Many-Minds theory as a concept has been given pretty much zero credence. But at the same time there is a requirement for a protagonist that is not the observer.
The observer is the obvious entity to be the significant party in the physics because this is the entity that formulates observations and records them in memory. But this cannot fulfil the other requirements, principally the ability to follow the dynamics of quantum mechanics.
As described by Nobel Laureate Frank Wilczek, the meaning of the quantum theory can hardly be complete without this missing protagonist:
The relevant literature [on the meaning of quantum theory] is famously contentious and obscure. I believe it will remain so until someone constructs, within the formalism of quantum mechanics, an “observer,” that is, a model entity whose states correspond to a recognizable caricature of conscious awareness, and demonstrates that the perceived interaction of this entity with the physical world, following the equations of quantum theory, accords with our experience. That is a formidable project, … only after its completion might one legitimately claim that quantum theory is defined by the equations of quantum theory. (2006, 142)
He puts the word ”observer” in quotes because this is not the observer in the ordinary meanig. The observer is the physical entity that makes the observations. But this entity cannot account for the physics we have discovered. A different ”observer” is required, one that experiences the enactment of the quantum dynamics defined by the equations.
The world hologram fulfils these requirements precisely. As Lockwood describes, the mind is the conscious awareness itself. He calls it the “phenomenal perspective”, “a full state of consciousness”. This is the first part of Wiczec’s requirement. For the second part, there is no question that the perceived interactions of this entity with the environment follow the equations of quantum theory exactly. That is the whole point of Everett’s famous thesis:
It is found that experiences of the observer … are in full accord with predictions … of quantum mechanics (1957, 455)
And as he makes clear, the physical entity of the observer is not in this category. Quantum mechanics does not work for the observer. It is the experiences, the record of observations, that form the protagonist that follows the equations, the world hologram. And Lockwood demonstrates this in the formalism of quantum mechanics
The world hologram is the ”observer” Wilczek describes. This resolves the great paradoxes. The physics works. The quantum theory is indeed defined by the well-established equations of quantum theory.
No Perceiving Subject
There has been very little notice taken about all this because the subjective viewpoint is very carefully eliminated from experiments in physics, and scrupulously excluded from theoretical physics. But as physicist David Mermin states in his article in Nature, this is exactly the reason the physics does not work:
In Nature and the Greeks, Austrian physicist Erwin Schrödinger traced the removal of the subject from science back more than two millennia. Alongside the spectacular success of physical science, this exclusion of personal experience has given rise to some vexing and persistent puzzles and paradoxes. … [These are] resolved by recognizing that the perceiving subject has as important a role to play in understanding the nature of physical science as does the perceived object. (2014)
When Everett’s explanation is taken at face value, the physics makes complete sense as Lockwood shows. With respect to the state of the memory, the world hologram, the dynamics of quantum theory are enacted. Thus Everett’s formulation is the precise resolution of the great paradoxes.
Everett’s protagonist is the ”observer” missing from the physics. And the world of this entity is the superworld, thus explaining the strange nature of the relative world. This is the ontology of the relative world. And this explains how the paradoxical dynamics of the quantum theory operates, as described in subsequent sections here.
It means the body and the mind exist in different types of world. . The body lives in an ordinary world, the mind lives in a superworld. So there are two different types of protagonist of the physics, in the different types of world. No wonder it has been impossible to work out
So there is indeed a fundamental mind-body dualism because body and mind live in the different types of world. The long debate is settled. Mind is information, and body is matter. Body instantiates mind, but mind nonetheless lives in a different type of domain, a superposition of worlds.
The reason quantum theory has been impossible to understand is that this dualism was never imagined. There are two different types of process in quantum mechanics, two different dynamics. They are defined by two different types of equations. Trying to apply these to the ordinary world does not work, as a century of frustration has demonstrated. The resolution is that they are the dynamics of the two types of world. Then the physics works perfectly.
The missing subject, the ”observer’, is the mind, the world hologram. The quantum theory is perfectly defined by the equations of quantum theory. The missing point is the dualism of domains, and protagonists, that operate the two types of equations.