# DanArmak comments on Problematic Problems for TDT - Less Wrong

34 29 May 2012 03:41PM

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Comment author: 28 May 2012 04:26:18PM 0 points [-]

We should take this seriously: a problem that cannot be instantiated in the physical world should not affect our choice of decision theory.

Before I dig myself in deeper, what does existing wisdom say? What is a practical possible way of implementing Newcomb's problem? For instance, simulation is eminently practical as long as Omega knows enough about the agent being simulated. OTOH, macro quantum enganglement of an arbitrary agent's arbitrary physical instantiation with a box prepared by Omega doesn't sound practical to me, but maybe I'm just swayed by increduilty. What do the experts say? (Including you if you're an expert, obviously.)

Comment author: 28 May 2012 04:37:15PM *  -1 points [-]

cannot

0 is not a probability, and even tiny probabilities can give rise to Pascal's mugging.

Unless your utility function is bounded.

Comment author: 28 May 2012 04:58:12PM 1 point [-]

0 is not a probability, and even tiny probabilities can give rise to Pascal's mugging.

Even? I'd go as far as to say only. Non-tiny probabilities aren't Pascal's muggings. They are just expected utility calculations. </lighthearted nitpick!>

Comment author: 28 May 2012 05:02:37PM 0 points [-]

If a problem statement has an internal logical contradiction, there is still a tiny probability that I and everyone else are getting it wrong, due to corrupted hardware or a common misconception about logic or pure chance, and the problem can still be instantiated. But it's so small that I shouldn't give it preferential consideration over other things I might be wrong about, like the nonexistence of a punishing god or that the food I'm served at the restaraunt today is poisoned.

Either of those if true could trump any other (actual) considerations in my actual utility function. The first would make me obey religious strictures to get to heaven. The second threatens death if I eat the food. But I ignore both due to symmetry in the first case (the way to defeat Pascal's wager in general) and to trusting my estimation of the probability of the danger in the second (ordinary expected utility reasoning).

AFAICS both apply to considering an apparently self-contradictory problem statement as really not possible with effective probability zero. I might be misunderstanding things so much that it really is possible, but I might also be misunderstanding things so much that the book I read yesterday about the history of Africa really contained a fascinating new decision theory I must adopt or be doomed by Omega.

All this seems to me to fail due to standard reasoning about Pascal's mugging. What am I missing?

Comment author: 28 May 2012 06:16:50PM 0 points [-]

If a problem statement has an internal logical contradiction

AFAIK Newcomb's dilemma does not logically contradict itself, it just contradict the physical law that causality cannot go backwards in time.

Comment author: 28 May 2012 06:23:57PM *  1 point [-]

AFAIK Newcomb's dilemma does not logically contradict itself, it just contradict the physical law that causality cannot go backwards in time.

It certainly doesn't contradict itself, and I would also assert that it doesn't contradict the physical law that causality cannot go backwards in time. Instead I would say that giving the sane answer to Newcomb's problem requires abanding the assumption that one's decision must be based only on what it affects based on forward in time causal, physical influence.

Comment author: 28 May 2012 07:46:14PM *  0 points [-]

Consider making both boxes transparent to illustrate some related issue.