A magickal concept that can be compared to the idea of radio waves which are composed of two parts, the energy of the radio wave itself and the content (such as music) that is carried by the wave. Some magicians will create a psychic shield that is more of a filter than a mirror or block. This will allow the pure energy to get through while anything negative, such as a curse, is blocked. Some healers also use filters so they can interact with the energy of another while preventing any illness from entering their aura or body.