Perennial Idealism: A Mystical Solution to the Mind-Body Problem

Beyond Physicalism, released by Esalen, has a variety of Idealist possibilities that seek to reconcile parapsychogical data with the rest of the sciences. [NDEs, mediumship, reincarnation, etc.]

Interactive Dualism would leave open the question of how the two substances interact. It would also leave open the question of how we got everything in consciousness and everything we perceive as the physical world.

So even [if] we had the souls of the dead just hanging out with the living, people would still wonder how the entirety of Reality fits together. This is why people like the Neo-Platonists and Vedic sages who at the least claimed to have experienced all sorts of parapsychological phenomenon continued to ponder how to reconcile the realm of souls and the realm of the body.

This isn't to say Perennial Idealism is correct. Like most metaphysics it is better than the Something from Nothing nonsense of the Physicalist Faith, but then it runs into problems of its own. Here, namely, how does Pure Awareness, a consciousness without perspective, create all the subjects who have their own private experiences? The idea is that this Awareness is actually a Void of Infinite Potential that gets actualized, but while this works for nonconscious stuff this seems less explanatory for the emergence of experiencing subjects.

One possibility is that all Subjects have no need to arise because they were always Here, that each perspective existing now has always existed. This would suggest souls are not just immortal but arguably Eternal.

There are problems with all theories and philosophies of the nature of the mind-body complex. Including Perennial Idealism as you mention. So it's no surprise that there is the famous Interaction Problem with Dualism. There are also always ingenious philosophical rejoinders to all these problems. That's why philosophical debates are endless. My view is that the empirical evidence is paramount and the theory that explains this data in the least complicated way is most likely correct. This is of course the Occam's Razor principle. It's not an invariable law, just a principle that from experience points to the most likely explanation. It seems to me Interactive Dualism is the most direct and simple explanation of the data.     

As to Idealism. Objective Idealism is the only form of Idealism that seems to me to be reasonably compatible with the paranormal data, without a lot of special rationalizations. This posits "....the existence of a separate objective consciousness which exists before and, in some sense, independently of human consciousness, thereby bringing about the existence of objects independently of human minds" (Wiki). This would need perhaps to be combined with the proviso that this is reality as experienced, but at the ultimate underlying level of existence an all-pervading consciousness is the ground or true nature of all of reality including conscious beings This all-pervading consciousness would have various names including God or the mind of God.