Super-normal gifts, in the view of our most experienced authority, are rare and elusive, and require patience, knowledge and discrimination on the part of the inquirer.[5] Sir William Barrett dissuades uninstructed persons from resorting to mediums; and it is clear that he desires the total elimination of the commercial element. We need to guard against self-deception, he thinks, even in people whose character is beyond reproach. (2) Sir Arthur Conan Doyle greatly dislikes the commercial element in mediumship. In a letter to _Light_[6] he pleads for the “training and segregation of mediums.” Like Sir William Barrett, he condemns the whole system of paying by results. “It is only when the professional medium can be guaranteed an annuity which will be independent of results,” he says, “that we can eliminate the strong temptation to substitute pretended phenomena when the real ones are wanting.” He points out that mediumship in its lowest forms is a purely physical gift, with no relation to morality. (3) Mr. J. Arthur Hill, as Sir A. Conan Doyle tells us,[7] has been for many years an invalid, stretched on his back in bed. A strong and athletic young man, he was suddenly reduced to absolute helplessness by a heart-wrench sustained while cycling up a hill. The volumes he has written under sad physical disabilities are among the most influential now read in Spiritualist circles, and their quiet, unfanatical tone commends them to outsiders. Mr. Hill, like the late Frank Podmore, whose place he has partly taken as the historian of the movement, has a thorough knowledge of the older literature and journalism, both American and British. He admits deliberate fraud on the part of professional mediums, and is sceptical with regard to “materialisation.” It is not unlikely, in his opinion, that sitters who await, in darkness and expectancy, the appearance of discarnate personalities, may “pass into a mental state not quite normal, and closely analogous to hypnosis.” Mr. Hill thinks it inevitable that doubt should linger in the mind when the financial element enters at all into mediumship, and he advises that this element should be eliminated as far as possible. He discusses very frankly the evidence obtained from non-professionals. “We have subliminal memory to deal with, and that is more difficult to exclude than ordinary fraud.” The best class of Spiritualist teachers are fully aware of the attitude of caution imposed upon them by the gradual progress of medical investigation into the workings of the unconscious mind.