Dr. Caul developed a technique called Internal Group Therapy, IGT , to help multiples improve internal communication and cooperation. John and Helen Watkins , pioneers in developing Ego-state therapy , were his contemporaries. Dr. Caul made many contributions to the field of dissociation. He died on March 14, 1988. My understanding of his book is that unification of parts of Self is impossible because we are not unified in the first place.
Integration is the desirable goal for treatment.
I'll try and summarize what Beahrs meant by his analogy. You need a conductor to conduct the orchestra, violinist to play the viola, and each player plays their instrument. The conductor doesn't play the musical instruments and the players don't conduct the orchestra. Each musician must play their instrument according to the sheet music. No ad lib solos are allowed.