The very opposite objection comes from the side of religion.  These things we learn, are spiritual mysteries into which men must not inquire.  This is only a relic of the ancient opinion that he was an impious character who first launched a boat, God having made man a terrestrial animal.  Assuredly God put us into a world of phenomena, and gave us inquiring minds.  We have as much right to explore the phenomena of these minds as to explore the ocean.  Again, if it be said that our inquiries may lead to an undignified theory of the future life (so far they have not led to any theory at all), that, also, is the position of the Dreadful Consequences Argufier.  Lastly, “the stories may frighten children”.  For children the book is not written, any more than if it were a treatise on comparative anatomy.

The author has frequently been asked, both publicly and privately:  “Do you believe in ghosts?” One can only answer:  “How do you define a ghost?” I do believe, with all students of human nature, in hallucinations of one, or of several, or even of all the senses.  But as to whether such hallucinations, among the sane, are ever caused by psychical influences from the minds of others, alive or dead, not communicated through the ordinary channels of sense, my mind is in a balance of doubt.  It is a question of evidence.

In this collection many stories are given without the real names of the witnesses.  In most of the cases the real names, and their owners, are well known to myself.  In not publishing the names I only take the common privilege of writers on medicine and psychology.  In other instances the names are known to the managers of the Society for Psychical Research, who have kindly permitted me to borrow from their collections.

While this book passed through the press, a long correspondence called “On the Trail of a Ghost” appeared in The Times.  It illustrated the copious fallacies which haunt the human intellect.  Thus it was maintained by some persons, and denied by others, that sounds of unknown origin were occasionally heard in a certain house.  These, it was suggested, might (if really heard) be caused by slight seismic disturbances.  Now many people argue, “Blunderstone House is not haunted, for I passed a night there, and nothing unusual occurred”.  Apply this to a house where noises are actually caused by young earthquakes.  Would anybody say:  “There are no seismic disturbances near Blunderstone House, for I passed a night there, and none occurred”?  Why should a noisy ghost (if there is such a thing) or a hallucinatory sound (if there is such a thing), be expected to be more punctual and pertinacious than a seismic disturbance?  Again, the gentleman who opened the correspondence with a long statement on the negative side, cried out, like others, for scientific publicity, for names of people and places.  But neither he nor his allies gave their own names.  He did not precisely establish his claim to confidence by publishing his version of private conversations.  Yet he expected science and the public to believe his anonymous account of a conversation, with an unnamed person, at which he did not and could not pretend to have been present.  He had a theory of sounds heard by himself which could have been proved, or disproved, in five minutes, by a simple experiment.  But that experiment he does not say that he made.