Re: adult vs. child

From: Bruno Marchal <>
Date: Wed, 11 Feb 2009 09:47:48 +0100

On 10 Feb 2009, at 20:11, Brent Meeker wrote:

> Bruno Marchal wrote:
>> On 10 Feb 2009, at 18:44, Brent Meeker wrote:
>>> Stathis Papaioannou wrote:
>>>> 2009/2/10 Jack Mallah <>:
>>>>> This sort of talk about "random sampling" and "luck" is misleading
>>>>> and is exactly why I broke down the roles of effective probability
>>>>> into the four categories I did in the paper.
>>>>> If you are considering future versions of yourself, in the MWI
>>>>> sense, there is no randomness involved. Depending on how you
>>>>> define "you", "you" will either be all of them, or "you" are just
>>>>> an observer-moment and can consider them to be "other people".
>>>>> Regardless of definitions, this case calls for the use of Caring
>>>>> Measure for decision making.
>>>> It seems that the disagreement may be one about personal
>>>> identity. It
>>>> is not clear to me from your paper whether you accept what Derek
>>>> Parfit calls the "reductionist" theory of personal identity.
>>>> Consider
>>>> the following experiment:
>>>> There are two consecutive periods of consciousness, A and B, in
>>>> which
>>>> you are an observer in a virtual reality program. A is your
>>>> experiences between 5:00 PM and 5:01 PM while B is your experiences
>>>> between 5:01 PM and 5:02 PM, subjective time. A is being
>>>> implemented
>>>> in parallel on two computers MA1 and MA2, so that there are
>>>> actually
>>>> two qualitatively identical streams of consciousness which we can
>>>> call
>>>> A1 and A2. At the end of the subjective minute, data is saved to
>>>> disk
>>>> and both MA1 and MA2 are switched off. An external operator picks
>>>> up a
>>>> copy of the saved data, walks over to a third computer MB, loads
>>>> the
>>>> data and starts up the program. After another subjective minute
>>>> MB is
>>>> switched off and the experiment ends.
>>>> As the observer you know all this information, and you look at the
>>>> clock and see that it is 5:00 PM. What can you conclude from this
>>>> and
>>>> what should you expect? To me, it seems that you must conclude that
>>>> you are currently either A1 or A2, and that in one minute you
>>>> will be
>>>> B, with 100% certainty. Would you say something else?
>>> I might say that while there are two computations, there is only one
>>> "stream of consciousness".
>> You are right, but I think that Stathis is right too. When Stathis
>> talks about two identical stream of consciousness, he make perhaps
>> just a little abuse of language, which seems to me quite justifiable.
>> Just give a mirror to the observer so that A *can* (but does not)
>> look
>> in the mirror to see if he is implemented by MA1 or by MA2. Knowing
>> the protocol the observer can predict that IF he look at the mirror
>> the stream of consciousness will bifurcate into A1 and A2.
> I don't follow that. If A1 looks in the "mirror" and sees A2, then,
> ex
> hypothesi, A2 looks in the "mirror" and sees A1 and the two streams of
> consciousness remain identical.

I don't understand what you mean by A1 sees A2. I guess we have a
misunderstanding, and I have probably be not clear.
When A1 looks at itself in the third person way, he discovers is most
probable "running universal machine", which is MA1. So the stream of
consciousness differentiate at this point. Mallah get the correct
probability here.

> If consciousness is computation, independent of
> physical implementation, then computations that differ only in
> their physical
> realizations are identical and cannot be counted as more than one.

But what we call the "physical implementations" is a sum on all
possible computations going through the relevant states. The measure
has to be taken on all computational histories exactly because the
stream of consciousness is the same for all those computational


> Brent
>> Accepting
>> the Y = II rule, that is bifurcation of "future" = differentiation of
>> the whole story) makes the Stathis "abuse of language" an acceptable
>> way to describe the picture. So Stathis get the correct expectation,
>> despite the first person ambiguity in "two identical stream of
>> consciousness".
>> If two infinitely computations *never* differentiate, should we count
>> them as one? I am not sure but I think we should still differentiate
>> them. UD generates infinitely often such infinitely similar streams.
>> That should play a role for the relative (to observer-moment) measure
>> pertaining on the computations. OK?
>> Bruno
> >

You received this message because you are subscribed to the Google Groups "Everything List" group.
To post to this group, send email to
To unsubscribe from this group, send email to
For more options, visit this group at
Received on Wed Feb 11 2009 - 03:47:51 PST

This archive was generated by hypermail 2.3.0 : Fri Feb 16 2018 - 13:20:15 PST