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Monday, March 26, 2012

Swans, black and white

Here, in UCD, our lake houses 2 swans (He, a Cob and She, a Pen). They are white and often, as I pass them, I think of the philosophy of science, and I will explain the link. How do we know something is true?

That the sun rises in the east is a given. It happens every day since time immemorial and thus we can expect it to do so forever. It is a truth. That the truth is defined as something that can be seen time after time, was challenged by Karl Popper an Austrian philosopher. He argued that the truth was best observed from an opposite viewpoint. We do not attempt to show something to be true by means of endless philosophical machinations but rather we can show something to be false. No matter how often the sun rises in the east, we cannot be certain that, one day it will rise in the southeast or east-southeast and so on. However, if ever the sun rose in the east-southeast we could say for absolute certainty that the sun does not always rise in the east. The usual metaphor is the theory that all swans are white. They always have been and they always will be. And then, some explorers on Captain Cook’s antipodean expedition discovered black swans. Thus, according to Popper, the white swan theory was abolished instantly. He saw science progressing in a cycle of conjecture (‘all swans are white”) and refutation (‘we just found some black swans’).  That all sounds fine until one reads the works of an American philosopher, Thomas Kuhn. He argues that science existed at two levels. There was ‘normal science’ and ‘revolutionary’ science. Kuhn regarded the latter as a paradigm shift, a phrase often repeated since.

We used to believe that all swans are white but now we know better. Popper and Kuhn seem to be together at this point. However, whereas Popper believed that this was normal in science, Kuhn argues that this was not in fact normal. It was revolutionary. Kuhn believed that most science fell into this classification of ‘normal science, which was the opposite of revolutionary. Normal science simply defended conventional wisdom. In fact it vigorously defended it. Let us go back to the issue of ‘all swans are white”. The explorers, excited by their discovery, decide to write a scientific paper for the International Journal of Swan Science. The editor sends it out for review and both reviewers reject it, absolutely. One argues that these are not in fact swans at all although they might look like swans. The researchers are asked to conduct extensive genetic sequencing and to re-submit the paper if that is still justifiable. The second referee goes further and argues that indeed they may be swans but they are mutants arising from some pre-mobile phone mast radiation and that they will die off. Basically, the two naïve explorers thought that science was interested in new ideas. It is, provided that the sacred central theory is not challenged. And in this instance, the sacred theory of ‘all swans are white” was not about to be dumped on the basis of some unknown swanologists out in the antipodes. Careers and egos are built on the central dogma and upstart wannabe swanologists should respect that.

Kuhn is correct. Most scientific research is simply filling in gaps of our knowledge in relation to some large paradigm. Up until 10 years ago, we believed in the Central Dogma of Biology, that there was one gene for every protein. With the sequencing of the human genome, we now know that this is not true. That was revolutionary science. Now we populate our scientific papers with explanations of how it all works. That is normal science.

Challenging conventional wisdom is laden with risk to those who would dare to do so. It is not simply that your scientific papers might be rejected. You, yourself, may be pilloried. A classic case is that of Bjørn Lomborg, a Danish statistician who wrote a magnificent work: “The Skeptical Environmentalist”. For his sins he was castigated by the high priests of global warming and suffered disgrace by the relevant Danish scientific integrity watchdog, only to be re-habilitated by his own resolute pursuit of the truth. He now heads a highly prestigious global think tank The Copenhagen Consensus Center. Lomborg simply challenged the way that environmentalists express their concerns. For example, one leading pro-environmental NGO pointed out the spiraling costs of storm damage in the coastal regions of southeast USA. Year on year the economic impact grew and thus, the conclusion was that year on year, the weather was getting worse and storms were becoming more frequent and more severe. All Lomborg did was to show that the value of real estate in this region was growing year by year and moreover, the number of properties per hectare was also growing annually. When he adjusted for the value of properties per hectare, the effect was to show no increase. This is just one of many examples of his challenge to conventional wisdom. In human nutrition, there are many sacred tenets: “Breast is best”, “Obesity is the fault of an irresponsible food industry”, “ The large bowel colonic microflora are central to human health’ etc. To challenge any of these is not easy.  To do so labels one as an agenda laden crank who sees everything in a negative fashion. However, dissent is the oxygen of science and whereas as dogmatism may be suitable for religious and scientific movements, it has no place in science. The outlier is often more revealing that the mean.

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