Under this general head he considers Animal Magnetism, what is known generally as mesmerism, the power, that is, to create hypnotic states in others; the phenomena of Telepathy "comprising numerous varieties, such as the transmission or penetration of thought, the exteriorization of the sensitiveness, psychometry, telepathy, clairvoyance or lucidity, etc.," and finally states "where physical matter appears to exert over animate beings, especially human beings, an action that does not seem to be explicable by any physical or chemical properties already known." He believes also that there is in human beings a radiating influence susceptible of being exercised at a distance over other animate beings or else upon inanimate objects. He finds in trance mediumship all the elements which enter into any hypnotic state. "The trance is produced and developed spontaneously, without the intervention of any visible operator, under the sole effect of the nervous and mental conditions in which the medium is placed, and among which the _belief in spirits_ and the expectation of their intervention would appear to play a considerable part."[82] The italicized words "a belief in spirits" are extremely significant. In the entranced personality there is the suggestion, already strongly established, that whatever is experienced during the trance will be due to spirit intervention or revelation. This introduces the element of expectant attention. We know on the physical side of what expectant attention is capable. It becomes a real factor in all faith healing; it may produce, either for the better or the worse, far-reaching changes in physical states and it is perfectly possible for such an expectant attention once fully in action in the trance--given of course, to begin with, the attitude and interests of the medium in a waking state--to create all the machinery of controls, revelation and the like, which characterize trance mediumship. [Footnote 82: Boirac, "The Psychology of the Future," p. 271.] Boirac finds, therefore, in spiritism a complex determined by certain particular nervous and mental states into which there enter, in one form or another, almost all the facts of abnormal psychology and he believes that science, faithful to the principle of economy, should consider the alleged phenomena of spiritism, until proved to the contrary, reducible to facts of the preceding orders. He does not call the spiritistic hypothesis impossible; he does believe it ought not to be called in until every other explanation has been examined and found inadequate and he is not inclined to believe that we have as yet exhausted other possible explanations.