[lit-ideas] Re: falsifiability falsified?
- From: wokshevs@xxxxxx
- To: lit-ideas@xxxxxxxxxxxxx, Donal McEvoy <donalmcevoyuk@xxxxxxxxxxx>
- Date: Sun, 3 Feb 2008 18:03:26 -0330
I don't think we need to make a meal out of P's views on falsification. Surely
the essential points are two:
1. given (if p then q) and q, p may still be false.
2. given (ip then q) and not-q, it follows that not-q.
Hence:
Falsification tells us something that mere corroboration does not and cannot.
Walter O
MUN
Quoting Donal McEvoy <donalmcevoyuk@xxxxxxxxxxx>:
>
> Somewhat belated reply with my comments marked** (btw, I find it hard to
> take seriously her claim that her criticisms of Popper are a product of
> having read him â??carefullyâ?? â?? as we may see)â?¦
>
>
> Apropos our recent discussion, here's something from EDGE. The editors
> asked leading thinkers what they had changed their minds about, and
> received this answer from Rebecca Goldstein in the Harvard Philosophy
> Department:
> -----
>
> Said Popper: The criterion of the scientific status of a theory is its
> falsifiability.
>
> For most scientists, this is all they need to know about the philosophy
> of science. It was bracing to come upon such a clear and precise
> criterion for identifying scientific theories.
>
> **It is clear enough as an idea but, as Popper emphasises, it is â?? like
> many such criterions â?? not precise in its application:- there will be
> borderline and difficult cases.
>
> And it was gratifying to
> see how Popper used it to discredit the claims that psychoanalysis and
> Marxism are scientific theories. It had long seemed to me that the
> falsifiability test was basically right and enormously useful.
>
> But then I started to read Popper�s work carefully, to teach him in my
>
> philosophy of science classes, and to look to scientific practice to see
> whether his theory survives the test of falsifiability (at least as a
> description of how successful science gets done). And I�ve changed my
> mind.
>
> **The idea that Popperâ??s theory must itself be falsifiable is plausible but
> is mistaken - mistaken because the kind of logical-methodological
> considerations Popper offers are not themselves testable by observation; they
> are not descriptive-empirical claims but prescriptive-methodological ones.
> For instance, the view that a scientist should aim at increasingly
> falsifiable theories is not something that can either be confirmed or refuted
> by observation; it is a prescription as to how science ought best to be done
> â?? and its worth as a prescription is not undermined by showing that a class
> of persons among the class we would typically call â??scientistsâ?? do not
> adhere to the prescription. No more than the prescription that scientists
> should not fabricate â??dataâ?? etc. is undermined by those class of
> scientists who do fabricate data etc.
>
> For one thing, Popper�s characterization of how science is practiced
> -ââ?¬â??
> as a cycle of conjecture and refutation ââ?¬â??- bears little relation to
> what
> goes on in the labs and journals. He describes science as if it was
> skeet-shooting, as if the only goal of science is to prove that one
> theory after another is false.
>
> **No, this is another canard: for Popper the over-riding aim of science is
> interesting truth and it is therefore not as if the only goal of science is
> to prove falsity. What he maintains is that there is no direct way to prove
> we have the truth i.e. there is no such thing as verification. The best we
> can do is to rigorously test our theories for errors or falsity and if they
> survive these tests then perhaps they may be true. This process of conjecture
> and refutation is potentially neverending.
>
>
> But just open a copy of Science. To pick
> a random example: ââ?¬Å?In a probabilistic learning task, A1-allele carriers
>
> with reduced dopamine D2 receptor densities learned to avoid actions
> with negative consequences less efficiently.ââ?¬Â? Not, ââ?¬Å?We tried to
> falsify
> the hypothesis that A1 carriers are less efficient learners, and
> failed.� Scientists rarely write the way that Popper says they should,
>
> and a good Popperian should recognize that the Master may have
> over-simplified the logic of theory testing.
