Page:The psychology of insanity (IA psychologyofinsa00hartiala).pdf/156

contradicted by experience. For example, it is impossible for a sane pauper to believe that he is a millionaire. In the lunatic, however, we have seen that this gross incompatibility with experience is frequently observed. Moreover, although in normal men beliefs dependent upon strong emotional prejudices are apparently insusceptible to argument and to any but the most flagrant contradictions presented by actual experience, yet this insusceptibility is not absolute. The opposing forces exert a slow erosive effect which in process of time produces a gradual alteration in the belief, and perhaps ultimately destroys it. An insane delusion, however, seems altogether fixed and immune to this action, and the processes described only serve to elaborate the defences with which it is hedged round. All these latter distinctions depend upon the cardinal factor of dissociation. In the lunatic dissociation has been carried to a degree which is incompatible with normal thought or behaviour, and mental processes are allowed to pursue their course altogether undisturbed by the contradictions presented by the facts of experience.