ABSTRACT
Everything is a system or a component of a system. This chapter defines a concrete system as a composite thing such that every one of its components is changeable and acts on, or is acted on by, other components itself. A CES model is unwieldy in practice for requiring the knowledge of all the parts of the system and of all their interactions, as well as their links with the rest of the world. The state space method, like the CES model, can be used everywhere, from physics to sociology to the humanities. Beware the purely economic models of the economy: being largely false, they are likely to have disastrous practical consequences—consequences of ignoring the systemic approach and adopting some sectoral approach instead. A chemical system of this kind may be characterized as a system whose components are chemicals varying in numbers for being engaged in reactions with one another.
