RE: Decision theory

From: Higgo James <>
Date: Wed, 6 Jan 1999 14:06:42 -0000

Interesting concept concerning the infnitely small. How about the more
orthodox idea that the brain is a quantum computer (running things like
Shor's and Grover's algorithms), relying on an infinite number of parallel

> -----Original Message-----
> From: Jacques Bailhache []
> Sent: 04 January 1999 16:26
> To:; Jacques M Mallah; 'Wei Dai'
> Cc: 'Marchal';;;
> Subject: Re: Decision theory
> Jacques M Mallah wrote:
> >In fact, the whole concept
> >of free will never made any sense. The only possibilities are
> determinism
> >and randomness, neither of which allows any 'decisions'.
> I wonder if there couldn't be another possibility, neither determinism,
> nor
> randomness, but free will, which I agree to be something rather
> mysterious.
> >At one level of description I can describe a process as a physical system
> >evolving in time according to the laws of mechanics; at another level, I
> >can describe it as a computer, following a certain algorithm, without
> >getting into physical details; at another level, I can describe it as a
> >person making a decision, without getting into algorithmic details.
> This idea of description levels seems very important to me. This is
> perhaps
> the key idea for understanding the spirit and its properties,
> consciousness,
> free will and creative intelligence.
> My idea is that the universe, and the living beings in particular, could
> be
> made of an infinity of material organization levels : body, cell,
> molecule,
> atom, particle, quark, ..., with different physical laws at each level. In
> this case a human being cannot be considered as a finite machine, since
> he's
> infinite in the infinitely small. Any physical theory is only
> approximation
> of the physical reality. In fact, the physical reality could be just an
> infinite mathematical theory, defined by an infinite converging sequence
> of
> finite theories. In this model, the spirit would be relative to the
> considered level : if X1 is not explained by some theory T1, then X1
> belongs
> to the domain of spirit relatively to this theory T1. But there exist a
> more
> precise theory T2 which explains X1. Then X1 belongs to the domain of
> matter
> according to T2. But there exist another X2 which T2 does not explain, and
> which belongs to spirit relatively to T2. But there exist a more precise
> theory T3 which explains X2, and so on... Spirit would be something
> tending
> to nothing without reaching it.
> See also
> I see also an analogy with Feferman's transfinite iteration of the
> reflection principle on formal systems : for a theory T0, there exist a
> Godel proposition G0 which is true but not provable in T0. But by adding
> reflection to T0 we can obtain a more complete theory T1 in which G0 is
> probable. But T1 is itself a finite theory, and we can construct another
> G1
> which is true but not provable in T1, and so on...
> Adding reflection is a mechanical construct, but this leads to an infinite
> sequence T0, T1, T2... which we can integrate in one theory Tw (w =
> omega),
> and we can go on with Tw+1... giving a transfinite sequence of theories.
> Generating the sequence of transfinite ordinals is a creative, not
> mechanizable process, which requires creative intelligence to perceive
> regularities when we fall in a loop, to skip out of the loop.
> See also
> >On Thu, 31 Dec 1998, Jacques Bailhache wrote:
> (...)
> >> If MWI is true and if every possible decision is made in one universe,
> it
> is
> >> clear that the concept of decision has no sense. This leads to the
> collapse
> >> of ethics.
> >
> > The above paragraph makes no sense to me.
> I meant that a decision is significant if it consists in chosing to act in
> a
> certain way which makes real a certain state of the world, excluding other
> states led by other possible (but not actualized) acts.
> If every possible decision is made in one world, there is no real decision
> in this sense. It does not make sense to ask ourself which decision we
> should take to obtain a state of the world which we consider as good if
> anyway every possible decision is taken in some world and then every
> possible state of the world is real is one world.
> > This is the part that got me riled up. Pascal's bet is the height
> >of stupidity. I'd rather live as an atheist and go to hell than spend an
> >eternity kissing up to a god so evil and self centered that he'd send me
> >to hell just for not believing in him when I had no evidence.
> The subject of Pascal's Bet is not whether an eternity in Paradise is a
> good
> thing or not, it's that supposing it has an infinite value, then for any
> probability p that we will spend an infinite time in Paradise if we behave
> well, the corresponding value (infinite times a finite probability) is
> infinite. But you're right in the sense that Pascal forgot that there is
> also a (rather strange) possibility that we suffer for an infinite time if
> we behave well. Suppose this has probability p'. Then the value of
> behaving
> well would be (p - p') * infinite. In fact we should behave well only if
> we
> believe that p > p'.
> Concerning decision theory, it's not exactly the same situation :
> Let P be the proposition : "Decisions has no sense" (for example if MWI is
> true or if everything is predeterminated), and suppose P has probability p
> to be true, according to our knowledge of the world.
> Let A be the choice of acting as if decisions make sense, and B as it does
> not.
> This leads to 4 possibilities :
> ~P, A : Decisions make sense and know it, I take them knowing it make
> sense,
> trying to take the correct decision. This situation has a positive value
> v.
> P, A : Decisions does not make sense, but I think they do. I do not really
> have the choice of thinking decisions make sense or not. At the global
> level, everythink is determinated. No good, no bad, all that can happen
> happens. I would attribute a value 0 to this situation.
> ~P, B : Decision make sense, but I am convinced thai in fact they don't.
> This is the catastrophic situation. I don't make any effort to take the
> correct decision, thinking it does not make sense.This situation has a
> negative value -v'.
> P, B : Decisions does not make sense and I know it, and I don't have the
> possibility of thinking anything else. This situation has also the value
> 0.
> In summary, taking in account the probabilities, choice A has value (1-p)
> *
> v + p * 0 = (1-p) * v, and choice B has value (1-p) * (-v') + p * 0 = -
> (1-p) * v'.
> For any p, the value of A is greater than the value of B, then we should
> chose A.
> Wei Dai wrote:
> >I think you're suggesting that we think of decisions as selecting which
> of
> >the you-like beings is really you, instead of as changing the universe
> >somehow. This seems like a promising approach, and I've tried it too, but
> >I haven't figured out how it can be formalized. It may require a
> >different formal framework from "classical" decison theory.
> I agree. See
> Jacques M Mallah wrote:
> > I'll say it again: my mental processes *are* the laws of physics
> >in action, and *do* have consequences. My choice *does determine* the
> >actual utility, which is to say, the laws of physics determine it.
> Interesting idea. But these laws of physics should be infinite if we are
> not
> machines.
> ==========================
> Jacques Bailhache
> Y2K Centre of Expertise (BRO)
> DTN: 856 ext. 7662
> Tel: +32-2 729.7662, Fax: +32-2 729.7985
> Email:
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Received on Wed Jan 06 1999 - 06:12:13 PST

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