idealism must be false. People who want to believe in the psychic/paranormal/miraculous/etc stop the argument at (3), people who don't and are looking to use this as an anti-idealist argument go on to (4).

But, I think (1) is false. We actually have far less control over the contents of our own minds than many of us think we do. Anyone who has ever struggled with mental illness or addiction knows this fact very well. But, even for people who are thankfully unaffected by either: how much of our choices are truly "free", and how much are they predetermined by our genetics and by social/cultural influences? We don't know for sure, but probably a lot more than many people assume. And if (1) is false, the whole argument falls apart.

A lot of what you are saying seems to be rather adjacent to this line of argument. I don't agree that idealism makes the psychic/miraculous "more likely". I agree they are possible under idealism – but they are possible under materialism too. It may so happen that the laws of this universe, insofar as we know them, don't permit psychic powers or miracles – but, that's a consequence of what those laws happen to be, not of materialism in itself, and materialism could be just as true even with very different laws of physics which did permit psychic powers and miracles and magic and so forth.

Furthermore, the known laws of physics actually do permit all those things, with unimaginably low (but non-zero) probability – quantum tunnelling, quantum fluctuations, thermal fluctuations, etc, permit just about anything imaginable to happen (or at least appear to happen, in a way which nobody could distinguish from them actually happening), with unimaginably small yet still non-zero (and non-infinitesimal) probability. But, in a spatiotemporally infinite universe, any event with non-zero probability (however remote) will almost surely eventually happen, somewhere and somewhen, even an infinite number of times; indeed, in a spatially infinite universe, every non-zero probability event is almost surely happening somewhere right now, even an infinite number of times simultaneously – including your scenario. And people call idealism crazy–is materialism really any better? At least idealists can say "we have no reason to believe the universe actually exists beyond its observable limits", thereby avoiding the threat of a spatially infinite universe in which every possible event almost surely is happening somewhere right now – that way of avoiding the threat comes naturally to (some versions of) idealism, it is much more arbitrary for a materialist.

[hnfong]

Interesting you bring probability up. Nobody knows where these probabilities come from -- we know how to calculate it and make predictions for sure, but we don't know where they fundamentally come from.

That said, even though you say materialism permits pretty much anything, the probabilities are supposed to be radically different. Materialism predicts that "Jesus" is practically impossible, and some versions of idealism suggests it is a dime a dozen. It seems reality is probably somewhere in between.

My personal theory is that the universe pretends as if it is materialistic by fudging with probabilities. (and also with limits of computations in the sense that if you can't practically solve a computation problem the answer may not actually exist in the same sense as observable limits you mentioned)

[skissane]

> Materialism predicts that "Jesus" is practically impossible,

That's not a prediction of materialism itself, that's a prediction of materialism combined with natural science as we know it. In some parallel universe (a popular speculation among contemporary physicists), for all we know, the laws of physics might have been sufficiently different to make "Jesus" "practically possible". Such a universe would have rather different laws of physics to those we observe here, but if materialism is right about the nature of this universe, it would be just as right about the nature of that one too.

And, I'm not sure if "Jesus is practically impossible" is even a prediction of natural science as we know it. I mean, of course, the odds of "Jesus" happening here-and-now by science alone are hyper-astronomically low–something I doubt any Christian would deny; but just make the universe/multiverse big enough, and the odds that "Jesus" happens sometime, some place, even right now, becomes arbitrarily close to 1. "Jesus" is happening "right now" some light years away (within a googolplex or so). If many worlds is true, there are many branches of the wave function in which "Jesus" really happened, about 2000 years ago, in the ancient Roman province of Judea, even if we have to say they are vastly outnumbered by those in which it didn't but people falsely believed it did. Given materialism, and certain assumptions about parallel universes, the central claims of Christianity actually are true, somewhere, even if not here. And, that's not true of Christianity, but of every other religion too. It isn't "impossible", given those assumptions it is almost certainly true; and it isn't clear what work "practically" is doing. Claims about what happened 2000 years ago aren't "practically" anything, and what difference does it make whether it really happened in this universe or in another one?

> and some versions of idealism suggests it is a dime a dozen.

Whether "Jesus" is impossible (just "practically" or even absolutely), or "a dime a dozen"–isn't in my view anything to do with materialism or idealism in itself. There are idealisms in which "Jesus" is impossible, and there are materialisms in which "Jesus" happens, even an infinite number of times, even an infinite number of times right now (and every other moment too).

That said, most idealisms don't really have anything to say about this issue either way.

[hnfong]

My intuition is that the "evidence" (i.e. traditional ancient texts describing "magic") do not seem to permit relying on purely materialistic mechanisms, and most seem to require some kind of mind-fu to work.

I think otherwise I broadly agree with your observations.

[skissane]

> My intuition is that the "evidence" (i.e. traditional ancient texts describing "magic") do not seem to permit relying on purely materialistic mechanisms,

Contemporary debates about materialism-vs-dualism-vs-idealism originate in 17th and 18th century Europe. I wouldn't assume that ancient texts had any particular opinion on that debate, because they pre-existed that trichotomy.

It is true there are some ancient views which are seen as forerunners of modern materialism – the Cārvāka school in ancient India, the ancient Greek atomists. However, it may be a mistake to simply identify their views with modern materialism, since they arose in a very different context. In any event, many of these ancient and mediaeval religious/magical/etc texts ignored (or were ignorant of) those proto-materialist positions rather than condemning them, so I'm not sure why we should take those texts as taking any particular stance on them. For example, there is no evidence that the authors of the Christian Gospels were aware of the works of Leucippus, Democritus, Epicurus and Lucretius, so why should we interpret the Christian Gospels as contradicting them. I do know that some later Jewish and Christian sources did attack the Greek atomist tradition, but most of those attacks was focused on their (effective) atheism and positions on moral issues, rather than their "materialism" per se.

> and most seem to require some kind of mind-fu to work.

"Mind-fu" is not incompatible with materialism. Maybe, on some distant planet, there is a humanoid species who communicate telepathically via radio waves. Maybe, they even exhibit some form of psychokinetic powers, through a biological ability to manipulate magnetism or (anti-)gravity or some undiscovered physical force. Even if that isn't permitted by physics as we know it, maybe there is some physics we don't know that does permit it. Even if that isn't permitted by the physics of this universe (known or unknown), maybe there is some parallel universe with different physics that does permit it. If the materialists are right and this universe is indeed "material", why wouldn't that other universe equally be so?