The reincarnating process by which the soul evolves is somewhat analogous to the growth of a young physical body. The process consists of alternating periods of objective and subjective activity. How does the body of a child grow? It consumes food, the objective activity. It then digests and assimilates it, the subjective activity. These periods must alternate or there can be no growth, because neither alone is the complete process. The one is the complement of the other. So it is in the evolution of the soul by reincarnation. The experience of life is the food on which the soul grows. The physical plane existence is the objective period in which the food is gathered. At death the man passes into the invisible realms where the subjective process is carried on. He digests and assimilates his experiences and the gist is stored in the causal body and its growth includes an actual increase in size, just as in the case of the child's physical body. The same law governs mental and moral growth as it operates in our daily affairs. A young man is in college. How does his intellect grow? By precisely the same process of alternating periods of objective and subjective activity. In the class room the instructor puts a mathematical problem on the blackboard and explains it. With the outward senses of sight and hearing, aided by pencil and notebook, the student gathers the food for mental growth. This period of objective activity comes to an end and he then retires to the privacy of his room and there the subjective period begins. He deeply thinks over the problem. His material, the food for mental growth, is only a few notes that serve to keep the experience in his mind. At first all that they signify is not obvious, but as he turns the various points over and over in his mind their significance becomes clearer and fuller. It is the subjective process of digestion. Little by little new light dawns in the student's mind. Finally he has complete comprehension of the mathematical principles involved, and the process of assimilation is finished. This subjective period is the complement of the objective period and they must go on alternating or intellectual growth will stop. When the process of digestion and assimilation is finished the student must return to the classroom for further mental food and when he arrives it is by virtue of the fact that he did digest the previous lesson that he is able to take a higher and more difficult one. And precisely so it is with the reincarnating soul. In the interval between incarnations it so assimilates the experiences of the last physical life that it comes to rebirth with added abilities which enable it to take higher and more difficult lessons than it could previously master.