26. NOTE - A common comparison would make this difference more easily understandable. The scholar cannot reach superior studies in science if he has not passed through the series of classes which lead to that level. These classes, whatever may be the work demanded, are the means by which the student will reach his objective and are not a punishment inflicted upon him. If he is diligent he can shorten the path and consequently will encounter less thorns. However, this does not happen to the one who is negligent and lazy, which will oblige him to repeat certain lessons. It is not the work of the class which is the punishment, but the necessity to recommence the same work over again.
This is what happens to mankind on Earth. For the primitive Spirit, who is only at the beginning of his spiritual life, incarnation is the means by which he can develop his intelligence. Nevertheless, it is a punishment for an enlightened man, in whom a moral sense has been greatly developed, to be obliged to live over again the various phases of a corporeal life full of anguishes, when he could have arrived at the end of his need to stay in inferior and unhappy worlds. On the other hand, if he works actively towards his moral progress, he not only shortens the period of his material incarnations, but also may jump over the intermediate steps which separate him from the superior worlds.
Is it possible for Spirits to incarnate only Once in any one world and then fulfill their other existences in different worlds? This would only be possible if every person were at exactly the same point in both intellectual and moral development. The differences between them, from the savage to civilised man, show the many degrees which must be ascended. Besides, an incarnation must have a useful purpose. But what of the short-lived incarnations of children who die at a tender age? Have they suffered to no purpose, for themselves or for others? God, Whose laws are wise, does nothing that is useless. Through reincarnating on the same globe, and by being once again in contact with each other, He wishes these same Spirits to have the desire to repair reciprocated offences. With the help of their past relationships, He wishes to establish family ties on a spiritual basis, founded on the principles of the natural laws of solidarity, fraternity and equality.