region of pure mathematics, would write himself down belated. But if we admit that experience only can prove or disprove the possibility, we must further recognise that the proof which we are seeking is not likely to be salient or irresistible. We can hardly imagine any single incident which would give us satisfactory proof of the survival of a human personality. The proof, or disproof, must be in its nature cumulative. At a certain stage of the accumulation we may say, "The facts are, no doubt, not inconsistent with the hypothesis of the agency of the dead; but there are other interpretations in the present state of our knowledge equally adequate and at least equally probable." That is the stage at which our enquiry would seem now to have arrived. We have accumulated a large number of observations and experiments, open to various interpretations, but open amongst others to this particular interpretation, that they indicate in some fashion the presence of "dead" men and women. The man who at the present stage of the enquiry invites us, on the strength—or weakness—of the evidence so far available, to acclaim the proof of human immortality, may be doing serious injury to his own cause. But the other man who, because our present ignorance does not enable us to decide what is the true meaning of these elusive "seemings," condemns the whole enquiry as abortive, has surely no title to speak in the name of Science.
In the chapters which follow I shall aim at presenting fair samples of the evidences which have
