This section is only intended as an entertaining interlude.

There are 3 famous science fiction stories about BT-like entities who control us and feed on our emotions.  These stories all have the idea that the entities themselves block our ability to see them (which has some truth to it, I didn't see active BTs as sparks until I had done a good bit of Nots, and these sparks are visible to the naked eye and you will see one entering or leaving somebody occasionally).  They also include the idea that if you find out about them while you're still under their control, they will make you kill yourself (which does not seem to be the case).  Furthermore, they include the idea that if somebody were to get rid of these entities, other people who still had them would be influenced to hate the person who had gotten rid of them.

Except for the bit about them blocking perception, all these ideas seem to be false.  But they make for very interesting reading.

The ideas trace back to Charles Fort, who came to the conclusion that we are cattle, owned and milked (for emotion or energy) by hidden beings.

The first and most famous of these stories is "Sinister Barrier" by Eric Frank Russell.  If I remember correctly, it was written in the late 1930s during Russell's Fortean period (he also did a short story about continents in the sky, and a powerful but outdated novel about Earth the prison planet called "Dreadful Sanctuary").  Russell calls them Vitrons and has them hovering over the person's head.  The book opens with people who discover this being forced to commit suicide.

This novel was well known to Ron and may partially explain why he put such fantastic cautions on dealing with these things. Its amusing to note that at the end of the original version of "Dianetics the Evolution of a Science" which appeared in the May 1950 Astounding Science Fiction, there were an extra few paragraphs where he mentions Russell's book.  It was something to the effect that Russell was right in saying that there was a sinister barrier, but the barrier was not from some outside agency, it was in men's own minds.

The next of the famous ones (there are certainly other stories in this vein) is Colin Wilson's "The Mind Parasites".  Again the story opens with suicides, and the hero manages to overcome the impulse when he realizes it is coming from an outside source. Eventually a team of people who managed to free themselves from this influence discover that these entities were blocking OT abilities and begin mastering telekinesis etc.  The same author is also famous for his writings in the field of metaphysics. The science fiction movie "Lifeforce" was based on one of his stories.

The third one is "Noplegarth" by Jack Vance.  His entities are called "Noples" and anyone who doesn't have a Nople can see them riding on other people's shoulders.  The interesting twist in his story is that when people finally become free of their Noples, they can now be grabbed and taken over telepathically by an even worse being who lives on a far planet.

All of these are well written and quite entertaining.  And reading stories is a good way to try out ideas and consider them in the abstract without getting your own fears and personal considerations mixed up into it.