Mediumship

Mediumship in Spiritism and Spiritualism is the ability of certain people —known as mediums— to mediate communication between dead people and living human beings.

H. P. Blavatsky wrote:

Mediumship. A word now accepted to indicate that abnormal psycho-physiological state which leads a person to take the fancies of his imagination, his hallucinations, real or artificial, for realities. No entirely healthy person on the physiological and psychic planes can ever be a medium. That which mediums see, hear, and sense, is "real" but untrue; it is either gathered from the astral plane, so deceptive in its vibrations and suggestions, or from pure hallucinations, which have no actual existence, but for him who perceives them. "Mediumship" is a kind of vulgarised mediatorship in which one afflicted with this faculty is supposed to become an agent of communication between a living man and a departed "Spirit." There exist regular methods of training for the development of this undesirable acquirement. KT, Glossary

Traditionally, Theosophists have been opposed to this practice saying that "on the whole, mediumship is most dangerous"CW12, 373. As H. P. Blavatsky wrote:

The medium’s moral state determines the kind of spirits that come; and the spirits that come reciprocally influence the medium, intellectually, physically, and morally. The perfection of his mediumship is in ratio to his passivity, and the danger he incurs is in equal degree. When he is fully “developed” — perfectly passive — his own astral spirit may be benumbed, and even crowded out of his body, which is then occupied by an elemental, or, what is worse, by a human fiend of the eighth sphere, who proceeds to use it as his own. But too often the cause of the most celebrated crime is to be sought in such possessions. IU1, 490

6th. Mediumship is the opposite of adeptship; the medium is the passive instrument of foreign influences, the adept actively controls himself and all inferior potencies. IU2, 588

Mediumship is abnormal. ML18