>
> **That they do not write in a Popperian way would not show that Popperâ??s
> â??logic of theory testingâ?? is wrong. Here the writer teeters again on
> confusing the a prescriptive methodology such as Popperâ??s with a
> descriptive one. This is a common confusion. It is true to say that there was
> once a marked tendency for scientific papers to be written in the inductive
> style or format and this tendency may still be prevalent. It has however been
> criticised as misleading by, for example, Sir Peter Medawar; and this
> criticism has allegedly lead to some reform. But it would be naïve to take
> the use of an inductive style or format of presentation as showing that
> proper scientific method is therefore inductive; all it shows is that there
> is a prevalent house-style that perhaps reflects an underlying mistake as to
> how scientific knowledge is obtained. Thirdly, much scientific writing does
> conform to Popperian strictures â?? and the example given as to allele
> carriers does not obviously go against a Popperian view, for at the same
> time as the experiment may be presented as confirming a certain hypothesis it
> is also a failed attempt at a refutation of that hypothesis. How it is
> presented is secondary to the overriding logic that even the apparent
> confirmation is only pro tem and that a future refutation may yet be devised.
> Thatâ??s Popperâ??s central point here.
>
> Also, scientists don�t, and shouldn�t, jettison a theory as
> soon as a
> disconfirming datum comes in.
>
> **Popper has never suggested that they necessarily should and for a number of
> reasons: the writer talks of â??oversimplifiedâ?? but to ascribe this view
> to Popper is not merely â??oversimplifiedâ?? it is a complete
> misrepresentation of Popperâ??s actual views. Views which we are asked to
> believe are the result of reading Popper â??carefullyâ??.
>
> As Francis Crick once said, ââ?¬Å?Any theory
> that can account for all of the facts is wrong, because some of the
> facts are always wrong.� Scientists rightly question a datum that
> appears to falsify an elegant and well-supported theory, and they
> rightly add assumptions and qualifications and complications to a theory
> as they learn more about the world.
>
> **To repeat: it is not part of Popperâ??s views to deny the gist of this
> (though he would avoid obscurantist talk of things like â??a datumâ??).
> However, there comes a point when such questioning of an apparent refutation
> is no longer part of a properly critical approach but instead is an evasive
> manoeuvre or â??immunising strategemâ??. Where this point comes is not
> something that can be decided by a criterion of any sort â?? it involves a
> (fallible) judgment given the state of the (critical) debate.
>
> As Imre Lakatos, a less-cited (but
> more subtle) philosopher of science points out, all scientific theories
> are unfalsifiable.
>
> **This is somewhere where Lakatos and Popper part company. There is an
> interesting paper by Lakatos, and one by Putnam with a similar thrust, in
> Popperâ??s Schilpp volume â?? together with Popperâ??s somewhat withering
> replies [â??everything Professor Lakatos touches seems to sprout numbered
> sub-divisionsâ?? i.e. heâ??s over-subtle; â??Professor Putnam is leader of
> the younger generation of logicians while I am a tottering old metaphysician;
> but Professor Putnam has not done his homeworkâ?? (from memory)].
>
> **I donâ??t think it can be said that Lakatos or Putnam offer anything very
> conclusive in favour of the view that â??all scientific theories are
> unfalsifiableâ?? or even the view that they are typically so.
>
> **The underlying issue might be put like this. We have a theory T, we have an
> observation O, we have initial conditions IC, and we have background
> knowledge BK. Say the theory T is â??All swans are whiteâ??, and the IC are
> â??Here is a swanâ??. Then, given T and the IC, we may deduce â??Here is a
> white swanâ??. But say O is that in fact â??Here is a black swanâ??. O is
> incompatible with T (contra Putnam, it is incompatible with T aside from any
> IC). Something therefore has to give. But what?
>
> **If O is true then T is false. If T is true then O cannot be correct. What
> Popper says is that we therefore have to decide where we attribute blame. We
> can blame T and say T is false. But we can also blame O and say that the
> apparent observation is nevertheless incorrect â?? and we can do this by
> doubting the truth of our O or of our BK. For example we could say O was the
> product of a hallucination or was a one-off freak that resulted from some
> error in the conduct of the experiment [this is why, methodologically, we
> usually demand that a refutation be part of a reproducible effect: see LDF].
