[extropy-chat] A New Year's gift for Bayesians

[Eliezer S. Yudkowsky]

Robin Hanson wrote:
> At 12:03 AM 1/1/2005, Eliezer Yudkowsky wrote:
> 
>> Laplace takes every event in your life, and every probability you 
>> assigned to each event, and multiplies all the probabilities together. 
>> This is your Final Judgment - the probability you assigned to your 
>> life. ...
>> Er, well, except that you could commit suicide when you turned five, 
>> thereby preventing your Final Judgment from decreasing any further. Or 
>> if we patch a new sin onto the utility function, enjoining against 
>> suicide, you could flee from mystery, avoiding all situations in which 
>> you thought you might not know everything. So much for that religion.
> 
> Saint Laplace should instead extrapolate your probabilities and assign 
> them to all events that happen, regardless of whether you learn about 
> them.  Then you won't want to commit suicide, etc.

(thinks)

All events that actually happen, everywhere in the (any?) universe... 
hm.  That sounds fair.  But what about conditional probabilities?  In 
what order is the Judged soul's judgment over all events extrapolated? 
In a single life, the linear ordering is obvious, even when we evaluate 
the conditional likelihood of other possible outcomes for any single 
branch.  If we are to evaluate all events in the universe, how do we 
compute the joint probability of all those events together?

-- 
Eliezer S. Yudkowsky                          http://singinst.org/
Research Fellow, Singularity Institute for Artificial Intelligence