Abstract
Modern natural science followed Galileo’s proposals regarding ontology, epistemology and methodology, limiting investigation to a few measurable properties of bodies by the adoption of the experimental method. Force appeared as a specialization of the traditional concept of efficient cause within the new science of Mechanics, which was soon able to incorporate practically all branches of physics. The concept of system had been introduced into scientific vocabulary in the seventeenth century and the limitations of the mechanistic approach in physics emerging by the end of the nineteenth century prompted Bertalannfy to deeply re-elaborate it as System Theory. This permitted him to complement the analytic outlook with a rigorous characterization of the notion of organized totalities. This could be applied to life sciences and several other scientific domains, allowing rigorous treatment of traditional concepts such as finality, and new concepts like complexity and interdisciplinarity.