> Or we could say that O is mistaken because while what was observed looked
> like a swan it was not in fact a swan as closer examination would show: that
> is, our BK needs revising to mark a more sophisticated distinction between
> what is a swan and what merely looks like one. The upshot is, as Popper has
> pointed out from the beginning, that a falsification can always
> be evaded.
>
> **The question is whether evading falsification is (a) universal or typical
> scientific practice and (b) good or proper scientific practice. Popper
> answers (a) and (b) in the negative and maintains that Lakatosâ??s elaborate
> examples of possible evasive manoeuvres fall well short of showing the
> contrary (and indeed are far-fetched).
>
> The ones we take seriously are those that lead to
> ââ?¬Å?progressiveââ?¬Â? research programs, where a small change
> accommodates a large swath of past and future data. And the ones we abandon
> are those that lead to ââ?¬Å?degenerateââ?¬Â? ones, where the theory gets
> patched and re-patched at the same rate as new facts come in.
>
> **Perhaps ironically Lakatos had appropriated the idea of â??research
> programmesâ?? from Popper who in the 1950s did work on the role of what he
> termed â??metaphysical research programmesâ?? and their importance for
> scientific research; for example in setting a kind of framework for the kind
> of explanation scientists seek [one that, say, involves indivisible particles
> and not, say, witches]. Popper does not like what Lakatos has done with this
> and other ideas of his â?? but, that said, there is no reason he would
> disagree with the very broad thrust of Lakatosâ?? view as expressed in the
> above paragraph, though he would put it quite differently and regards
> Lakatosâ?? way of putting it as quite tendentious in a mistaken way.
>
> Another problem with the falsifiability criterion is that I have seen it
> become a blunt instrument, unthinkingly applied.
>
> **Is this seriously Popperâ??s fault or a serious criticism of the criterion?
> You may as well criticise the inventor of a medicine because it is so
> successful that some doctors over-prescribe it.
>
> Popper tried to use
> it to discredit not only Marxism and Freudianism as scientific theories
> but also Darwinââ?¬â?¢s theory of natural selection -ââ?¬â?? a position
> that only a
> creationist could hold today.
>
> **This is another poor argument from Harvardâ?? Popper is criticised for
> holding a position that â??only a creationist could holdâ??. Popperâ??s
> position is far removed from creationism and the author does not mention an
> important, short paper Popper wrote where he â??recantedâ?? his previous
> views. In fact, all he does is modify them so as to avoid the impression that
> his view is that Darwinism has no scientific content. The key thing is to
> distinguish two aspects of Darwinism:- (a) where it functions as
> â??metaphysical research programmeâ?? that suggests what kind of explanation
> in principle would be acceptable; (b) where a specific explanation of a
> Darwinian kind is offered. In the form of (b) Darwinian explanations may be
> testable â?? indeed there are often competing Darwinian explanations and a
> search for tests to decide between them. In the form of (a) Darwinism is
> barely testable â?? even though its success in the form of (b) reflects well
> on it
> as a research programme, this does not mean that programme is itself
> testable. This distinction is quite crucial and frequently overlooked.
>
> I have seen scientists claim that major
> theories in contemporary cosmology and physics are not ââ?¬Å?scienceââ?¬Â?
> because they can�t think of a simple test that would falsify them.
>
> **And I have seen attack ships off the something coast of Orion. What kind of
> argument is being offered here from Harvard? The truth is that some of these
> theories are like Darwinism in form (a): they may have all kinds of
> attractions but are they testable? If not, they may â?? like Darwinism in
> form (a) â?? be of great scientific interest and the subject of much
> â??scientificâ?? speculation yet not themselves be scientific claims because
> they are as yet not testable. Of course, just as some people may think the
> testable of character of Darwinism in form (b) means form (a) is
> â??scienceâ??, so some may think that because certain theories are of great
> â??scientificâ?? interest that they must be science even if they are not
> testable. Among the virtues of Popperâ??s approach is to explain why this is
> not the best way look at things while admitting that certain currently
> untestable theories may be of great interest to those interested in science
> and indeed
> there are cases where it is hard to draw the line.
