It is not only a philosophical concern to draw a sheer dividing line between science and pseudo-science, but also a point of political and social significance. The accertance of a theory by the public, support for empirical facts, even the high mathematical proofs which David Hume put forth and the high mathematical probability of a theory were views held up to the twentieth century; they have been disproved, hence left aside, however. The last criterion postulated by karl Popper is refutability. It stubbornly ignores scientific theories, hence deliberately neglecting flexibility and modifiability of theories. In such conditions, scientists formulate a rescue hypothesis. Criticizing a theory is not to diminish it by refutation (as Popper does).
Significant criticism is always constructive; there will come no better theory without refutation of the previous one.
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