Now, since we are thinking in terms of archeological layers, we would continue to express ourselves along those lines. So. Directly beneath personal subconscious you will find upon examination either through hypnosis or applied association, a layer dealing with the period before this life, and after the life before this one.
Since this period was to some degree at least free of camouflage, from it communication can be received dealing with the entity's knowledge of itself, and of uncamouflaged reality. From this undifferentiated gap of experience between camouflage existences, valuable information may be received dealing with the reality which exists behind, and independent of, matter.
From this focus position communication may be set up between personality essences no longer in the physical field, and those still in it, provided that those still in it are able to remove focus from the ego to this particular level. It is from this focus point then that communication between what is termed the living and the dead may take place. The necessary focus point may be achieved through trance, hypnosis or self-hypnosis, or through certain other disciplines.
Basically, Seth is saying that if you hypnotize someone, you can extract information about that person's past lives and "between life" state. Nowadays, you can't throw a rock in a bookstore without hitting a book explicating "life after life" or "life before life." However, these concepts were unknown in 1964, when the above was dictated. As far as I know, the first popular, mainstream book that purported to examine conscious existence "between lives" was Helen Wambach's "Life Before Life" (which I bought in 1981). The method by which she compiled her data was a sort of group hypnosis. No one, apparently, had thought to use hypnosis to obtain this data--and publish the results in the mainstream--until then. Michael Newton, of course, perfected the process and published his classic studies beginning in the 1990s. The point is, it's extremely unlikely that Jane Roberts could have articulated such a process in 1964. Not only do I believe that this is a validation of the Seth material, I also think it validates Dr. Newton's work.