In this article, the author briefly summarise the characteristics of the science of complexity or post- Bertalanffy General Systems. The author discusses the shift from considering systems as acquiring properties due to their explicit or supposed design, to self-organised, emergent systems. Characteristics, approaches to modelling and interventions to change vary in nature with the post-Bertalanffy Systemics. While new suitable models and approaches are under study in sciences, such as physics, chemistry, biology, mathematics, engineering, and neurosciences, the author detects significant backwardness when dealing with the complexity of social systems and related problems that are developing in the post-industrial age. These problems include economic crises, security, defence, privacy, managing prisons, and supporting development. Such social problems are inadequately faced by using classical Bertalanffy's systemic concepts or by simply transposing models and changing the meaning of variables. This inadequacy is based on the underestimation of the peculiarities of Human Systems that consist of complex interactions that allow coherence and are also cognitive, informal, learning, evolutionary, ecological and non-governable Luhmannian subsystems. The non-cultural or low-cultural accessibility of the approaches considered by the science of complexity contribute to this inadequacy. Finally, the author presents some comments on how the science of systems may further evolve by considering new types of systems and systemic properties such as systemic fields and quantum systems. He speculates about some possible future understanding of human social systems.
