A few words--which many persons will read with amazement--must be added here on the subject of _Cui bono?_ Multitudinous vials of scorn have been poured out on the inanities of ordinary spiritualistic _séances_; and all research into such matters is rigidly boycotted in scientific circles as being unworthy of any intelligent individuals notice. Even when the President of the Royal Society himself, and others who are entitled to write F.R.S. or D.Sc. after their names, have been known to touch the accursed and degrading thing, they have been either ostracised or half-pardoned contemptuously. This attitude is based on the belief that occultism is an idle and vain form of mental activity, and cannot, with any reason, be expected to add anything to the stock of human knowledge or to produce results of service to mankind. _Cui bono?_ Why waste time in tomfoolery that can never be useful and may possibly lead feeble persons into the abyss of insanity? The defect of the attitude is that it is unscientific. The proudest claim of Science is that she deals with the Facts of the universe and gives her allegiance to Truth rather than to Opinion. But these features are the characteristics of every well-conducted sitting for the development of psychical manifestations. The search is for facts; and the object pursued is the attainment of truth. If, then, a leader of science denounce the sitting as being necessarily futile he does one of two things: either he disallows the proudest claim of Science; or he declares the limits of his own personal knowledge to be those of Fact and Truth. It has often happened that researches which appeared at the outset to be a mere waste of time have in the end been found productive of much practical and useful knowledge. The modern inquiries into the feasibility of speaking with the dead are a case in point. They have already brought the world of Science and Industry face to face with the possibility and near prospect of a command over Matter and Physical Force such as men have never hitherto enjoyed and such as must lead inevitably to the greatest advance of material prosperity that mankind has ever experienced. This may best be made clear by dealing with some concrete example. The lessons of the Great War, the utterances of expert authorities like Lord Montagu of Beaulieu, and the newspapers generally, have taught the public that the navigation of the air will be the great and dominating factor of the world’s progress in future. This need not be enlarged upon here. Everyone admits that the command of the air will solve the problem of intercourse between all the regions of the globe, and will bring in its train a vast improvement in all the arts of living and a greatly-widened distribution of natural wealth.