Cillier’s list

Complexity is the result of a rich interaction of simple elements that only respond to the limited information each of them is presented with. When we look at the behaviour of a complex system as a whole, our focus shifts from the individual element in the system to the complex structure of the system. The complexity emerges as a result of the patterns of interaction between the elements.

1. Complex systems consist of a large number of elements. This is necessary but not sufficient. The grains of sand on a beach do not interest us as a complex system; interaction is vital.
2. Said interaction is fairly rich; every element in the system influences and is influenced by quite a few others.
3. The interactions themselves are non-linear, which guarantees that small causes can have large results, and vice versa.
4. The interactions usually have a fairly short range. As a result, it can be enhanced, suppressed or altered.
5. There are loops in the interactions. The effect of any activity can feed back onto itself, sometimes directly, sometimes after several intervening stages. This feedback can be positive (enhancing, stimulating) or negative (detracting, inhibiting)..
6. Complex systems are usually open systems that interact with their environment. It is often difficult to define the boundary of a complex system.
7. Complex systems operate under conditions far from equilibrium. There has to be a constant flow of energy to maintain the organisation of the system and its survival.
8. Complex systems have a history. Not only do they evolve through time, but their past is co-responsible for their present behaviour.
9. Each element in the system is ignorant of the behaviour of the system as a whole, it responds only to information that is available to it locally.

Note: this is a summary of the original see Complexity and Post-Modernism