The aim of reincarnation was established by Allan Kardec, in reproducing the following thought of the Spirits:

[...] If there were no mountains, man would not understand that one can go up and down; if there were no rocks, he would not understand that there are hard bodies. The Spirit needs to gain experience; it is necessary, therefore, to know good and evil. That is why it joins the body. [i]

The Spirit, according to the text, joins the body, through the dynamics of reincarnation, to understand, to know and to gain experiences. Experience consists of the act or effect of experiencing, arising from that practice a certain experimentation, which translates into skill. The authors of the text evoke much more states of feeling than states of intellect. No one can explain to the other person, who has never known a certain feeling, what the quality or value of it consists of. We must have musical ears to judge the value of a symphony; we must fall in love to understand the state of mind of someone who is in love. If we lack our heart or our ears, we cannot understand the musician or the lover correctly.

On the other hand, when they state that it is necessary for the Spirit to acquire experience through the knowledge of good and evil, they may be referring to experiences in distinct environmental contexts (some predominate in good, others in evil), but, perhaps as a priority, they are referring to the learning that the Spirit is building for himself through his successes and mistakes. Not to theoretical knowledge that only provides a description exempt of experience; but to the living and real experimentation of the proposed reality. Reading about certain pain in a medical compendium does not give the patient the experience of truly knowing the essence of pain. It is the experience that gives total knowledge, because it unites theory to practice, closing the circle of knowledge. Thus they may be referring less to the intellectual knowledge of good and evil (knowledge that certain things are wrong), and more to the experimental knowledge of good and evil (knowledge of the sense of error and rightness). Certain experiences that give pleasure to the Spirit are repeated by it in the quest to perfect a formula that gives it gratification. Others, whose end result does not satisfy it, are avoided. This is how, little by little, it builds its methodology in the attempt to suffer less.

Examining this issue, the Cuban anthropologist Fernando Ortiz reminds us that the Spiritists’ evolutionism is as fatal as that of biologists. If the naturalists say natura non facit saltum (Nature does not jump), the Spiritists can say, similarly, spiritus non facit saltum (Spirits do not jump); the Spirit will rise slowly or quickly, according to its effort; however, it will be step by step, until it reaches the superiority of the "angels".

Some points are put in an initial reflection: could the Spirit live the experiences of growth exclusively in the spiritual dimension? How do experiences differ in the two dimensions? Let us examine these questions.

The contemporary mediumistic literature, especially the vast work of the Spirit Andre Luiz, dictated to Chico Xavier, presents the notion of the spiritual colonies, real cities of the Beyond, where hospitals, schools, residences, transportation vehicles, music and art gardens are described for entertainment, and so on. This metaphysical reality is described alongside an intense social and community life, which is identified in many details with the life experienced in the physical dimension. Is it natural, then, to inquire whether, in the face of such a condition, Spirits could not expand their potentialities - intellectual-moral progress - exclusively in that community? What is the sense of body, if all the conditions found here on Earth are likewise found there in the spiritual colonies?

Although the spiritual dimension in many ways identifies with living conditions on Earth, there are differences between them. These differences are what give meaning to reincarnation. The physical dimension differs from the spiritual dimension in the following aspects:

1- The insertion in a life cycle that is specific to the biology of reincarnation: to be born, to grow, to fall in love, to reproduce, to raise children, to grow old, to identify oneself with a body with peculiar genetic characteristics and to experience diseases that are unique to the body. Each of these processes offers the reincarnated different possibilities of internalizing signals that meet their own maturation, developing their abilities. The experience of pregnancy and motherhood, for example, is unique in the sense of experiencing certain emotions that only belong to this condition. Women who have lived these experiences can tell what this meant to them. In the same way, the experience of aging which sends messages to the inner of the being. If well understood and experienced, these messages can be transformed into elements of growth. Many people say, at the end of life: "How much did I learn from old age! If I had at the age of thirty the knowledge that I have today, I would have made fewer mistakes!" Such a cycle of life, as we know it, does not seem to exist in the spiritual dimension.

