What is the biomedical model #4

So far in this short series on the biomedical model, I have looked at three of its founding principles: specific aetiology, germ theory, and Cartesian Dualism. In this post we’ll examine one of the facets of modern medicine that is perhaps the most familiar and tangible concept for modern-day physiotherapists – objectivity and experimentation. In the previous post on Cartesian Dualism, I explored how the French 16th century philosopher René Descartes argued that there was no way to prove the existence of anything, because our dreams were so real we could never prove that we were not dreaming right now. What Descartes showed was that we could not trust our senses and that seeing was absolutely not believing. Like Ebenezer Scrooge seeing Marley’s ghost in Charles Dickens’ Christmas Carole, we are prone to be deceived by our senses, and we are always vulnerable to interpretations and impressions, memories, and values and beliefs that influence how we perceive what we think might be real. Consider this example;

If you show a first year undergraduate student a picture of a chest x-ray, they are likely to see patches of light and dark, wispy shadows, the occasional solid-seeming structure, and a few anatomical landmarks that they can name. A trained eye, however, will see immediately that the patient has a left apical pneumothorax, some collapse/consolidation of the left lower lobe, and some elevation of the left hemi-diaphragm. Both are looking at the same x-ray, but only one has been trained to interpret the tissue densities represented by the x-ray in a meaningful way. So the simple act of learning is, in some ways, the act of overcoming raw sensory data and giving it meaning.

Experimentation then, is necessary in order to remove, as much as possible, the bias that might come from people’s lived experience, social positioning, values and beliefs, learning and memory. Rene Descartes argued that to approach any kind of objectivity we needed to experiment with as many modalities, tools, and approaches as possible. And only then will we have reasonable confidence that what we are seeing is actually the truth and not some artefact of our imagination. When you consider how much experimentation takes place in modern-day healthcare – in the way that we differentially diagnose, analyse, test, hypothesise about causes, isolate variables, control for conditions, and monitor outcomes – you can see how powerful objectivity and experimentation have become in shaping biomedicine. But more than this, one of the distinguishing characteristics of a modern orthodox profession is that it holds to Western enlightenment beliefs about the importance of objectivity and experimentation. In contrast, those disciplines that shun this approach (think here of homeopathy, Traditional Chinese Medicine, and some aspects of chiropractic), remain ostracised and excluded from the mainstream. Objectivity and experimentation are more than simply strategies for corroborating facts then; they are tools for differentiation between those professions we can believe in and those we are told we should distrust.