Philosophy Versus Science, And Vice Versa

I am not a scientist. What I mean by that statement is that I don't do science for a living. My academic background, however, is in epistemology, philosophy of science and other more mundane areas such as statistics and research methodologies. I am understandably concerned about statements such as one made recently by Professor Lawrence Krauss and echoed by others that philosophy has outlived its usefulness and has nothing more to do with science.

I have to disagree as this shows a fundamental misunderstanding of the relationship between philosophy and practical science – philosophy is about what science is, not how it is done on a daily basis. It is the way to determine the difference between science, pseudoscience and nonsense, a way of deciding whether what we think we know is related to reality or just an illusion or maybe a mistake.

Part of the problem comes from misrepresentation (not necessarily deliberate) of what philosophy of science is, and I will give as examples the two most popularly recognised thinkers in the area, Karl Popper and Thomas Kuhn.

I am frequently told that Popper was wrong to talk about falsification because scientists do not spend their time trying to demonstrate the falsehood of existing, accepted theories. Of course they don't. What scientists do is to try to extend the range of knowledge or to investigate anomalous observations which seem in conflict with established ideas.

The principle of falsification is what makes a theory scientific. If there is no possible experiment or observation that can prove a theory wrong then the theory is not part of science. Creationism is not science because all observations can be accommodated within the theory without disproving it, but evolution is science because it is possible to define something that would bring it into doubt (Dawkins' famous "rabbit fossils in pre-Cambrian strata", for example). The fact that the age of the universe has been continually revised by scientists over the centuries does not show that science is wrong, only that science builds on what it knows as more evidence comes in.

That brings us to Thomas Kuhn and scientific paradigms. The misrepresentations of Kuhn I hear most often are that he claimed that large parts of scientific knowledge are static until overthrown in a "paradigm shift", possibly because all the scientists welded to a theory have died or retired, and that his idea of "incommensurable" paradigms allows for relativism to creep into the evaluation of competing theories.

What Kuhn actually said about paradigms is that science operates on a consensus basis, with most scientists working to confirm the theory or to address anomalies. Sometimes  there will be anomalies which can't be explained, although the preponderance of evidence still supports the theory. There can come a time when the volume of anomalies reaches a point that it can be reasonable to assume that the theory has some fundamental flaw and that a replacement theory is required. This replacement need not completely depose what exists but rather provide a parallel theory that applies in certain specific conditions. An example is the extension of Newton's mechanics (which works very well for almost all observations) into the realm of the very small and very large where its predictive power was either poor or non-existent. This was indeed a paradigm shift, because a completely new way of thinking about the universe appeared. It should be noted that scientists didn't rush to forget all they knew – most of it still worked very well and the new discoveries did not falsify or refute what was known, just explained some of what it could not explain.

The charge of relativism was rejected by Kuhn. Yes, there can be competing theories which are totally contradictory, but this doesn't mean that they have equal value or credibility. Popper's falsification is one way of deciding between competing paradigms, but there is also the situation where one is supported by observation and experiment and the other requires all those observations to be ignored. I have been told that there is a theoretical basis for homeopathy but acceptance of this paradigm requires total rejection of the paradigms surrounding chemistry and physics. I should point out that homeopathy is a valid scientific hypothesis. It is possible to design experiments that can disprove it. They all do, so the paradigm can be rejected.

Quacks and pseudoscientists rely heavily on relativism, as if all theories should be given equal weight and standing. As the creationists say about evolution: "it's only a theory".

Philosophy is about language, how it is used and what it is used for. Science uses what is called "first order language" – it talks directly about what is observed. Philosophy uses "second order language" – it talks about what it means to say something and whether what is said relates to reality. Both are necessary – knowing things and knowing why and how we know them. It is the philosophy of science that allows us to trust science, and it isn't going to go away.

This article was published as the Naked Skeptic column in the March 2014 edition of Australasian Science