(urth) 5HC : Skinner, Turing (fwd)

[maru]

Iorwerth Thomas wrote:

> Pretty good.  Here's a possible counterexample (original to a 
> Calvinist cognitive scientist by the name of Donald Mackie - or 
> Mackay; I forget which - via John Barrow's nice little book 
> 'Impossibility').
>
> Let's assume all of the above, plus the not unreasonable - given our 
> present state of knowledge - that these desires correlate with brain 
> states. Let's also (just for fun) assume that the laws of the universe 
> are completely deterministic - no quantum mechanics - and reductionist 
> - all is controlled by the laws of physics with no emergence.  None of 
> these additional assumptions appear to be necessary for this argument, 
> they merely point out how strong it is.
>
> In this hypothetical universe, I have indulged in a little black magic 
> and conjured Laplace's Demon, the bodiless, ominescient intelligence 
> which can predict the actions of everything in the universe.  I have 
> asked you what you wish to have for lunch tomorrow.  I am told that 
> you will, given your brain state now, have a cheese sandwich for lunch 
> tomorrow.
>
> Fine.  If I wait and watch, I will see you eating a cheese sandwich 
> tomorrow.  But what if (loony sorcerer that I am) I _tell_ you what 
> you are going to have to eat tomorrow as soon as I aquire the 
> information?
>
> It transpires that I change your brain state from a) not knowing what 
> I was going to eat tomorrow to b)knowing what I am going to eat 
> tomorrow.  This throws the prediction a little out of whack, so I rush 
> back to my summoning circle and ask the Demon for a new prediction 
> concerning your actions given your present brain state of b).  Which 
> he does.
>
> Enthused, I run back to you and tell you what you are going to eat 
> tomorrow and thus change your brain stait to c) knowing what I'm going 
> to eat tomorrow given I have brain state b).  Which throws the 
> prediction out of whack, so I run back to the Demon and....  etc.
>
> I can't tell you what you're going to do (even if I have perfect 
> knowledge of it) without no possibility of changing what you will do, 
> which removes some of the sting from physical determinism.  Replace 
> 'brain states' with the 'my desires' and, assuming that you're 
> responsive to the environment your desires might well change when 
> you're told what you're going to do (particularly if you tend to 
> desire the frustration of arrogant black magicians who wish to predict 
> the future!).
>
> There are almost certainly a lot of problems with this story, but I'm 
> fond of it.
>
> Iorwerth

Laplace's demon is truly omniscience no?
Then he knows you are going to tell me, and has factored that in.
He will also know that you will ask for an updated prediction.
That too will be foreseen by his omniscience right?
Furthermore, he will see you scurrying back to tell me.
But, omniscient being he is, he can see how many times you will be able to
upset the temporary equilibrium of my desires, and indeed, when I will 
begin to ignore
you (or ask what you are smoking and how can I synthesize suma that?).
That number being finite, he can easily  work out what my final desires 
will be, and give the answer
which will both start the sequence and end it.
Even better, in a deterministic universe like this, to the Demon, the 
only unkown will be himself.
So he can easily choose how he will perturb the universe, and make his 
predictions on that basis
or self-fulfilling.
If this is an argument, seems more like one against omnisicence.

~Maru