My memory is incomplete. In Far Journeys, an earlier book, he speaks of reincarnation in a conventional sense. This was before he found out about his I-there.
Ultimate Journey was written after he found out about his I-there. On page 166 the below conversation is recorded:
Robert: "How far back does this [his soul's history] go?"
Robert's I-there: "Before you were born."
Robert: "You had better tell me. I don't remember."
Robert's I-there: "You wouldn't. You didn't exist. We made the decision to become human again. We selected the time and place and organized the DNA mix--elements from the physical and elements from us. We took those parts of us that seemed most appropriate, rolled them up into one, and sent them in. There you are--and we--were!"
Robert: "What exactly did you send in?"
Robert's I-There: "Personalities, memories. What else?"
The above makes me think Robert was a new probe. Whether probes incarnate more than once, I don't remember what Robert wrote.
The above reminds me of the below from Tom Sawyer's NDE:
"Reincarnation is not a linear thing. One of the problems in defining it is that there is no analogy to it. It is outside of time, yet we can't help but think of it in terms of the past and the future, and this incarnation. The whole story is so big and so involved.
Reincarnation is an opportunity to reach a goal. The goal is true self-realization. Self-realization is to know that you are a soul, a part of God, yet also the Whole. Perhaps no one has a very good image at all of his or her soul - the whole self. And they have no idea of what proportion their personality is in relationship to their soul.
As an example, a characteristic of your personality is one percent of all of your personality characteristics put together, and all of your personality characteristics make up your personality, and your personality is only about five percent of your soul, then we are blinding ourselves to 95 percent of the rest of our soul in order to reincarnate.
Reincarnation is an opportunity to evolve through many personalities. The definition of reincarnation is that your personality is who you are in your current lifetime, and that it can be reincarnated as an entirely different personality with the characteristics of the previous personality and previous personalities including even characteristics of another soul altogether. That is, characteristics of your present personality may be the reincarnation of other characteristics of personalities from your previous lifetimes as well as characteristics from personalities from other souls."
http://www.near-death.com/experiences/reincarnation03.html It also reminds me of the below from Ron Krueger's NDE:
"Directly in front of me, but slightly below, stood a group of spirits: less than 100, but more than 50. Each spirit had an identity of sorts, but they were part of each other–a single entity, a single awareness, all part of a single force. In the center of the front row were three oriental women. I realized that all of the spirits comprising the entity were my past lives, and that the oriental women were my most recent lives.
Their faces were clearly humanoid, but from their shoulders down, their forms blurred gradually. Their arms and legs dissolved near their ends. Hovering on the same level, in rows, they seemed loosely joined at the shoulders. Their identities were of both sexes and all nationalities. None were deceased relatives, and I recognized none of them from my recent life.
Each of the spirits had lived once, but the truth and experience and wisdom of each lifetime was integral to the entire group. When each soul returned, their lives were absorbed by all, so there where no distinctions between thoughts and attitudes within the group. Each of them shared completely every experience and every knowledge of every lifetime into a single conscience. Like spices and other ingredients added to a Mulligan Stew, each added to the mix, but the resulting flavor was one. I was them, and they were me. There were all of my past, and they were my present.
They communicated with me as one, not with words, but by a kind of telepathy. Every thought, whether it was one simple emotion or volumes of information, came packaged with instant and complete understanding. No message could suffer misinterpretation, the problems of syntax, or the variance of intelligence."
http://www.nderf.org/NDERF/NDE_Experiences/ron_k's_nde.htm