Falsifiability

:This page discusses how a theory or assertion is "falsifiable" ("disprovable" opp: "verifiable"), rather than the non-philosophical use of "falsification", meaning "counterfeiting." The idea comes from the work of the philosophers Sir Karl Popper and Ernest Gellner.

Criticism

Thomas Kuhn’s influential book The Structure of Scientific Revolutions argued that scientists work within a conceptual paradigm that determines the way in which they view the world. Scientists will go to great length to defend their paradigm against falsification, by the addition of ad hoc hypotheses to existing theories. Changing one's 'paradigm' is not easy, and only through some pain and angst does science (at the level of the individual scientist) change paradigms.

Related Topics:
Thomas Kuhn - The Structure of Scientific Revolutions - Paradigm

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Some falsificationists saw Kuhn’s work as a vindication, since it showed that science progressed by rejecting inadequate theories. More commonly, it has been seen as showing that sociological factors, rather than adherence to a strict, logically obligatory method, play the determining role in deciding which scientific theory is accepted. This was seen as a profound threat to those who seek to show that science has a special authority in virtue of the methods that it employs.

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Imre Lakatos attempted to explain Kuhn’s work in falsificationist terms by arguing that science progresses by the falsification of research programs rather than the more specific universal statements of naïve falsification. In Lakatos' approach, a scientist works within a research program that corresponds roughly with Kuhn's 'paradigm'. Whereas Popper rejected the use of ad hoc hypothesis as unscientific, Lakatos accepted their place in the development of new theories.

Related Topics:
Imre Lakatos - Universal statements

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Paul Feyerabend examined the history of science with a more critical eye, and ultimately rejected any prescriptive methodology at all. He went beyond Lakatos’ argument for ad hoc hypothesis, to say that science would not have progressed without making use of any and all available methods to support new theories. He rejected any reliance on a scientific method, along with any special authority for science that might derive from such a method. Rather, he claimed, ironically, that if one is keen to have a universally valid methodological rule, anything goes would be the only candidate. For Feyerabend, any special status that science might have derives from the social and physical value of the results of science rather than its method.

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Following from Feyerabend, the whole "Popper project" to define science around one particular methodology—which accepts nothing except itself—is a perverse example of what he supposedly decried: a closed circle argument. The Popperian criterion itself is not falsifiabile.

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Moreover, it makes Popper effectively a philosophical nominalist, which has nothing to do with empirical sciences at all.

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Although Popper's claim of the singular characteristic of falsifiability does provide a way to replace invalid inductive thinking (empiricism) with deductive, falsifiable reasoning, it appeared to Feyerabend that doing so is neither necessary for, nor conducive to, scientific progress.

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From scientists

Many actual physicists, including Nobel Prize winner Steven Weinberg and Alan Sokal (Fashionable Nonsense), have criticized falsifiability on the grounds that it does not accurately describe the way science really works. Take astrology, an example most would agree is not science. Astrology constantly makes falsifiable predictions -- a new set is printed every day in the newspapers -- yet few would argue this makes it scientific.

Related Topics:
Steven Weinberg - Alan Sokal - Fashionable Nonsense - Astrology

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One might respond that astrological claims are rather vague and can be excused or reinterpreted. But the same is true of actual science: a physical theory predicts that performing a certain operation will result in a number in a certain range. Nine times out of ten it does; the tenth the physicists blame on a problem with the machine -- perhaps someone slammed the door too hard or something else happened that shook the machine. Falsifiability does not help us decide between these two cases.

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In reality, of course, theories are used because of their successes, not because of their failures. As Sokal writes, "When a theory successfully withstands an attempt at falsification, a scientist will, quite naturally, consider the theory to be partially confirmed and will accord it a greater likelihood or a higher subjective probability. ... But Popper will have none of this: throughout his life he was a stubborn opponent of any idea of 'confirmation' of a theory, or even of its 'probability'. ... the history of science teaches us that scientific theories come to be accepted above all because of their successes."

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