How can we tell science from nonscience?

By | September 9, 2012

So I have been reading this very interesting book called “Philosophy of Science: The Central Issues”. It has proven to be a nice reading so far and tries to share opinions on the questions we often ask our self. Like “what differs science from religion?” or “is there a demarcation between science and no science?”

The differentiation of science and pseudoscience is an interesting question often considered in philosophy of science, even though the problem might seem as unsolvable for the lack of agreement on its demarcation criteria. Although, ultimately what one considers to be the demarcation line probably tends to depend on his paradigm, experience and personal opinion, this question is “not a pseudo-problem of armchair philosophers, it has grave ethical and political implications” (Imre Lakatos).


Karl Popper










In 1953, Karl Popper gave a talk on his view on how there should be a demarcation criteria to distinguish science from pseudoscience. From his perspective, theories scientific status should be distinguished based on the criteria of testability/falsifiability. This means that a good theory should: be open to refutation; have testable predictions; no, or minimal ad-hoc reinterpretations. Also, as Karl Popper mentioned, the demarcation between science and pseudoscience is not a problem of meaningfulness, significance, truth or acceptability. In fact, his demarcation criteria was based on the correct usage of the inductiveness characterized by the standard scientific empirical methods. As expected, Popper’s view would eventually be criticized by other science philosophers such as Thomas Kuhn, Imre Lakatos and Paul Thagard. Although most of them had different perspectives, most of them seem to agree that the scientific legitimacy also depends on historical considerations.

Thomas Kuhn

Thomas Kuhn

Seventeen years later (1970), Thomas Kuhn claims that Popper’s view of science growth only applies to the occasional revolutionary parts of science. He argues that Popper was too concerned with the procedures through which science grows, by exploring the limitations of an accepted theory, and that all his classic tests had destructive outcomes which are rare in normal scientific development (revolutionary science). Kuhn believed that any demarcation criteria should apply to normal science and described it has being puzzle-solving activities, in which hypotheses are tested by using sets of rules of the theory to which they are bound. In this scenario, the failure of an hypothesis affects only the individual and not the theory itself.

Imre Lakatos

Imre Lakatos

A few years later (1973), Imre Lakatos also claimed that Popper did not separate science from pseudoscience, but the scientific method (falsifiability) from non-scientific method instead. He argued that, unlike Popper’s view, criticism can be constructive and science is, in fact, empirically progressive. This means that refutations are not the hallmark of empirical failure since scientists don’t often abandon a theory because facts contradict it. He also opposed to Kuhn’s perspective since he thought that “scientific revolutions are not sudden irrational changes in vision”. Although according to Latakos, a research program (not isolated hypothesis) can grow incrementally, it starts degenerating when “theory lags behind facts”. And here he underlines that since all programmes grow in uncertainty and anomalies, it is the unexpected predictions that make a programme accountable for such demarcation.

We all have our notion of what it is science and why we believe in a given theory. But given a good look at it, we can see the subjectivity in our own opinions. In the end of the day, we’ll still act as if we were optimistic scientists and think we can always achieve a greater knowledge!

Bibliography (Philosophy of Science: The Central Issues. 1998. Curd, M. and Cover, J.A. W.W. Norton.)

Leave a Reply