Annie Besant points out here that the doctrine of Reincarnation does not belong only to the East but was part of primitive Christianity and other religions. It is essential for arriving at a rational explanation of life and of human progress and character. From the moral standpoint also, it is a necessity, if faith in Divine Justice ans Divine Love is to be sustained while facing pain and difficulties. It is reasonable to accept Reincarnation,  at least as a postulate, if human life is destined to reach Perfection.