From: frank@D012S658.uucp (Frank O'Dwyer)
Newsgroups: alt.atheism
Subject: Re: contradictory nature of free will and omni-anything
Date: 28 Jan 1993 15:45:49 GMT
Organization: Siemens-Nixdorf AG
Distribution: world
NNTP-Posting-Host: d012s658.ap.mchp.sni.de

In article <1k6nugINNqpf@srvr1.engin.umich.edu> ingles@engin.umich.edu (Ray Ingles) writes:
#In article <1k69nkINNd21@horus.ap.mchp.sni.de> odwyer@sse.ie writes:

#>#>I think free-will is an illusion.  There's also a difference between being
#>#>determined and being predictable, as I will try to show.  In the following
***********IMPORTANT*******
#>#>I use the term "computer" to mean "hardware + software".
***********IMPORTANT*******

See?  I know you didn't write this, but it's certainly more descriptive
of an actual computer that sits on your desk than it is of an abstraction
such as a Turing machine.

#>#>
#>#>A computer's behaviour is entirely determined (ignoring quantum effects for
#>#>the moment).  It's progression from one state to the next is hard-wired.
#>
#>No. If I stand beside your computer flicking the on/off switch, what sense
#>is there in what you say? You are viewing the computer as a closed system.
#>Nice try - but this closed system isn't the universe. Look what it's doing 
#>to the laws of thermodynamics. It has a funny idea of gravity too.
#
# The 'halting problem' which Norman refers to below strictly applies to
#'Turing machines' which are conceptual computers invented to think about
#certain problems in computability.

Sure. But the *computer* = h/w + s/w I refer to *above* is a physical
thing. I can turn it on and off.

[desc. of Turing m/c deleted]

#>#>However, it is impossible to _predict_ what a given computer will do.  If
#>#>you want to find out, you have to let it run, and wait for it to finish.
#>#>(This is the basis of the halting problem: you can't even predict whether
#>#>any given computer will halt or not.)
#>
#>True. If it were determined, it would still be unpredictable.  But you
#>have yet to show that even a computer's behaviour is determined.
#
#***********IMPORTANT IMPORTANT IMPORTANT IMPORTANT IMPORTANT***********
#># Well, in *practice*, yes, things may not be predictable. But in principle
#>#they need not be unpredictable.
#***********IMPORTANT IMPORTANT IMPORTANT IMPORTANT IMPORTANT***********
#
# Do you understand my point now? Norman (as far as I can tell) had
#incorrectly understood the 'halting problem' to state that there was no
#way to tell if a deterministic computer would halt. I was explaining that
#the 'halting problem' merely stated that there was no *algorithm* or
#general procedure for deciding if a given 'Turing machine' would halt.

I am aware of the halting problem and its scope.  My point is that
it is in general impossible to distinguish between something 
which is 'in principle' predictable and something which is _in fact_ 
_unpredictable_. Therefore the distinction is not useful, especially where
free will is concerned. Until somebody can consistently predict with close 
to 100% accuracy what I'm going to do at any given moment, I'm going to keep 
thinking I've got free will.

[deletia]
#>This is akin to the belief that one day science will explain everything
#>in the universe.
#
# No, No, No, No, No, No, No, No, No, No, No, No, No, No, No.
# I was saying, for *a particular case*, that one might be able to decide
#if it would halt or not. I did *not* (repeat: not) say that eventually
#an answer would be found for all cases. Clear?

O.K., apologies - though I suspect the original poster was of this
belief.

#>                 How do you distinguish an infinite procedure from one
#>which is going to terminate in the next second.  How long will you wait 
#>before you hit the abort key?
#>[...]
#
# The part you deleted gave an example. The Turing machine with one command:
#"Halt." I can know if that one will halt; in fact, it will. For any one
#specific case, it may be possible to figure out if the Turing machine
#that represents that problem will halt. But there is no general algorithm
#that can do that. (If you *really* want, I can tell you the proof.)

I don't see how this relates to the original assertion - that determined
doesn't imply predictable.  In a case where you are *in practice* unable
to predict a computer's result,  how long do you wait before you
infer that it's result is _in fact_ not predictable?

#># Also, what if we run the same program on two computers, but one is faster
#>#than the other? If the faster one stops, we can know that the slower one
#>#will stop.
#>
#>Unless it blows up. Or I spill coffee on the disk. Or I trip on the power
#>cord. Dashed unpredictable these users - something about free will...
#
# As explained above, WE ARE TALKING ABOUT ABSTRACT THEORETICAL ENTITIES,
#NOT SPECIFIC ACTUAL COMPUTERS THAT YOU COULD PUT ON YOUR DESK.

The ones with h/w and s/w?

# Ray Ingles               ingles@engin.umich.edu
Newsgroups: alt.atheism