Pictorial examples from this text illustrate how, as desired, not form-identical but derived forms can be developed from a two- and three-dimensional structured original form (basal form) via intermediate forms (bridging forms). In the midline-orientated sensory constructions which unfold in the course of time, special, unique and surprising things appear - spontaneously, conspicuously and unexpectedly - through self-reflections. Part One concentrates on the phenomenon of symmetry, a phenomenon which could hardly be more manifold. Here, an object of knowledge was taken up which promised to overcome the fragmentation of science into individual disciplines, and of thinking and action into specializations that had become mutually intelligible. Part Two deals particularly with biological questions. It discusses points of contact between form-developing processes in nature and art that provide a theory of form, its development and its transformations. The collection of data on perception and knowledge with regard to the postulated reality of symmetry then leads to a further development of the evolutionary theory of symmetry in Part Three. Facts and problems of an evolutionary concept of symmetry in its applicability to many fields of dead and living nature, to the liberal arts and natural sciences, are presented here for discussion.