Georg Ivanovas From Autism to Humanism - systems theory in medicine

3. Epistemology

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3.4 Heinz von Foerster’s decidable and undecidable questions

Sound reasoning is much easier than the autistic-undisciplined thinking suggests. The only precondition is that the relation between different logical levels is understood, about axiomatic suppositions and their logical deduction.

Heinz von Foerster presented a simple semantic form, which makes the structure of this logical process easy to understand. He deduced axiomatic problems by distinguishing so-called decidable and undecidable questions (Foerster/Bröcker: 1-12). A decidable question is the question is: “Can the number 6893284534286 be divided by 7?” With some calculation it is possible to answer this question. It is, in a way, already answered when it is posed. A decidable question has an inherent answer independent of whether we find this answer immediately, after some reflection or even if it is impossible to answer that question at the present moment . ‘How many degrees (in Co) are on the dark side of the Pluto?’ is as decidable as the question ‘How much money did you spend in the new fashion shop?’ The criterion for a decidable question is not that it is answered or that it is answered truly. The criterion is that there is a definite answer to the question.

Undecidable questions are of a totally different nature. The question ‘what is happiness?’ cannot be decidedly answered. According to certain criteria we only find a subjective answer. A Christian might say that it is to live to the satisfaction of god, something possible with some effort. A biologist will regard it as genetically determined (Reichhardt 2006). A neuroscientist may say that it is a “glowing (of) left prefrontal cortex and (a) becalmed amygdala” (Flanagan 2003), or a stimulation of the award centre, or a complex neuro-biochemical process (Phillips 2003c). For a psychologist it might be a cultural problem connected to money (Diener cited in Bond 2001). Social scientists might see happiness as an issue of life style and geography (Bond 2003). A pessimist will hold it for an unattainable target, and for an addict it might be just a question of the next injection.

How an undecidable question is decided depends on many factors and no choice is compulsory. Therefore, von Foerster defined the decision itself as a metaphysical act, whereas the decision of a decidable question is just a logical operation.

When we look now at definitions of health and disease, we find a lot of decidable and undecidable questions. The question which germ causes tuberculosis, AIDS or SARS is as decidable as the question which substance has the strongest effect as bronchodilatator.

More difficult to comprehend is the fact that the diagnosis as such, the definition of a disease is an undecidable question. A pneumonia can be clearly defined as an inflammation of the lungs caused by certain bugs or other factors. Also tuberculosis, AIDS and SARS are somehow clearly defined. But there is no necessity to diagnose in this way. If the aim of the diagnosis would be to describe the state of the immune system allowing infections, then the name of a bug or the description of a local pathophysiological pattern would be of minor importance. On a logical level it makes no difference to establish a diagnosis according to emotional processes (as a psychoanalysist would do), according to supposed energetic patterns (acupuncturist) or the forces some spiritual healers take for granted. All these different strategies have their advantages and disadvantages. The choice depends rather on culture, practicability and available therapeutic tools (chap. 3.8). The choice as such is, however, a metaphysical choice. It happens according to the knowledge and the belief of a certain observer.

When we hear that a patient suffers on ‘psychoanangastic disorder with schizoid traits’, we learn little about the patient (he probably is a little strange), but we learn a lot about the one who makes the diagnosis, namely that he is obliged to a certain way of seeing and classifying mental disorders. But the very same is true with the diagnosis of epicondylitis (some pain at the elbow without any causal or functional reference), with pneumonia (certain clinical symptoms and/or alterations of the x-ray) or with rheumatoid arthritis (a certain typical swelling of the joints).

When an undecidable question is decided, the following questions become decidable. That is, every diagnosis consequentially implies a schedule of predetermined examinations and therapies. If ADHD is seen as a cerebral disease, the consequences are different as if it seen as an expression of environmental factors. When gastritis is regarded as a disease caused by a germ it will be treated differently as when it is seen as an expression of a certain emotional state..

The logical implications of such a decision are far reaching. This shall be demonstrated with a question from chaos-theory “How long is the coast of the British island?” It is a typical undecidable question. The answer is: It depends on the ruler. The finer the measuring ruler the longer is the coast, finally becoming infinite. It is a metaphysical act to decide on a ruler. The decision may depend on necessities, habits or anything else, but there is no must to decide it in one way or another. If only one ruler is allowed we call it nowadays a paradigm (chap. 3.10).


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