The theory of complexity, which began to crystallize some 100 years ago and has been experiencing intensive development for over 30 years now, was created as an attempt to describe complex physical non-equilibrium systems. For some time, attempts have been made to apply its achievements to the description of processes taking place in the animate nature – functioning of organisms, creation of communities and ecosystems, from the simplest to those most complex – anthropogenic. In spite of the rather scary name, the principles on which the theory of complexity is based seem to be quite simple.

The animate nature, human communities, markets, nations, states, cultures and civilizations are a series of complex systems embedded within one another.

First of all – complex systems cannot be designed top-down. A complex system is not a watch or a plane, namely a complicated mechanism that must be designed by its designers down to the tiniest detail. A complex system designs itself through the interaction or evolution of its constituent parts. Secondly – each complex system is emergent, that is, the entire system is more than a sum of its components – the system’s behavior cannot be predicted if we know only the functioning principles of its individual parts. Thirdly – the increase in the size of the system entails the exponential growth of resources needed to maintain its functioning. Fourthly – complex systems are susceptible to sudden catastrophic collapses. Self-complicating of the system requires a continuous increase in the amount of available resources consumed in order to sustain it. Their depletion or such a change within the system which will weaken the rate of generating resources to sustain it cause it to fall into a state of instability. This state can end with its phase transition into another system or with a total catastrophic breakdown.

A complex system consists of individual elements that must be differentiated, remain in communication with each other, influence each other and adapt to changing circumstances. What determines the behavior and evolution of the complex system in time is the degree of diversity of its elements and the intensity of their interaction. Hardly differentiated elements, connected by simple relations, influencing each other in few ways and having limited possibilities of mutual adaptation, are not very dynamic. In the case of highly complex systems complicated relations, unlimited possibilities of influencing and the need for immediate adaptation may lead to a situation where elements of the system receive too much information from too many sources, which causes the system to plunge in chaos under the pressure of often contradictory signals.

The animate nature, human communities, markets, nations, states, cultures and civilizations are a series of complex systems embedded within one another. Why – let us ask – complex systems operate, develop and get complicated, eventually becoming even more complex? Because thanks to these processes they are more efficient in managing the resources available to them, using them to sustain and develop their complexity. And why are they breaking down? Because they encounter limits in the availability of resources used to sustain their existence as well as limits in the effective use of such resources. An example of this is the rivalry between dinosaurs and mammals – the sudden decline in the availability of resources, most likely associated with catastrophic climate change, deprived dinosaurs of their dominant position. Most of them have become extinct, some have become today’s birds. The world today is reigned by mammals – as physiologically more effective. So the collapse of one complex system can become the beginning of another.

The question arises here, is it possible to predict the directions of evolution, development and its associated threats to the functioning of complex systems? To some extent, of course, yes. By using its behavioral lenses, the human mind does so constantly, above all in relation to the immediate environment. However, when it comes to modeling and predicting the behavior of mutually embedded complex systems such as the animate nature and anthropogenic systems – human communities, tribes, markets, nations, civilizations and cultures – any serious attempt to describe this compounded complexity requires reference to attainments in behavioral science. Any simplifications made for the purpose of modeling reality may turn out quite revengeful when practical conclusions are drawn too hastily. Then, their implementations result in tangible losses or even put anthropogenic systems into a state of instability which may – but does not have to – end in a catastrophic collapse (something history witnessed more than once).