In the first episode of the film, we heard Sophie Ponta raise a deceptively simple question, what is science? Now, this question is more difficult than it may seem. Usually, science is regarded to be a special kind of knowledge. So that brings up the question, is scientific knowledge different from everyday knowledge? And if so, how can we distinguish the one from the other? In fact, scientific knowledge and everyday knowledge do indeed seem to differ in several respects. Everyday knowledge is practical, commonsensical, based upon everyday experiences. Scientific knowledge, on the other hand, is often highly counterintuitive, based upon imaginative ideas, and it usually involves a theoretical framework. Indeed, according to science, very little is what it seems to be. We can see the sun move from east to west, but science tells us it is we, or rather the earth beneath our feet that is moving. And even the elementary laws of motion themselves are highly counterintuitive. So in order to produce innovative work, scientists need to use, or even stretch their imagination. But of course, there's more to science than just strange ideas. Above all, theories need to be grounded on solid facts. They have to be able to account for all the relevant data, preferably in the simplest way possible. So here we have two poles of science. Imaginative ideas on the one hand, and solid facts on the other. Both are indispensable. Pure speculation does not produce science but neither does simply amassing facts. However, these general features of science are not sufficiently precise to distinguish science from other kinds of knowledge. In the previous century, many philosophers have struggled with the question, how to demarcate science from what they saw as pseudoscience? Perhaps, the best known example of such attempts is the one proposed by the Austrian-British philosopher, Karl Popper. Now, Popper's favorite targets were Karl Marx's theory of history, and Sigmund Freud's theory of psychoanalysis. Popper was profoundly impressed by the differences between their allegedly scientific theories on the one hand, and Albert Einstein's theory of general relativity on the other. Now, like Einstein's theory, both Marx's and Freud's theories are highly sophisticated. They're counterintuitive, and they can account for many facts. As Popper saw it, the main difference between those theories and that of Einstein, was that Einstein's theory was highly risky, in the sense that it predicted some specific phenomena that had never been observed before. According to Einstein theory, stars in the neighborhood of the sun would appear to be in a different position because of the bending of the light by the sun. Such an apparent change of position was completely unprecedented. However, this spectacular prediction was fully confirmed during the solar eclipse in 1919. As Popper pointed out, a failure to measure such a shift would have resulted in a rejection of the whole theory. Now compare this to psychoanalysis. According to Popper, the chief source of strength of psychoanalysis is capability to accommodate and even explain every possible form of human behavior, was in fact a critical weakness, for it entails that psychoanalytic theories are insufficiently precise to have negative implications, and are therefore immune to falsification. Therefore, Popper took falsifiability as his criterion for demarcating science from non-science. So, if a theory is incompatible with possible empirical observations, it is scientific. Conversely, a theory which is compatible with all possible observations is unscientific. Popper then did not agree with Ponta. Science does not revolve around the question, how you can establish something as true. The question is, how to establish something as false? As Popper argued, it is easy to obtain evidence in favor of virtually any theory. Universal statements such as, all swans are white, do not derive their strength from the fact that all swans observe so far turned out to be white, but rather from the fact that they forbid the occurrence of a swan that is black. Conversely, there is no way to falsify so-called existential statements. For example, statements that claim the existence of a green swan. The very fact that the next one I observe is either black or white, does not falsify my theory in any way. Every truly scientific theory done in Popper's view is prohibitive in the sense that it forbids particular events or experimental results. Now, of course, Popper was not naive. As he realized, methodologically, the situation is much more complex. After all, no observation or measurement is completely free from the possibility of error. Popper then explicitly allowed for the fact that in practice, a single conflicting outcome or event is never sufficient to falsify a theory. In fact, scientific theories are often retained, even though much of the available evidence conflicts with them. But that does not change the fact that in Popper's view, the scientific quality of a theory is determined by its prohibitive nature, rather than by the amount of supporting evidence. And that the essence of science is critical testing of one's ideas, rather than amassing support for them.
