Question: When a new soul joins a soul already in a human body, what does the previous soul think?
Sri Chinmoy: One body cannot have two souls. But if the old soul is not functioning well through the physical, the vital, the mind, then, if it is the Will of the Supreme, the old soul can be replaced by a more dynamic and progressive soul.
Sri Chinmoy, The soul and the process of reincarnation, Agni Press, 1977