Thetans are *not* the equivalent of human souls at all.
They are a non-human, but not superhuman, parasitic intelligence that can infest the brains of human beings.
Wheras in an uninfected human, consciousness is a neurological function of the brain, for the Thetan parasites, the brain is just a niche in the local ecology. Thetans don't generally have full control over their host "meat bodies". They are often simply passive, like remoras on a shark. But sometimes they do manage to take over their hosts.
L Ron Hubbard was a Thetan host. As a human being, he was so weak that eventually the Thetan controlled him completely. And it resolved to help other Thetans take fuller control of their hosts. So it created Scientology. The personality test, the volcanos, all of the trappings of Scientology recruiting are carfully concieved to find people with Thetans in their brains.
Scientology does what it says it does - it puts one's Thetan fully in control. Only it's not what you think it is.
What Hubbard called "the reactive mind" is in fact normal, natural, human consciousness, and auditing and TR's help the Thetan to become "clear" of it. That's why becoming Clear is an important first step for an awakening Thetan, and a priority of Scientology processing.
Hubbard dreamed of allowing Thetans to be not merely in control of their host "meat bodies", but to be independent of them, to transcend parasitism, to become an independently Operating Thetan. But he never quite figured out how to do it.
In fact he was nowhere close. As I said, Thetans are not superhuman intelligences, just...alien.
The same inner weakness that made the Hubbard meat body such a useful tool for the L. Ron Hubbard Thetan made it very attractive to other Thetans. Like the tropisms of flatworms, Thetans without meat bodies were drawn to Hubbard, and began nesting in his ganglia and lymph nodes:
Body Thetans. The L. Ron Hubbard Thetan fought hard to retain control, and in the process wore out the brain and body of the human that had been Hubbard, and that meat body died, screaming about the invisible animal struggle of Thetans in his body.
So you see, Sceintology not only believes in alien invasions, Scientology *is* an alien invasion. Scientologists are in fact parasitized human beings, human beings who may or may not live long enough for the Thetan to depart or go dormant.
I may be the first human being on Earth to cross this "wall of scorn". Past lives...space opera...robotic behavior...so many things make sense now.
I provide here only that which is needfull...
