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Home > Dictionary of Science Quotations > Scientist Names Index P > Karl Raimund Popper Quotes > Refutation

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Karl Raimund Popper
(28 Jul 1902 - 17 Sep 1994)

Austrian-British philosopher of science remembered for his writings on theory of scientific method.


Karl Raimund Popper Quotes on Refutation (4 quotes)

>> Click for 40 Science Quotes by Karl Raimund Popper

>> Click for Karl Raimund Popper Quotes on | Criticism | Falsification | Idea | Knowledge | Science | Scientific Method | Test | Theory | Truth |

It is easy to obtain confirmations, or verifications, for nearly every theory—if we look for confirmations. Confirmations should count only if they are the result of risky predictions... A theory which is not refutable by any conceivable event is non-scientific. Irrefutability is not a virtue of a theory (as people often think) but a vice. Every genuine test of a theory is an attempt to falsify it, or refute it.
— Karl Raimund Popper
Conjectures and Refutations: The Growth of Scientific Knowledge (1963), 36.
Science quotes on:  |  Attempt (94)  |  Conception (63)  |  Confirmation (15)  |  Ease (29)  |  Event (97)  |  Falsification (7)  |  Genuine (19)  |  Non-Scientific (4)  |  Prediction (67)  |  Refutation (10)  |  Result (250)  |  Risk (29)  |  Test (96)  |  Theory (582)  |  Verification (20)  |  Vice (15)  |  Virtue (55)

The difficulties connected with my criterion of demarcation (D) are important, but must not be exaggerated. It is vague, since it is a methodological rule, and since the demarcation between science and nonscience is vague. But it is more than sharp enough to make a distinction between many physical theories on the one hand, and metaphysical theories, such as psychoanalysis, or Marxism (in its present form), on the other. This is, of course, one of my main theses; and nobody who has not understood it can be said to have understood my theory.
The situation with Marxism is, incidentally, very different from that with psychoanalysis. Marxism was once a scientific theory: it predicted that capitalism would lead to increasing misery and, through a more or less mild revolution, to socialism; it predicted that this would happen first in the technically highest developed countries; and it predicted that the technical evolution of the 'means of production' would lead to social, political, and ideological developments, rather than the other way round.
But the (so-called) socialist revolution came first in one of the technically backward countries. And instead of the means of production producing a new ideology, it was Lenin's and Stalin's ideology that Russia must push forward with its industrialization ('Socialism is dictatorship of the proletariat plus electrification') which promoted the new development of the means of production.
Thus one might say that Marxism was once a science, but one which was refuted by some of the facts which happened to clash with its predictions (I have here mentioned just a few of these facts).
However, Marxism is no longer a science; for it broke the methodological rule that we must accept falsification, and it immunized itself against the most blatant refutations of its predictions. Ever since then, it can be described only as nonscience—as a metaphysical dream, if you like, married to a cruel reality.
Psychoanalysis is a very different case. It is an interesting psychological metaphysics (and no doubt there is some truth in it, as there is so often in metaphysical ideas), but it never was a science. There may be lots of people who are Freudian or Adlerian cases: Freud himself was clearly a Freudian case, and Adler an Adlerian case. But what prevents their theories from being scientific in the sense here described is, very simply, that they do not exclude any physically possible human behaviour. Whatever anybody may do is, in principle, explicable in Freudian or Adlerian terms. (Adler's break with Freud was more Adlerian than Freudian, but Freud never looked on it as a refutation of his theory.)
The point is very clear. Neither Freud nor Adler excludes any particular person's acting in any particular way, whatever the outward circumstances. Whether a man sacrificed his life to rescue a drowning, child (a case of sublimation) or whether he murdered the child by drowning him (a case of repression) could not possibly be predicted or excluded by Freud's theory; the theory was compatible with everything that could happen—even without any special immunization treatment.
Thus while Marxism became non-scientific by its adoption of an immunizing strategy, psychoanalysis was immune to start with, and remained so. In contrast, most physical theories are pretty free of immunizing tactics and highly falsifiable to start with. As a rule, they exclude an infinity of conceivable possibilities.
— Karl Raimund Popper
'The Problem of Demarcation' (1974). Collected in David Miller (ed.) Popper Selections (1985), 127-128.
Science quotes on:  |  Alfred Adler (3)  |  Falsification (7)  |  Sigmund Freud (66)  |  Marxism (3)  |  Metaphysics (30)  |  Methodology (8)  |  Psychoanalysis (37)  |  Refutation (10)  |  Theory (582)  |  Truth (750)

There can be no ultimate statements science: there can be no statements in science which can not be tested, and therefore none which cannot in principle be refuted, by falsifying some of the conclusions which can be deduced from them.
— Karl Raimund Popper
The Logic of Scientific Discovery (1959), 47.
Science quotes on:  |  Conclusion (120)  |  Deduction (49)  |  Falsification (7)  |  Principle (228)  |  Refutation (10)  |  Statement (56)  |  Test (96)  |  Ultimate (61)

[Great scientists] are men of bold ideas, but highly critical of their own ideas: they try to find whether their ideas are right by trying first to find whether they are not perhaps wrong. They work with bold conjectures and severe attempts at refuting their own conjectures.
— Karl Raimund Popper
'The Problem of Demarcation' (1974). Collected in David Miller (ed.) Popper Selections (1985), 118-119.
Science quotes on:  |  Attempt (94)  |  Boldness (6)  |  Conjecture (22)  |  Greatness (34)  |  Idea (440)  |  Refutation (10)  |  Scientist (447)  |  Work (457)  |  Wrong (116)


See also:
  • 28 Jul - short biography, births, deaths and events on date of Popper's birth.

Carl Sagan Thumbnail In science it often happens that scientists say, 'You know that's a really good argument; my position is mistaken,' and then they would actually change their minds and you never hear that old view from them again. They really do it. It doesn't happen as often as it should, because scientists are human and change is sometimes painful. But it happens every day. I cannot recall the last time something like that happened in politics or religion. (1987) -- Carl Sagan
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- 40 -
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- 30 -
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