It is obvious that this theory can only account for a very small proportion of the facts observed. I am willing to admit that some so-called mediums of whom the public have heard much are arrant impostors who have taken advantage of the public demand for spiritualistic excitement to fill their purses with easily earned guineas; whilst others who have no pecuniary motive for imposture are tempted to cheat, it would seem, solely by a desire for notoriety. _Second Theory._--The persons at a seance are the victims of a sort of mania or delusion, and imagine phenomena to occur which have no real objective existence. _Third Theory._--The whole is the result of conscious or unconscious cerebral action. These two theories are evidently incapable of embracing more than a small portion of the phenomena, and they are improbable explanations for even those. They may be dismissed very briefly. I now approach the "spiritual" theories. It must be remembered that the word "spirits" is used in a very vague sense by the generality of people. _Fourth Theory._--The result of the spirit of the medium, perhaps in association with the spirits of some or all of the people present. _Fifth Theory._--The actions of evil spirits or devils, personifying who or what they please, in order to undermine Christianity and ruin men's souls. _Sixth Theory._--The actions of a separate order of beings, living on this earth, but invisible and immaterial to us. Able, however, occasionally to manifest their presence; known in almost all countries and ages as demons not necessarily bad, gnomes, fairies, kobolds, elves, goblins, Puck, &c. _Seventh Theory._--The actions of departed human beings--the spiritual theory _par excellence_. _Eighth Theory._--(_The Psychic Force Theory_).--This is a necessary adjunct to the 4th, 5th, 6th, and 7th theories, rather than a theory by itself. According to this theory the "medium," or the circle of people associated together as a whole, is supposed to possess a force, power, influence, virtue, or gift, by means of which intelligent beings are enabled to produce the phenomena observed. What these intelligent beings are is a subject for other theories. It is obvious that a "medium" possesses a _something_ which is not possessed by an ordinary being. Give this _something_ a name. Call it "_x_" if you like. Mr. Serjeant Cox calls it Psychic Force. There has been so much misunderstanding on this subject that I think it best to give the following explanation in Mr. Serjeant Cox's own words:--