Re: Causality and consciousness

From: Marchal <>
Date: Mon Jan 25 03:04:16 1999

Hal wrote :

>If we accept that consciousness is a real phenomenon deserving of
>explanation, this view would require that causality is also a real,
>fundamental, physical phenomenon. But if the only way causality can be
>defined is as a relationship that spans multiple universes, it would
>follow that consciousness also must fundamentally involve multiple

I don't agree with the idea of equating real phenomenon with physical
Nevertheless I do agree with the fact that consciousness fundamentally
involve multiple "universes".
I put "universe" in quote", because I don't understand the word. In the
context of mechanism or computationnalism (COMP), consciousness involve
multiple computationnal histories. In that setting, a "universe" is just
a bundle of (probably very deep in Bennett sense ; see Li & Vitanyi)
computationnal histories viewed from inside. See my work
( for an attempt toward a rigorous
definition of "view from inside".

Hal wrote :
>This is not necessarily as absurd as it may seem at first. Our
>consciousness seems to inherently be an active process. The sense we
>have of being conscious is intricately bound up with the sensation of
>the passage of time. Yet time "passing" is really a matter of the
>increase of entropy, which can also be related to universe splitting
>in either a many-worlds or all-universes model. So it is already clear
>that our perceptions do partake of some aspects of the multiple worlds.
>If we could somehow bring counterfactuals into this, then we might be
>closer to a coherent theory of consciousness.

I cannot over-emphasize the importance of what Hal is saying here.
In ( I give more than one hint how
bringing counterfactuals into this.
The "ultimate goal" is linking precisely conterfactuals and the
(conditionnal) measure on the (relative) computationnal histories.
This need to be done for solving the mind body problem with COMP.
Important related work are "Counterfactuals" by David Lewis, "Inquiry" by
Stalnaker, a paper by Hardegree 1976 which shows a formal relation
between Quantum Logic and the logic of Counterfactuals in Stalnaker
sense, a new approach to Quantum Logic by the mathematician J. L. Bell
1986 (not the physicist J. S. Bell !).
See also Isham C.J. 1994 on Quantum Logic and the Histories Approach to
Quantum Theory.
Except for Lewis, the reference are in my thesis

Hall wrote :

>Jacques also makes another point, which I find somewhat questionable but
>which may be valid:
> - Our current conscious experiences can be taken to be "typical" in
> that they are drawn randomly from the set of all of "our" conscious
> experiences, over all the universes.
>I question this for a couple of reasons:
> - This is similar in flavor to the Carter-Leslie "Doomsday" argument which
> says that we are typical specimens from the entire history of our race,
> and hence the human race is likely going to die out in a few hundred
> years. This argument is not at all well accepted among philosophers.
> - In the MWI example, it's not clear whether I should be a random sample
> among all instances of "me", or perhaps I should be a random sample
> among all conscious observers in all the universes, human, alien, or
> other. It seems harder to draw conclusions in the latter case.
>Jacques has suggested that if you were going to live forever, this last
>argument would predict that you would already find yourself very old
>(exactly what is predicted with regard to the human race in the Doomsday
>argument). However if we assume that the measure of those branches in
>which you live forever is small (as it almost surely would be), then
>in fact the observation that you are relatively young is consistent with
>there being branches where you will live forever.

I think there is no meaning in statement involving the (absolute)
probability of being myself. There are only conditionnal probabilities of
living such histories knowing for sure I am living such history. Even if
we are willing to give meaning to absolute "probability of being me" the
doomsday argument is simply wrong in the MWI. By the way, Leslie uses
explicitely his doomsday argument against Everett MWI, in his book


 | Bruno MARCHAL Phone : +32 (0)2 6502711 |
 | Universite Libre de Bruxelles Fax : +32 (0)2 6502715 |
 | Prive : +32 (0)2 3439666 |
 | Avenue F.D. Roosevelt, 50 |
 | IRIDIA, CP 194/6 |
 | B-1050 BRUSSELS Email : |
 | Belgium URL : |
Received on Mon Jan 25 1999 - 03:04:16 PST

This archive was generated by hypermail 2.3.0 : Fri Feb 16 2018 - 13:20:06 PST