In The Road to Immortality, Frederick Myers says he believes that individual souls are actually the “offspring” of “group-souls.” Today, what Myers called group-souls are called “oversouls”. While some modern thinkers believe that the group-soul concept applies only to the various animal groups and certain types of people, like musical geniuses and gifted scientists, neither Myers nor any other trusted channeled source suggests that membership in a group-soul is in any way limited to specific types of souls with special earthly skills. In fact, it is not unreasonable to assume that ALL souls emanate from group-souls.
According to Myers, each individual new soul comes into existence through one of the numerous oversouls. Each new soul is born into a physical body, but also remains attached to its group-soul during and after its earth life. According to Myers:
“The group-soul is one and yet many. The informing spirit makes these souls one. There are a number of souls all bound together by one spirit, depending for their nourishment on that spirit. There may be contained within that spirit twenty souls, a hundred souls, a thousand souls. The number varies. It is different for each man.
But what the Buddhists would call the karma I had brought with me from a my previous life is, very frequently, not that of my life, but of the life of a soul that preceded me by many years on earth and left for me the pattern which made my life. I, too, wove a pattern for another of my group during my earthly career. We are all of us distinct, though we are influenced by others of our community on the various planes of being.
When I was on earth I belonged to a group-soul, but its branches and the spirit— which might be compared to the roots— were in the invisible. [This] explains many of the difficulties that people will assure you can be removed only by the doctrine of reincarnation. You may think my statement frivolous, but the fact that we do appear on earth to be paying for the sins of another life is, in a certain sense, true. It was our life, and yet not our life. In other words, a soul belonging to the group of which I am a part lived that previous life which built up for me the framework of my earthly life, lived it before I had passed through the gates of birth.” I shall not live again on earth, but a new soul, one who will join our group, will shortly enter into the pattern or karma I have woven for him on earth.
I do not say that this theory, which I offer you, can be laid down as a general rule. But undoubtedly it is true in so far as it is what I have learned and experienced. In this invisible world there is infinite variety of conditions. I can only speak of what I know. I do not claim to be infallible.
Cummins, Geraldine (2012-08-06). The Road to Immortality (p. 29). White Crow Books. Kindle Edition.
Later, Myers makes this succinct statement:
I do not for a moment believe that the individual returns a hundred times or more to the earth. The majority of people only reincarnate two, three or four times. Though, if they have some human purpose or plan to achieve they may return as many as eight or nine times. No arbitrary figure can be named. We are only safe in concluding that, in the human form, they are not doomed to wander over the space of fifty, a hundred and more lives.
Myers humbly suggests that while most individual personalities do not make repeated returns to the earth plane, each of the spirits belonging to a group-soul benefit from the memories and experiences of all the others. Thus, in a sense, each person born into the world has unconscious memories of the numerous past lives of the spiritual siblings who preceded him or her on the earth plane.