Friday, November 12, 2021

Ethics and multiverse interpretations of quantum mechanics

Somehow it hasn’t occurred to me until yesterday that quantum multiverse theories (without the traveling minds tweak) undercut half of ethics, just as Lewis’s extreme modal realism does.

For whatever we do, total reality is the same, and hence no suffering is relieved, no joy is added, etc. The part of ethics where consequences matter is all destroyed. There is no point to preventing any evil, since doing so just shifts which branch of the multiverse one inhabits.

At most what is left of ethics is agent-centered stuff, like deontology. But that’s only about half of ethics.

Moreover, even the agent-centered stuff may be seriously damaged, depending on how one interprets personal identity in the quantum multiverse.

Consider three theories.

On the first, I go to all the outgoing branches, with a split consciousness. On this view, no matter what, there will be branches where I act well and branches where I act badly. So much or all of the agent-centered parts of ethics will be destroyed.

On the second, whenever branching happens, the persons in the branches are new persons. If so, then there are no agent-centered outcomes—if I am deliberating between insulting or comforting a suffering person, no matter what, I will do neither, but instead a descendant of me will insult and another descendant will comfort. Again, it’s hard to fit this with the agent-centered parts of ethics.

The third is the infinitely many minds theory on which there are infinitely many minds inhabiting my body, and whenever a branching happens, infinitely many move into each branch. In particular, I will move into one particular branch. On this theory, if somehow I can control which branch I go down (which is not clear), there is room for agent-centered outcomes. But this is not the most prominent of the multiverse theories.


swaggerswaggmann said...

So you watched Stargate atlantis ?

As for you you did the right thing. Only the parallel others have not.

Can't you be a good man because Hitler isn't ? Do you really need a skydaddy to answer this question ?

Alexander R Pruss said...

Suppose two strangers are drowning. You can save A and I can save B. Suppose, too, that if you don't save A, then I will save B, and if I don't save B, you will save A. Is there any point to your saving A? Either way, one person will be saved. Why grab the glory for yourself?

scott said...

Not sure this helps with the multiverse interpretations of quantum mechanics. But I don't think this is a problem for Lewis' modal realism. I think if you're a two boxer, Lewis' view can handle this problem.

Alexander R Pruss said...

Thanks for the paper link. It's very clever, but I am not convinced.

For the analogy with Newcomb cases to work, the Newcomb cases have to be the strict kind, where the predictor has no possibility of making a mistake. The only way for such cases to be compatible with free will (say I the incompatibilist) is if there is something like backwards causation (or at least backwards quasicausation, mediated by the knowledge of God). But in cases where there is backwards causation, one-boxing is the right strategy.

scott said...

Thanks for this criticism and for looking at the paper. I was thinking of modal realism as part of a broader systematic philosophy. I thought I could take for granted two boxing because that was Lewis' view. And I think I can take for granted compatibilism because that is his view as well. If the strategy doesn't work because some other aspect of Lewis' view doesn't work, then I'll still be satisfied. We started with two possible worries for Lewis. One worry is that compatibilism is false. Another worry is that modal realism leads to moral indifference. If the response doesn't work because compatibilism is false, then I'll still have done my job. We started with two problems. Now there is just the one. Lewis view doesn't work because it assumes compatibilism. Or so it seems to me.