2- The struggle for survival: insertion into the physical dimension places the Spirit in an environment in which activity and labor are practically obligatory; otherwise, hunger, disease and death take place. This does not happen in the spiritual dimension (because, since they are already dead, they cannot die again). Work is the engine of progress and unceasing activity is the lever in the development of the intelligence. Solving problems related to the act of living itself develops the intelligence and expands the mental possibilities of the Spirit. Historically, we are survivors of great tragedies, which have required of us an immense effort. We owe this effort to our survival. About 65 million years ago, the fall of a huge meteorite in the Gulf of Mexico decimated 90 percent of everything alive on Earth. Our ancestors survived because they were able to overcome adversity.

Much later, as Africa became gradually drier and the rainforests disappeared, our closest cousins, the primitive apes, had to choose between two paths: to remain comfortably in the remaining forests or to "descend from the trees" in search of a new habitat. The ancestors of chimpanzees, gorillas, gibbons and orangutans were left behind, giving birth to the current primates. The ancestors of other apes ventured into the forest and launched into competition with other terrestrial animals, already adapted to the ground. It was a dangerous undertaking, but one that was successful: these apes gave birth to man. So, because we have overcome adversity and courageously admit challenges, we become what we are.

3- The period of childhood, making the Spirit more accessible to the characterization of the Spirit, through education and the good examples of parents, teachers, and the salutary intervention of religions. These interventions, as well as positive, can aid in the moral transformation of individuality. How do we transform, in good men, so many Spirits crystallized into evil, if not by making them go through multiple periods of childhood, leading them to a healthy coexistence with loving but disciplining parents, who will be sowing in their hearts the seeds of goodness, justice and consideration for the like? One reads in Kardec: It is not rare for a bad Spirit to be given good parents in the hope that their advice will lead him on a better path, and often God will grant him what he desires. There is no childhood, as we know it, in the spiritual world.

4 - The forgetfulness of the past, which allows the individuality to live with its enemies, without remembering their mutual follies. Such memories could revive animosities, creating embarrassment to the harmonization of relationships. The memory of our previous personalities would have very serious drawbacks; it could, in certain cases, shame us greatly; in others, it could stimulate our pride and thereby to affect our free will. According to Kardec, God has given us, to improve ourselves, exactly what is necessary and sufficient: the voice of conscience and our instinctive tendencies, depriving us of what could harm us.

If we remembered what we did before, we would also remember what others did, and this knowledge could have the most disastrous effects on our social relations. [ii]

Kardec, examining the return of the Spirit to the corporeal world, comments that when the child breathes, the Spirit begins to recover the faculties that develop while the organs that form the body - and will later be used to manifest - are formed and consolidated too. But when the Spirit regains consciousness of itself, it loses its memory of its past, without losing the faculties, qualities and aptitudes previously acquired, which were temporarily in a state of latency and that, returning to activity , will help it to do more and better than before. The Spirit is born again in the same level it was due to its previous work; its rebirth is a new starting point, a new step to climb. Still the goodness of the Creator manifests itself, for, added to the bitterness of a new life, the memory, often distressing and humiliating of the past, could disturb and create embarrassment. It brings what it has learned in the form of tendencies and inclinations, for it is useful. Thus, a new man is born, even though it can be very old as a Spirit. It adopts new processes, aided by its previous acquisitions. When it returns to the spiritual life, its past unfolds before its eyes and it judges how it employed time, whether good or bad. There is, therefore, no solution of continuity in the spiritual life. Each Spirit is always the same self, before, during and after the incarnation, this being only a phase of its existence. [iii]

5- The coexistence with people of different evolutionary levels. In the spiritual dimension, the law of attunement is absolute. The similar seek in the immensity of space, constituting related groups. In the physical dimension, this is not the case - they all live in a "can of worms": the responsible person next to the irresponsible, the fair next to the unjust, the wise next to the dumb, the gentle next to the coarse, and so on. Living together in diversity stimulates progress. Those, who are in a lower evolutionary condition, have in their superiors the example and the stimulus for self-improvement. Those in a superior position find in the coexistence with those, who are in an inferior position, the opportunities to exercise tolerance, patience and perseverance. Therefore, the differences that exist between us should not only be respected, they are the wealth of humanity, because they form the broth of culture that serves as the basis for a philosophy of dialogue. If all were absolutely equal we would not find the triggers of personal development. Kardec admits this by pointing out that the differences between the Spirits are necessary to their personalities.[iv]

The various conditions implicit in the concept of corporeity allow the reincarnation to live different experiences, which are always experiences of growth. In each experience, it internalizes achievements, learning from mistakes, expanding the possibilities of the mind, developing emotions, conquering higher feelings, developing the powers of the Spirit, dormant in their individuality.

