Here's something I have read I thought would contribute to this topic.
' One of the major lessons to be learnt upon the Path of Discipleship is to learn to distinguish that which is real from what is illusion.
What then is to be seen and heard by the medium when in trance, or when giving an exhibition of clairvoyance or clairaudience? Several possibilities, which I might list as follows:
A revelation of the ‘wish life’ of the person or group to whom the medium is addressing himself. This wish life takes form in proportion to the power of the unexpressed wish, or the mental ability of the persons concerned.
Recognition by the medium of the thought-forms, or thought-form to be found in the aura of the person in the audience or circle. These thought-forms have been built over a space of time, and are usually of someone deeply loved, or as deeply disliked. They are often so real in appearance, that the person can recognize them when described by the described medium, and the medium can at the same time by a process of telepathy (via the solar plexus centre) become aware of the things which the sitter wishes to hear, which will be in line with the usual mannerisms and methods of speech and thought of the departed or living friend. This accounts for the mediocre calibre of the usual utterance and statement made at a séance. The average person who frequents at a séance, is not usually of the highest grade of intelligence, unless he is simply there as an investigator.
A few rare cases when a soul on the path of return to incarnation, or immediately after death, is impelled (for good and sufficient purposes) to make a contact with a friend or relative via a medium. Such cases are known, and usually presuppose more than average intelligence on the part of the sitter, the communicator, and the medium. They constitute, however, the exceptional occurrence.
The revelation to the clairvoyant and clairaudience worker of much of the phenomena of the astral plane, which parallels that of the physical plane, and which is conditioned by the quality and calibre of the circle of people who constitute the audience. This the medium interprets to them, and it usually evokes recognition.
I am here casting no doubt on the sincerity of the performance, nor on those mediums who are born with these clairvoyant and clairaudience faculties. I am only pointing out that the phenomena which they are contacting, in astral nature, and that anyone looking at a circle, from the standpoint of the higher psychic powers, would note around each sitter, a group of astral forms (self created) of those who have departed physical life through death, of those who are constantly in his thoughts though still alive, and also a kaleidoscopic and changing process of appearing and disappearing forms (some quite nebulous, and some quite substantial, according to the power of thought) which concern the wish life of the sitter, which are concerned with his home affairs, his business, or are built up around his health. The sensitive tunes in on these, connects them with the attendant thought-forms, and hence the production of the usual performance found in the séance room, or with the average audience. The medium is truly and accurately relating just what they see and hear, and therefore is sincere and truthful, but because he receives no real training in the art of interpretation, and in the technique of distinguishing the illusory from the real, he is perforce, unable to do more than the phenomena seen, and the words heard.
When, however, the mystic opens up these same powers, as is sometimes the case, the phenomena seen and the words which are heard, can be of a very high order. Nevertheless they are still astral, for they concern happenings and phenomena, found upon the higher levels of the astral plane. He comes into contact with the spiritual or religious wish life of the race, and according to the basic trend of his individual aspiration at the moment, so will be his contacts. If he is an earnest and devoted Christian, he will see one of the beautiful and vital thought-forms of Christ there to be found, and in the wonder of the revelation, his love and his imagination, and all that is best in him, will be adorned in adoration and mystery. Heed some of the inspired writings and illumined vision of the mystic. If he is a Hindu, there may come to him vision of the Lord of Love, Shri Krishna, or, if Buddhist, he may see the Lord of Light, the Buddha, in all his radiance. If he is an occult student, or a theosophist, or Rosicrucian, he may see a vision of one of the Masters or of the entire Hierarchy of adepts; he may hear words spoken and thus feels assured, past all controversy, that the Great Ones have chosen him for special privilege, and for unique service. And yet, his consciousness has never moved from off the astral plane and his contacts have only been a wonderful and inspiring expression of the phenomena of that plane, released to his inner sight and hearing through aspiration.
All this is brought about through the over-activity of the solar plexus centre, stimulated by the energy pouring in from the heights he has attained in aspirational meditation. …. (And so it continues). '