There is a tendencey to define systems as a composed totality of parts interrelated and with an objective, definition that leaves the theory of systems in very under level. System is a generating concept that transcends to component and its relations. The Theory of System is an intent theory and concept that has good exit in the processing of complexity.But it leaves even many empty. Regularly, by avoiding mechanism, the reversibility and the reductionism, fallsin others fields where the empire of the all ignores the part, the ones that constitute meetings, in reality,the unitas multiplex as oven field of the principle of the dialogica. The thougths systemic, as a construction concept and as an aptitude, a view, a form to think and work complexity, it has evolved since Bogdanov and Bertalanffy (that didnt prepare of e al todays mathematical progress to treat the complexity) to ours and by generating important ideas in several directions that try to comment in this article.