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Kingreaper comments on How to Convince Me That 2 + 2 = 3 - Less Wrong

53 Post author: Eliezer_Yudkowsky 27 September 2007 11:00PM

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Comment author: Kingreaper 26 November 2010 01:39:33AM 0 points [-]

Upon suddenly discovering that the whole world looks different this morning than it did last night is the rational belief "I guess I was deluded for my whole life up to this point" or "I guess I'm deluded now"?

Considering the fact that you're not waking up in a mental institution, but the world still seems to contain them (and if you get 2 sets of 2 of them, you have 3); the latter is a much more likely situation

Comment author: orthonormal 27 November 2010 10:57:43PM 0 points [-]

You're neglecting the hypothesis "my memories of the past are being distorted to convince me that 2 and 2 make 4 instead of 3". Given how easily we distort our memories under conditions of sanity, this is as likely as "I'm deluded now".

Comment author: Kingreaper 28 November 2010 12:08:32PM *  0 points [-]

If you suddenly gain a set of memories indicating that the raptor conspiracy is taking over the world, you would be considered deluded.

If you suddenly gain a set of memories indicating that 2+2 equals something other than what it DOES in fact equal, you are likewise deluded.

So your suggestion is in fact a subset of being deluded*. At which point you should voluntarily seek out psychological/psychiatric help.

  • (which I assign a low probability, as I have never heard of such a type of delusion existing)

If you believe (as you seem to suggest by use of the aactive rather than the passive voice) that this delusion is being deliberately induced, it is important to remember that anyone with the power to induce that delusion could also reduce you to a gibbering wreck; and hence that going to get help is highly unlikely to be "part of their plan".

Comment author: orthonormal 28 November 2010 08:58:11PM 0 points [-]

This is a distraction from the actual point; of course if this happened to me, then my first priority would be getting help (I might be having a stroke, for instance). But once I'm at the hospital and they tell me that I'm all right, but something strange happened to my brain so that it falsely remembers 2 and 2 having made 4, instead of the obviously correct 3...

If you don't agree that some set of circumstances like this should conspire to make me rationally accept 2+2=3, then if the scenario happened to you (with 3 and 4 reversed), you're asserting that you could never rationally recover from that metal event. Since I'd prefer, should I go through a hallucination that 2 and 2 always made 3, to be able to recover given enough evidence, I have to take the "risk" of being convinced of something false, in a world where events conspired against me just so.

Comment author: wedrifid 28 November 2010 12:21:16PM *  2 points [-]

Upon suddenly discovering that the whole world looks different this morning than it did last night is the rational belief "I guess I was deluded for my whole life up to this point" or "I guess I'm deluded now"?

Why completely leave out the possibility that you aren't deluded at all? Depending on just what kind of 'different' you wake up in that is a distinct possibility.

I would, by the way, start with a high prior for 'deluded now' which would be altered one way or the other by extensive reality testing. I experience that in dreams all the time. I know from personal experience it is easier for me to be confused about the transient sensory experience of the present than the broad structure of all my memories. Results may vary somewhat.

Comment author: Kingreaper 28 November 2010 01:55:03PM *  0 points [-]

Good point, in the case of waking up in a logically possible world, remembering a previous logically possible world, there is a non-zero possibility that you've actually gone from one to the other somehow. How low the probability is depends on the nature of the differences

I was too caught up in the case of waking up in a world where the world you remember is logically impossible.

Comment author: wedrifid 29 November 2010 12:27:23AM *  0 points [-]

Good point, in the case of waking up in a logically possible world, remembering a previous logically possible world, there is a non-zero possibility that you've actually gone from one to the other somehow. How low the probability is depends on the nature of the differences

Exactly. And with slightly different wording a world in which it seems like you have changed from one logical world to another is itself a just a logically possible world.

I was too caught up in the case of waking up in a world where the world you remember is logically impossible.

That would be awkward! It would require an awful lot of reality testing on the question of just how logically impossible things were. Even after that your confidence in just about anything would be fubared.