The generally accepted theory which has been employed to account for this coincidence is that the soul, thus torn suddenly and prematurely from the body, retains more of the material elements of the body than it does when death is the result of gradual disintegration and the natural separation of the material from the immaterial. It is thought that the physical elements thus retained temporarily by the spirit enable it to make itself visible to the living, as well as to perform certain feats of physical strength attributed to some spirits. This is very plausible at first glance, and in the absence of any facts to the contrary might be accepted as the true theory. But, as before intimated, there are exceptions to the supposed rule. It is not true that all ghosts are those of persons who have died violent deaths. On the contrary, many of the best authenticated ghosts are of persons who have died at a good old age and in the due course of nature. Moreover, there is nothing to distinguish the one class of ghosts from the other, although it is true that those who have met death by violence far outnumber the others. This theory, therefore, accounts for nothing. Nevertheless, the fact that the majority of ghosts are of those who belong to a particular class must possess some significance. Now, if we can discover some state of facts which appears to accompany all, or to precede all, ghostly phenomena, a great point will be gained, and the real significance of the other facts may become apparent. In looking the field over with this end in view, the first fact which forces itself upon our attention, and which seems to be universal and to possess a veritable significance, is that _all phantasms of the dead are of those who have died under circumstances of great mental stress or emotion_. No one whose death was peaceful and quiet, no one who left this life with no unsatisfied longing or desire present in the mind at the time of death, ever projected a phantasm upon the living objective world. Again, the strength, persistency, and objectivity of the phantasm seem to be in exact proportion to the intensity of the emotion experienced at the moment of death. It will thus be apparent why it happens that ghosts of those who have died violent deaths more frequently "revisit the glimpses of the moon" than those whose deaths have been less tragic and less calculated to inspire an intense desire or emotion. The murdered man feels, at the supreme moment, an intense longing to acquaint the world with the circumstances of his "taking off;" and he conceives the thought of reproducing the scene on the spot until its significance is understood and the murderer is brought to justice. The result is a haunted house; and those whose nerves are strong enough to withstand the shock may nightly witness a realistic reproduction of the tragedy. This may continue for days, months, or even years, but invariably ceases when the object is accomplished.