EN
Recognition of the duality and symmetries of economic motion offers researchers a new concept. As in the sciences of the last century, the debate between 'causes' and 'objectives' dies down. The basic question today is not seemingly contradictory paradigms or logical rivalry among schools, but correct and easily measurable description of the movement. In seeking a simpler and more comprehensible explanation, the authors examine the mathematical methods of creating theories and models. For this reason, they examine the cycle model of Goodwin, which is accepted by both schools. The causal or teleological explanation and the criteria of costs and of output are equally satisfactory, and a realistic description of economic cycles is arrived at by analysing the calculation practice of a model that satisfies and is based upon both.