It is clear that the above mentioned basic aspects have a very abstract meaning within the sketched abstract energy concept. It becomes obvious here that energy is a book-keeping quantity. Energy conservation only means that the energy number of a system does not change, if there are no interactions with other systems, or that the energy number in the systems involved in interactions change in such a way that the sum of changes is zero. It is important to note here also that the physics energy concept may not be viewed as an entity that causes changes. The physicist Auerbach(1913) provided this metaphor to indicate the appropriate status of energy: in the big firm of nature, energy is only the bookkeeping agency, the director entropy decides in which direction occurrences are to go.