"Normally, disincarnation (physical death) should occur in old age. The human body is like a flower or a fruit: It is born, grows, blooms, and withers. When it withers, it ceases to be useful to the spirit. The one natural, spontaneous, wise solution therefore would be disincarnation. Only in exceptional instances may disincarnation take place, without loss to the spirit, before man has completed the four stages of earthly existence. For instance, when a spirit belongs to a higher class than the 17th and incarnates on a special mission to awaken mankind or to contribute to moral changes designed to hasten the rhythm of evolution on this planet. "