We gradually discovered that the accounts of apparitions at the moment of death--testifying to a supersensory communication between the dying man and the friend who sees him--led on without perceptible break to apparitions occurring after the death of the person seen, but while that death was yet unknown to the percipient, and thus apparently due, not to mere brooding memory, but to a continued action of that departed spirit. The task next incumbent on us therefore seemed plainly to be the collection and analysis of evidence of this and other types, pointing directly to the survival of man's spirit. But after pursuing this task for some years I felt that in reality the step from the action of embodied to the action of disembodied spirits would still seem too sudden if taken in this direct way. So far, indeed, as the evidence from apparitions went, the series seemed continuous from phantasms of the living to phantasms of the dead. But the whole mass of evidence _primâ facie_ pointing to man's survival was of a much more complex kind. It consisted largely, for example, in written or spoken utterances, coming through the hand or voice of living men, but claiming to proceed from a disembodied source. To these utterances, as a whole, no satisfactory criterion had ever been applied. In considering cases of this kind, then, it became gradually plain to me that before we could safely mark off any group of manifestations as definitely implying an influence from beyond the grave, there was need of a more searching review of the capacities of man's incarnate personality than psychologists unfamiliar with this new evidence had thought it worth their while to undertake. It was only slowly, and as it were of necessity, that I embarked on a task which needed for its proper accomplishment a knowledge and training far beyond what I could claim. The very inadequate sketch which has resulted from my efforts is even in its author's view no more than preparatory and precursive to the fuller and sounder treatment of the same subject which I doubt not that the new century will receive from more competent hands. The truest success of this book will lie in its rapid supersession by a better. For this will show that at least I have not erred in supposing that a serious treatise on these topics is nothing else than the inevitable complement and conclusion of the slow process by which man has brought under the domain of science every group of attainable phenomena in turn--every group save this.