>
> You�d think that when they are faced with a conflict between what
> scientists really do and their memorized Popperian sound-bite about how
> science ought to be done, they might question the sound bite, and go back and
> learn more than a single sentence from the philosophy of science.
>
> **Equally you might think the author would, when she saw some obvious
> conflict between scientific practice and â??sound-biteâ?? Popper, go back and
> learn whether the sound-bite accurately reflected Popperâ??s actual views.
>
> But such is the godlike authority of Popper that his is the one theory that
> can never be falsified!
>
> **While maintaining his theory of science is not itself falsifiable by
> observation, Popper does admit that there are certain logically possible
> developments that would render his theory uninteresting and beside the point
> e.g. if we could develop drugs that meant people could only come up with
> interesting and true scientific theories and never uninteresting or false
> ones. Also he jibes Lakatos as to a situation where Popper would give up his
> views if the empirical world were to behave in certain ways: see Schilpp.
>
> Finally, I�ve come to think that identifying scientificality with
> falsifiability lets certain non-scientific theories off the hook, by
> saying that we should try to find good reasons to believe whether a
> theory is true or false only when that theory is called ââ?¬Å?science.
>
> **But Popperâ??s theory implies no such thing i.e. it does not imply that
> outside the field of what is testable by observation there can be no such
> thing as rational or critical evaluation of competing alternatives â?? his
> own largely metaphysical work is engaged in just such an enterprise of
> rational/critical evaluation. This is just incompetence from the author or
> deliberate aunt-sallying.
>
> It
> allows believers to protect their pet theories by saying that they
> can�t
> be, and shouldn�t be, subject to falsification, just because
> they�re
> clearly not scientific theories.
>
> **Even if one accepts an inductivist view of science, they would be able to
> protect their pet theories in the same way i.e. as not science or open to
> inductive verification. Falsificationism canâ??t prevent such a manoeuvre and
> it not a worthwhile criticism of it that it cannot.
>
> Take the theory that there�s an
> omnipotent, omniscient, beneficent God. It may not be a scientific
> hypothesis, but it seems to me to be eminently falsifiable; in fact, it
> seems to have been amply falsified.
>
> **By what it is â??amply falsifiedâ?? we are not told. By bad things in the
> world? Hmm. Problematic as the existence of â??bad thingsâ??may be for those
> who maintain God is all-good and all-powerful, that would not necessarily
> mean that observing their existence â??amply falsifiedâ?? such a view in a
> scientific sense â?? for it could do so only if we say that if God is
> all-good and all-powerful then we may deduce that there cannot exist anything
> bad, and therefore observation of anything bad falsifies the claim. But is
> such a deduction itself a given, or can we interpret the claim so that it
> does not necessarily follow? I suggest people can, whether plausibly or not,
> interpret the claim of an all-powerful and all-good God so that it is
> compatible with any observable state of affairs â?? in which case it cannot
> be falsified, never mind â??amply falsifiedâ??.
>
> But because falsifiability is seen
> as demarcating the scientific, and since theism is so clearly not
> scientific, believers in religious ideologies get a free pass.
>
> **It doesnâ??t give them a free pass â?? they give themselves a free pass.
> Quite different.
>
> The same is true for many political ideologies. The parity between scientific
> and nonscientific ideas is concealed by thinking that there�s a simple
> test
> that distinguishes science from nonscience, and that that test is
> falsifiability.
>
> **This last claim is not substantiated and rests on at least two
> misconceptions: (a) that the application of falsifiability as a criterion is
> always â??simpleâ?? â?? the idea may be simple, but the application of the
> criterion may not; (b) that the criterion implies that there is no
> â??parityâ?? between scientific and non-scientific ideas â?? it doesnâ??t, it
> simply points out that the difference lies in whether the ideas are testable
> by observation or not.
>
>
> Donal
> Bah humbug Harvard
>
>
>
>
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