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.
In the case of both physical growth by eating and mental growth by instruction there is no possible escape from the law of alternating periods of objective and subjective activity. When the child has digested and assimilated a meal there is but one possible thing that can follow—return to his source of supply for another meal. When the student has digested and assimilated the lesson given to him the only possibility of further mental growth lies in his return to the class-room for more material. And so it is with the human soul in its work of evolving its latent powers and possibilities. There is no other road forward but the cyclic one that brings it back to the physical life incarnation after incarnation, but always at a higher point than it previously touched. The very hunger of the child that insures its return to the table for more food is analogous to the desire of the soul for sentient expression that brings it to rebirth.
These alternating periods with the element of constant return are found everywhere in the economy of nature. All her evolutionary expressions are cyclic. But the cyclic movement is not in closed circles. It represents a spiral. The "evolutionary ladder" that the soul climbs is a winding stairway. In its upward progress it makes many rounds but it is always mounting and never returns to the same point. In each cycle, that is made up of the journey from the heaven world through the astral plane, into the physical and then back through the astral plane into the heaven world, it touches each of them at a higher point, or in a higher state of development, than it had previously attained. Each rebirth finds it abler here to gather a larger harvest of experience and each return to the mental plane, or heaven world, finds it abler to digest and assimilate its experiences, and to comprehend more of the realities of the life of its home plane.
This round, or cycle, through the physical, astral and mental regions, is a continuous progressive journey of the soul which began away back at the dawn of mind in man and will continue until he is the perfected mental and moral being. At each incarnation here he gathers experience in proportion to his alertness and to the opportunities his previous lives have made for him. He learns to help others, to be sympathetic, to be tolerant. Such activities will give him pleasure in the astral life and joy and wisdom in the mental region, or heaven world. But he also does some evil things. He makes enemies, he generates hatred and he injures others. This will give him distress in the astral life and no results for soul growth or general progress in the heaven world. If he does an equal amount of good and harm his progress will be slow. If he does much good and little evil his progress will be rapid and his existence happy. If he is a man of great energy, and no very great moral development, and selfishly does much wrong, he will suffer much in the astral life.
It often puzzles the student of elementary theosophy to be told that the soul passes through the purgation of the astral plane and goes on into the heaven world only to return to another incarnation and later to again enter the astral purgatory. Why, it is asked, must one who has thus been purified be again purified? The astral reactions are the results of the blunders made in each incarnation. Each of us in any given incarnation creates by his wrong doing the purgatory that awaits him after death. If he does no wrong there cannot possibly be any reaction. As a matter of occult fact the average good man will find the astral plane life a happy existence and will soon pass on to the blissful heaven world. As for the evil doer the suffering relates only to his evil deeds. Let us say he has committed murder. When the reaction of the evil force he has generated is over and he passes on into the heaven plane it does not mean that he is incapable of future evil. It means that he has probably learned thoroughly the lesson that it is very foolish to take life. But there are many other lessons he has not learned. When he passes into the heaven world he leaves all evil behind him. He is as one who puts his shoes aside to enter a temple. The astral body, like the physical, has perished and it is the freed soul that enters the heaven world. But when he returns through the astral plane to reincarnation he is clothed again in astral matter and this new astral body is exactly representative of his attainments in evolution. In his coming incarnation he will have other physical plane experiences and learn other lessons. The next time probably he will not kill, but perhaps he will cheat and steal or be a drunkard. These errors will react upon him in the astral life that follows. In a coming incarnation he will be wise enough to be temperate and neither cheat nor steal; but perhaps he will be a gossip and work much evil through slander. This in turn will bring its pain. And so in time he will learn to generate no evil force at all but to live in good will and helpfulness toward everybody. Then his progress will be rapid indeed, his life on all planes will be happy and the painful part of human evolution will be over.
The purpose of evolution is no less obvious than the fact of evolution. Evolution is an unfolding process in which the latent becomes the active and the inner life is more and more fully expressed in outer form. The development and improvement in form keeps pace with the necessities of the unfolding life. In the lowest levels of the animal kingdom the form is but a cell. But as the life comes into fuller and fuller expression, limbs for locomotion and, in due course, the organs for hearing, and seeing, and the other mechanism of the developing consciousness, are evolved. In the human kingdom the vehicle of consciousness comes to its highest possible form and then evolution goes on in the perfecting of the physical form. In the process of continually changing the matter of the body it is possible for the brain to be constantly improved and the whole body to grow more and more sensitive and gradually to become a better and truer expression of the evolving life within. In each incarnation the physical body thus improves. The evolution of life and form keep pace. Ultimately perfection of form, as well as perfection of intellect and morality, will be reached and human evolution will be finished.
The purpose of evolution, then, is clear. Man is a god in the making—not actually, but only potentially a god, a being to whom all wisdom, perfect compassion and unlimited power are possible; and by the process of evolution he changes the latent into the active. He is at first only an individualized center of consciousness within the All-Consciousness, a mere fragment of the divine life. His relationship to God is something like that of a seed to its plant, a product of it that has latent within it all the characteristics of the plant and the power to become a plant. It is not a plant and neither is man a god; but when it has sent out a sprout and taken root in the soil it is a plant in the making; and when the human being has begun to evolve his latent spiritual qualities he is a god in the making. The theosophical view is that man is essentially divine.
Critics sometimes ask why, if man is originally divine, it is necessary for him to pass through any evolutionary process. Divinity here indicates merely the essential nature of the human being, not his possession of either knowledge or power or any degree of spiritual perfection. It is as though we should say that the infant son of a great king is royal. The word "royal," like the word "divine," indicates a relationship. The baby royalist is not a king. But he is a king in the making. He has much to learn. He must be educated in statecraft and he must evolve diplomacy. After much experience and development he will, in time, be capable of ruling an empire. At present this helpless infant bears little resemblance to a king. Nevertheless, on the day of his birth he was as much royal as he will ever be. In the same sense the divinity of man represents potential possibilities rather than an obvious fact of the moment. Man is an embryo god and, in time, he shall evolve faculties and powers that his present limited consciousness can not even comprehend. He is not an ephemeral creature of physical origin that lives a brief span to catch a glimpse of immortality and perish, but the deathless son of the living God, and by right divine he walks the upward way of eternal life.