I just wanted to highlight a claim made by Simon4, (since it seemed more appropriate to discuss it here than do thread necromancy).
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, we should still believe that the claim is false and continue to look for the truth.
We're sometimes wrong about what's logically impossible! The scientific community seemed to have a pretty good reaction to the OPERA data, which was to say, "We think it's really really likely that these data are in error, as they seem to be logically impossible in our current logical frameworks, but this raises the probability enough that we thing it's worth actually checking to see how they made this almost-certainly-an-error. Plus, it'd be good to fix the problem and have more accurate readings in the future."
Inside the argument: Sure, if something is logically impossible, nothing can raise its probability.
Outside the argument: What is our certaintly that we didn't make any mistake while concluding that X is impossible? Less than 100%, I suppose.
Reductionist lines of thinking have made countless predictions that have all been verified. Psychic phenomena would be -one- prediction of a non-reductionist line of thinking. It is more likely that non-reductionist lines of thinking predicted the right result for the wrong reasons than that reductionism is wrong.
Reductionist lines of thinking have made countless predictions that have all been verified.
And even more that turned out to be wrong.
Granted. But they didn't turn out to be wrong for non-reductionist reasons; indeed, they were proven wrong within the context of reductionism, which might be even better proof of the usefulness of reductionism than the ideas it has gotten right.
ETA: I don't think reductionism is right; I don't think the concept of "right" can reasonably apply to reductionism, although certainly the concept of "wrong" could. It is a model of the universe, and one which is, at least with the present evidence, isomorphic with any accurate model of the universe.
Nitpick: There is only lack of evidence for a force which only interacts between brains There is already precedent for an event on one scale to change the total force exerted on that scale: the mass change of atomic reactions, resulting in a change in the amount of gravity exerted by a closed system with no energy transfer.
If there is also a force exerted by brains or on brains that is different from that exerted on the same number of brain cells that are not brains, analogous to the force exerted by atoms which is different from the force exerted by the same number of protons, neutrons, and electrons that are not atoms, then physic phenomena.
I don't think that psychic phenomena have been demonstrated to be more likely than hallucinations, but I don't think they would be as strong evidence against reductionism as is suggested- but they would be very strong evidence that our current reductionist models are incomplete.
Today's post, Psychic Powers was originally published on 12 September 2008. A summary (taken from the LW wiki):
Some of the previous post was incorrect. Psychic powers, if indeed they were ever discovered, would actually be strong evidence in favor of non-reductionism.
Discuss the post here (rather than in the comments to the original post).
This post is part of the Rerunning the Sequences series, where we'll be going through Eliezer Yudkowsky's old posts in order so that people who are interested can (re-)read and discuss them. The previous post was Excluding the Supernatural, and you can use the sequence_reruns tag or rss feed to follow the rest of the series.
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