Despite the criticism of Karl Popper's falsifiability theory for the demarcation between science and non-science, mainly pseudo-science, this criterion is still very useful, and perfectly valid after it was perfected by Popper and his followers. Moreover, even in his original version, considered by Lakatos as “dogmatic”, Popper did not assert that this methodology is an absolute demarcation criterion: a single counter-example is not enough to falsify a theory; a theory can legitimately be saved from falsification by introducing an auxiliary hypothesis. Compared to Kuhn's theory of revolutions, which he himself later dissociated from it transforming it into a theory of “micro-revolutions,” I consider that Popper's demarcation methodology, along with the subsequent development proposed by him, including the corroboration and the verisimilitude, though imperfect, is not only valid today, but it is still the best demarcation methodology.
