Roll up, roll up! In the latest episode of The Philosofa, Omar and Helen talk science versus pseudoscience. They are joined in the studio by philosopher Professor Ken Gemes of Birkbeck University (returning in full form after episode one); recovering academic and author of award-winning popular science books, David Bodanis; and the economist, widely known for his bestselling and critically acclaimed critique of mainstream economics, Debunking Economics, and for publically predicting the 2008 financial crash, Professor Steve Keen.

In this play fight to the philosophical death, our panel takes on that old and impenetrable chestnut – the ‘demarcation problem’, which is the problem of how to differentiate between genuine science and its slightly shady, slightly slow cousin, wannabe science, or pseudoscience.

So who cares about the demarcation problem anyway? The fact of the matter is science affects just about every aspect of our lives. A huge amount of trust and authority is given to it.  All sorts of questionable things have gained legitimacy and influence by calling themselves a science.  So the question what is the genuine thing, and what is not, is important.

There has not always been a firm distinction between philosophy and science. It was not until the great propagandist for a new scientific method, Francis Bacon, wrote his Novum Organum in the 17th century, that science began to be thought of as something very different from philosophy.

So what is it? Among the many things that pop up in this fascinating philosophical tour de force, from back surgery to Yiddish mysticism, expect to hear the name Karl Popper. This giant looming luminary, who legend has it was once threatened with a poker by Ludwig Wittgenstein, was mainly concerned to show that certain things, like Marxism and classical Freudian psychoanalysis, which claimed to be scientific, were not. Popper argued that it is a misconception that science proceeds by confirming hypotheses and theories through the accumulation of supporting evidence. The problem with things like Marxism and psychoanalysis, he argued, is that their claims are so broad and vague that it’s just too easy to find confirmatory evidence for them. Rather, good science is about making specific and novel predictions and then attempting to falsify them. It is a matter of trying to find evidence to disprove, rather than prove, what you think, and a willingness to change your view if the evidence is against it. This view is known as ‘falsificationism’.

One of the major criticisms of Popper’s falsificationism came from philosopher and historian of science, Thomas Kuhn. In his The Structure of Scientific Revolutions, he argued that this is just not how real science works. Kuhn argued that there is rarely such a thing as decisive falsifications of scientific theories. Evidence can always be reinterpreted, explained away or simply shelved as an anomaly. When theories are dropped in science this is largely for sociological reasons to do with personal, cultural and political contingencies of the time.

So far we have only been talking about the hard sciences. What about the social sciences? The test case is economics. There is a Nobel Prize in Economic Science. Economic theories have been axiomatized and economics textbooks are full of mathematic theorems. But are the claims of economics falsifiable by Popperian standards? Can we conduct randomized controlled experiments in economics? Or should we think of economics as more like atmospheric physics or the science of the tides, where we have to allow a certain margin for error due to the complexity of causes and variables involved?

These are only some of the topics touched on in episode two. So get comfortable, have a listen and enjoy.