The passion of fear is implanted in our nature for wise purposes. It prompts us to self defence and the avoidance of evil. It is excited into action by various causes, depending on the condition of the nerves in different constitutions, or in the same at different times. But when extended to imaginary objects of terror, fear becomes superstition, as by a sort of instinct, and has a direct tendency to cherish ignorance and credulity. Dr Franklin had no faith in apparitions and spectres, but he proposed to a friend, that the one which should die first, should return in spirit and visit the survivor; his friend died first, but his spirit never returned. The strong mind of Dr Samuel Johnson was not altogether free from agitation and embarrassment, when contemplating the question of the appearance of incorporeal spirits in our world. This great man said to Mr Boswell, his biographer, 'it is wonderful that 5000 years have now elapsed since the creation of the world, and still it is undecided whether or not there has ever been an instance, in modern times, of the spirit of any person appearing after death. All argument is against it, but all belief is for it.' Boswell suggested, as an objection, that if spirits are in a state of happiness, it would be a punishment to them to return to this world; and if they are in a state of misery, it would be giving them a respite. Johnson replied, that 'as the happiness or misery of spirits depends not upon place, but is intellectual, we cannot say, that they are less happy or less miserable, by appearing upon earth.' Johnson observed, that he makes a distinction between what a man may experience by the mere strength of his imagination, and what imagination cannot possibly produce. Thus, said he, 'suppose I should think that I saw a form, and heard a voice say, Johnson, you are a very wicked fellow, and unless you repent, you will certainly be punished; my own unworthiness is so deeply impressed upon my mind, that I might _imagine_ I thus saw and heard, and therefore I should not believe that an external communication had been made to me. But, if a form should appear, and a voice should tell me, that a particular man had died at a particular place, and a particular hour, a fact which I had no apprehension of, nor any means of knowing, and this fact, with all its circumstances, should afterwards be unquestionably proved, I should in that case be persuaded, that I had supernatural intelligence imparted to me.' Johnson related a story of a ghost, said to have appeared to a young woman several times, advising her to apply to an attorney for the recovery of an old house, which was done, and at the same time saying the attorney would do nothing, which proved to be the fact.