3.1 Commonly recognised systems

Firstly there are commonly recognised systems that are convenient to think of as existing ‘out there’. Such systems are widely acknowledged either because they are deliberately created (a stock control system, a computer system, for example); or because they are fairly discrete, naturally occurring phenomena that have long since been delineated and analysed by scientists (the nervous system and the solar system for example); or just because they are popularly referred to as systems in a vague though useful way (the legal system and the economic system are examples).

In general, such systems are based on widely shared perceptions. While this popular naming of recognised systems may be convenient and useful where the situation is merely complicated or its purpose is largely uncontroversial it can often hide the fact that the situation is very complex and that different people have very different perspectives on its purpose or indeed only have a partial view of one aspect of the wider system.