I suspect that most all of our disagreements over the years have stemmed from the differing views we take regarding, what I call, the strange inversion in Mormon reasoning. If you guys (especially Geoff) could take the time respond to that post (here would be better than there, I suspect) I think we could really clarify some of our points of contention.

A coin is tossed. It spins in the air for about a second, and then lands, bounces around on the floor briefly, and settles with heads up. How much force (intelligently applied) would it take over that brief time period to change the result from heads to tails?

In life therer are a lot of chaotic influences combined with sensitivity to initial (or current)conditions that can make a big difference down the line (like the nail, horeshe, horse, rider, battle, war, kingdom scenario). If spirits can make an infinitesimal difference, not noticed by gross instruments, then intelligent application of this power by free spirits can channel the gross matter into fruitful pathways.

I submit, however, that all spirits would logically form one super particle that would follow a branch reflecting the collective will of the ensemble. So no matter where we were, all the spirits would be along for the ride. Like Bohmian QM with spirits as quasi-autonomous identical particles. Pilot the wave, or be piloted, your pick.

The main reason I don’t believe this interpretation is that it would mean that when we look at another person, we could never really tell if this was a branch of that person’s gross physical self that was currently inhabited bv that person’s spiritual self, or not.

So the only purpose of this model is to show the logical consistency of gross material determinism with finer material spiritual free will.

It’s not easy to explain these things in a few sound bytes, so let me know if I need to elaborate.

I’m not saying that I believe in the many worlds interpretation, I’m just saying that it is logically possible, which means that it is logically possible to have a gross material world that is deterministic (since the solution to Schrodinger’s PDE for Psi is uniquely determined by the the initial conditions) but in the form of a branched manifold through which our spirits (not composed of gross material) can pass choosing directions at branch points, i.e. points at which the orthodox interpretation of quantum mechanics would say the wave function Psi “collapsed’ into one of the superimposed eigen states.

All we need is for the “gross material world” i.e. our component of spacetime to be a branched manifold that can be “ridden” by our spirits like tourists in a fund house.

1. The world is real
2. Truth is a function of reality
3. There is only one reality

Since spirits are presumably as real as anything else is, that means our spirits would be cloned in alternative realities as well, and which reality actually was materialized from our perspective would essentially be a statistical accident.

Epistemologically speaking, there (by definition) is no possible way to determine the existence of alternative realities, so the many world interpretation of quantum mechanics is gratuitous in the extreme.

More to the point, it suggests that moral responsibility is worse than an illusion, but rather a matter of dice rolls. That I think is why most people tend to be rather hostile to the idea.

Consistency with settled doctrine and (where possible) with relatively settled physical science (for wont of a better term) is a desirable feature of tentative cosmological theories.

But does this kind of speculation go against D&C 93:25?

D&C 93:24 And truth is knowledge of things as they are, and as they were, and as they are to come;
25 And whatsoever is more or less than this is the spirit of that wicked one who was a liar from the beginning.

It used to worry me that mathematics is not so much about reality as about possibility, so that it could be considered in the category of “less than this.” Is mathematics a curse from “that wicked one who was a lawyer from the beginning?”

I’m sure that many of my students think of it that way.

How do y’all look at it?

No matter how implausible, it is still logically possible, from which we may conclude that there is no logical inconsistency between spiritual free will and gross material determinism.

The many worlds interpretation of quantum mechanics may be completely wrong, but its putative consistency gives us a tool for proving the consistency of spiritual free will with gross material determinism.

The first example of this kind of reasoning was Poincare’s model of non-Euclidean geometry within the interior of a Euclidean disc. In modern language we say that he showed the relative consistency of non-Euclidean geometry with Euclidean geometry.

As you surely know, mathematical logicians have to be content with relative consistency because Godel showed that there can be no purely logical proof of absolute consistency of any set of axioms sufficiently strong to serve as a basis for mathematical analysis.

Since then the greatest examples of this kind of consistency proof are of the form, such and such system is relatively consistent with ZFC (the Zermelo Fraenkel Choice axioms of set theory).

For example, Internal Set Theory (which includes infinitesimals as idealized sets) is relatively consistent with ZFC. IST is Edward Nelson’s elegant version of Abraham Robinson’s Non-Standard Analysis. IST actually includes all of ZFC as a proper subset, yet there are models* of IST within ZFC.

These models are very unwieldy, and have no practical use. Their only purpose is to show logical consistency so that mathematicians can have confidence in their use of infinitesimals and other idealized sets.

Similarly, it is sometimes convenient to use throwaway models in cosmology for logical purposes without getting too attached to them. If classical philosophers had been aware of this, they could have avoided many utterly unnecessary bitter controversies.

*Any one of these models shows that IST is a conservative extension of ZFC, i.e. that anything provable by IST could also be proved by mere ZFC, i.e. the idealized sets are only a convenience.