There are two actions of sense, which are in fact two actions of the whole being: expressiveness and responsiveness. The whole universe works on these two principles. As soon as the expressing spirit expresses itself, the responsive spirit receives its impression, just as a person whose picture is taken by a camera yields his impression when the camera is properly adjusted. If the camera is not rightly placed, there will be no image on the plate. If a spirit has a fondness for someone and desires to be in the thought of this beloved one all the time, always near him, then, just like a camera taking a photograph of someone, this unconscious spirit of man naturally takes the impression coming from that spirit.