When a person speaks, thinks or feels either harshly or kindly of another, it reaches the spirit of that one, either consciously or unconsciously, by the power of vibration. If we happen to be offended with someone and do not show it in speech or action, yet it still cannot be hidden, for the vibrations of our feeling will reach directly to the person in question, and he will begin to feel our displeasure, however far away he may be. The same is the case with our love and pleasure: however we may try to conceal it in speech or action, it cannot be hidden. This explains the old adage that even walls have ears, which really means that even the wall is not impervious to vibrations of thought.