"There are correspondences in the principles which govern the behavior of entities that are intrinsically widely different. These correspondences are due to the fact that they all can be considered, in certain aspects, "systems," that is, complexes of elements standing in interaction. [It seems] that a general theory of systems would be a useful tool providing, on the one hand, models that can be used in, and transferred to, different fields, and safeguarding, on the other hand, from vague analogies which often have marred the progress in these fields."