“If from this believer we pass to the authority of an adept in that mysterious science, the anonymous author of Art-Magic, we find him stating the following:
The reader may inquire wherein consists the difference between a medium and a magician? …The medium is one through whose astral spirit other spirits can manifest, making their presence known by various kinds of phenomena. Whatever these consist in, the medium is only a passive agent in their hands. He can neither command their presence, nor will their absence; can never compel the performance of any special act, nor direct its nature.
The magician, on the contrary, can summon and dismiss spirits at will; can perform many feats of occult power through his own spirit; can compel the presence and assistance of spirits of lower grades of being than himself, and effect transformations in the realm of nature upon animate and inanimate bodies.”
The learned author forgot to point out a marked distinction in mediumship, with which he must have been entirely familiar. Physical phenomena are the result of the manipulation of forces through the physical system of the medium, by the unseen intelligences, of whatever class.
In a word, physical mediumship depends on a peculiar organization of the physical system; spiritual mediumship, which is accompanied by a display of subjective, intellectual phenomena, depends upon a like peculiar organization of the spiritual nature of the medium.
As the potter from one lump of clay fashions a vessel of dishonor, and from another vessel of honor, so, among physical mediums, the plastic astral spirit of one may be prepared for a certain class of objective phenomena, and that of another for a different one.
Once so prepared, it appears difficult to alter the phase of mediumship, as when a bar of steel is forged into a certain shape, it cannot be used for any other than its original purpose without difficulty. As a rule, mediums who have been developed for one class of phenomena rarely change to another, but repeat the same performance ad infinitum.”
H. P. Blavatsky