Though the physical eyesight of the primitive being is as good and clear as that of the civilised being, this alone is not enough. Sensing can take place, but the knowledge of the detailed truth or reality of the sensed object is totally out of the question in situations where one does not have memories of previous corresponding or related experiences that can act as a greater or smaller material of previous knowledge through which one, to a correspondingly greater or smaller extent, can recognise or identify the new experience. Behind every sensory impression a meeting takes place between a force emanating from the individual's deepest layer of consciousness and an ingoing force from the outer influence on the senses of the individual. At its strongest the force emanating from the individual constitutes the phenomena you know as "concentration". When you concentrate your thoughts, it is in reality only in order to be able to clear up a problem that is mystical or unknown to you. This concentration of thoughts is the same as mobilising all the experiences you have in your consciousness that are related to the problem. Concentration is thus a method by means of which you try to understand the unknown by means of what you already know. That this is the case is established as fact through the circumstance that in a case where you cannot find in your thoughts or memory experiences related to an unknown problem, the same problem will be as mystical and problematic as broadcasting or any of the other technical and scientifically most modern wonders are for the human being from the jungle. All sensing will thus be the same as reactions resulting from the meeting of known and unknown phenomena with our memories, which means, their meeting with the reactions of our previous experiences. Everything that reacts with our senses, whether it be our sight, hearing, smell, taste or feeling, is quite unknown to us until the moment it gets into contact with our previous experiences. Our faculty to sense, and thereby our faculty to understand, will thus depend on how great a material of experience our memory represents. The more experiences we possess, the easier, deeper and quicker do we sense new experiences in the same field, while the opposite is the case in every field where there are very poor or a total lack of previous experiences.