# jimmy comments on Decision theory: Why Pearl helps reduce “could” and “would”, but still leaves us with at least three alternatives - Less Wrong

29 06 September 2009 06:10AM

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Comment author: 07 September 2009 06:25:45PM *  3 points [-]

If you flip a quantum coin you may end up with a dead cat and an alive cat in different Everett branches, but that is not what we're talking about.

What we're talking about is that if you're decision algorithm outputs a different answer, it's a different algorithm regardless of where this algorithm is implemented. Same as if you're getting a result of 5, you're not calculating 1+1 anymore- you're doing something else. You may be ignorant of the output of "1+1", but it's not mathematically possible for it to be anything other than 2.

Comment author: 07 September 2009 06:54:05PM -2 points [-]

I can see what you are talking about - but it isn't what was originally being discussed. To recap, that was whether different actions are logically possible.

That seems like the same question to whether it is logically possible to have different worlds arising from the same initial conditions just before the decision was made - and according to the MWI, that is true: worlds branch.

The actions are the result of different calculations, sure - but the point is that before the decision was made, the world was in one state, and after it was made, it is divided into multiple worlds, with different decision outcomes in different worlds.

I classify that as meaning that multiple actions are possibilities, from a given starting state. The idea that only one path into the future is possible at any instant in time is incorrect. That is what quantum theory teaches - and it isn't critical which interpretation you pick.