It has often been asked why, if communication between the physical and astral planes is possible, we do not receive information that might lead to valuable discoveries and inventions. The very fact that death does not confer wisdom explains it in part. But an even more important fact is that communication is easy with the lower levels and correspondingly difficult as the higher levels are reached. All who have had much experience with seances are familiar with the fact that "guides" or "controls," that is, the persons in the invisible realms who direct the seance and frequently speak through the medium, are very often Indians or others at a low level of evolution. The majority of the inhabitants of the astral levels with which communication is easy are not the type capable of furnishing ideas of any great value. It is on the higher levels that the man of intellectual power passes most of his astral life. The scientist or the inventor who has given so much thought to his work that he has been in some degree successful here is not likely to have much consciousness on lower levels. It is the highest of the seven subdivisions of the astral world that is the habitat of the person who has followed intellectual pursuits, during physical life, and with that level it is practically impossible for the ordinary medium to communicate. One of the objections to indiscriminate communication with the astral plane lies in the very fact that the lowest class of entities are most accessible. That not only accounts for the commonplace messages in such abundance, but it is frequently a source of actual danger, especially where people form "circles" for the purpose of rendering themselves more sensitive to psychic influences. In such cases it is common to accept every message as absolute truth. There is no doubt that as a rule the astral people in charge of such a gathering are earnest and honest. But they are neither all-wise nor all-powerful, and it sometimes comes about that some of the sitters are partially or wholly obsessed by astral entities, and that may prove to be an exceedingly serious matter. Some people have thus lost their sanity and others their lives. It is, of course, only the gross type of astral person who has a desire to seize upon the physical body of another. The purpose is to gratify desires that have outlived the physical body. The dead drunkard is perhaps the commonest example of the obsessing entity, and if the obsession is only partial it may lead to nothing worse than strong and perhaps irresistible impulses toward alcoholic stimulation. Obsession may, of course, occur without the psychic door being opened deliberately. But no obsession is possible, in any case, unless there is something within the victim responsive to the moral defect of the obsessing entity.