There are many experiences: the experience of scarcity and the experience of abundance, professional challenge and perseverance, chronic illness and the limitation of one of the physical senses. Also the experience of beauty, ugliness, unemployment, financial disaster, unfavorable genetics of social vices and chemical addiction, the pernicious environment, the bad example of the parents, the good example of the parents, the healthy environment, the solitude and of the affective frustration sensitizing us to take better care of the springs that feed our hearts, and so on.[v]

To live the experience and give meaning to it to learn: learn to be, to know, to do and to live. To learn to yield, to love without conditions, to serve without waiting in return, to wait patiently, to listen attentively.

Look for experiences that teach us to value other pleasures! From the biological point of view what matters is the genetic success, i.e., the survival and reproduction of the being. The law of natural selection takes care that they survive and reproduce the fittest beings. The human species has developed, through evolution, mechanisms in your brain that contribute to this biological fitness or adaptation, that is, to survive and reproduce. One such mechanism was to equip the brain with a toolbox of pleasure, leading Homo sapiens to consider as pleasurable anything that could contribute to its genetic success. The main instruments of pleasure in the brain, according to evolutionary biologists, are related to food, sexuality, security, parenthood, friendship, status and knowledge. We need now to discover pleasures other than those biologically defined by evolution: the pleasure of simple things such as friendly conversation, music and reading; the pleasure to help, to study, to discover, the pleasure of feeling the spiritual growth.

For no one learns from the experience of the other. When a journalist asked Dr. Elizabeth Klüber-Ross if she believed in Spirits, she replied emphatically:

 "No, my daughter, I do not believe! I know Spirits exist".

For her, the existence of a spiritual world was no longer a matter of faith, of belief. She herself had lived her psychic experiences, for she had spoken to the terminally ill who appeared to her after death, telling her of the immortality of the soul. She did not need the device of faith, because she no longer depended on the experience of another person. When we live the experience, it is no longer a question of faith, but of conviction.

An American comedian jokingly said that the day he went to High School, his mother went to school and told the teacher, "When my son behaves badly, please hit the child next to him and so he will learn by example." What makes this a joke is the absurd of the idea. The experiences of others can inform us about a given situation, clarify us about facts and consequences, but can never be counted as elements of personal improvement: progress is particular, proper, nontransferable, because it occurs in the inner of the creature. It is given from the inside out. No one will deny the value of study and enlightenment. But their value lies in facilitating our realization, clarifying one or the other, but they do not represent true spiritual development, which takes place in the concreteness of real life.

Learning requires that the action of doing takes place, and often this action is repeated several times. Let's see the following example: we want to bake a chocolate cake as taught in a particular TV show. What are the steps to follow? We sit in front of the TV with a notebook. We attentively watch every step, carefully seeing how it is done. We memorize the recipe. We are able to reproduce the recipe. However, can we say that we can make the cake? Obviously not! To learn how to bake a cake, we have to work the dough, i.e., we need to put into practice what we learnt in theory. In the first attempt, perhaps, the dough does not bake properly; in the second, it is too fluffy; and in the third, it will stick to the cake pan. Only after several attempts, the cake is good. Then we can say: we learnt how to bake a chocolate cake!

Evolving is, in a certain way, like learning to ride a bicycle. If you want to do it, do you enroll in theoretical course or do you buy a manual "How to ride a bicycle"? No! The apprentice climbs on the bike and tries to ride it. He will stumble a few times, until his brain, "taming" the balance-related circuits, automates the process and learns to ride the bike without falling. As a young Spirit, in primitive incarnations, the bicycle is offered to us with two wheels. The tutelage of Higher Spirituality is greater, as it is with children, and the evolution is slower. Later, a little more matured, one of the casters is removed (as if the guardian angels said "try it yourself!"). Later, finally, identified with a conscious evolution, more mature in the face of the possibility of doing for ourselves, the second wheel is also withdrawn and we become responsible for our choices.