If the influence is so strong from a living person, the obsession of a dead person, of a spirit, is much stronger still. The dead person has no other means of expression, and so he seizes upon a weak person, a weak mind, and controls that. It is not that the soul enters into the body; the soul is much too large to do that; but it reflects itself upon the other soul. A spirit focuses itself upon the soul of another; the greater power holds the lesser.