A man dies of a contagious disease; months after his death, aye, years – a bit of clothing, an object touched by him during his sickness, may communicate the disease to a person more physiologically sensitive than the persons around him, while having no effect upon the latter. And why should not an idea, a thought exercise the same influence? Thought is no less material nor objective than the imponderable and mysterious germs of various infectious diseases, the causes of which are such a puzzle for science. Since the mind of a living person can so influence another mind that the former can force the latter to think and believe whatever it will – in short, can psychologize that other mind, so can the thought of a person already dead. Once generated and sent out, that thought will live upon its own energy. It has become independent of the brain and mind which gave it birth. So long as its concentrated energy remains undissipated, it can act as a potential influence when brought into contact with the living brain and nervous system of a person susceptibly predisposed. The unhealthy action thus provoked may lead the sensitive into a temporary insanity of self-delusion, that quite clouds the sense of his own individuality. The morbid action thus once set up, the whole floating group of the dead man’s thoughts rushes into the sensitive’s brain, and he can give what seems test after test of the presence of the deceased and convince the predisposed investigator that the individuality of the "control," "guide," or communicating intelligence is thoroughly established.