"Most men have extraordinary vanities which have carefully concealed from their fellow men. Such is the case of this victim, believing that it is his dear departed aunt who speaks to him, he hears the demon harping over and over again on one string, like this: 'The true grandeur of your character and personality is now recognized by the world. Really you are a king. Vast riches are your just deserts? Unlimited wealth and power. As present, they are fraudulently withheld from you. So as I direct and you will be guided to them. But, remember that the world is against you. Confide in no one? Listen only to my instructions, and do unfalteringly what I have you to do.' And so on. Everyone Can Resist and Conquer Evil Impulses.
"By the time, the poor victim realizes the true nature of his familiar spirit, the demon's power over him and his acts in too great to be overcome by the victim's unaided efforts. His secret vanities and desires have developed enormously, and when the demon finally prescribes criminal acts as the means of realizing his ambition, his brain and hands automatically perform these acts, though the real perpetrator is the demon in the case.
"One reason why most people are so incredulous respecting the existence of demons is their habit of denying the existence of any intelligent force which may be without a material form. If they could once see the devil, hoofs and horns and tail, they would believe in him." They find it difficult to accept the existence of 'personal devils'  That are invisible, merely bundles of qualities? But none the less potent for evil. 