Georg Ivanovas From Autism to Humanism - systems theory in medicine
Bateson, a forerunner in the study of network pathologies distinguished two main mechanisms:
- monotone change, continuous increase or decrease
- to fix a value of a variable (Bateson, 1988: 119).
A pathology of the first type (monotone change) is the symmetric and complementary schismogenesis (chap. 4.2). It is, for example, seen when the negative feedback mechanism between Th1 and Th2 is not interrupted. Experience tells us that it takes months or even years until chronic diseases arise after the occurrence of the first symptoms. Much quicker is the development in Systemic Inflammatory Response Syndrome (SIRS). An inflammatory cascade which might lead to sepsis within hours or days.
The second network pathology (fixing a variable) is more difficult to conceive. A first step towards its understanding is that a rigid subsystem might contribute to a decline in the robustness of the whole system. The subsystems of biological systems are potentially regenerative, that is, they prevent exponential runaways due to positive feedback-mechanisms. To be regenerative a subsystem (as the Th1/Th2 relation) has to be connected with other subsystems through cybernetic feedback loops.(Th1 and Th2 depend on interleukin-4 and interleukin-12 and so on). If in such a system, due to outer influences, one variable is held constant other variables are necessarily changed. Or as Ashby said: “To prevent change in the superficial variables is to promote change in the more profound” (cited in Bateson 1988: 120).
After some time such a change will spread through the whole system leading to a different homeostasis. Bateson defines such a change as a kind of learning (Bateson 1972: 440-447). As a consequence of this change positive feedback loops and unexpected runaways will occur after some time (Bateson 1972: 330-331).
This hypothesis implies that modern medicine which often aims at holding variables stable tends to induce network pathologies. As so often in medicine, such a hypothesis would be difficult to prove. An example of the correctness for this assumption is the analysis of polytraumatized soldiers of the battles of Trafalgar and Waterloo. It revealed that the survival rate was then about the same as in today’s intensive care, despite all drugs and technology. The main reason for why current intensive care does not prove better is the high incidence of sepsis (Singer/Glynne 2005), the typical example of a runaway (De la Rosa et al 2008).
Sepsis became one of the leading causes of death in the Western world in a time when also allergies, which are also nothing else than an exponential runaway, increase. That is, there must be mechanisms in these societies inducing network pathologies.