catallaxy files

catallaxy in technical exile

Warning, philosophers at work – Popper vs Lakatos

with 2 comments

John Quiggin and I have been exchanging notes on the philosophy and methodology of science as it applies to economics. The bone of contention is the claim that Laktos identified some problem with Popper’s views and improved upon them with his methodology of scientific research programs. That idea became influential among economists through the agency of Spiro Latsis (a student of Lakatos) and Mark Blaug, a prolific writer on the history of economics who became an advocate for the ideas of Lakatos.

There are at least two reasons to make a serious effort to get clear on this matter. That is why I have persisted with this task at the risk of being labelled a Popper fanatic or clone. One of the reasons is simply to set the record straight, to insist that the truth be told about Popper’s contribution instead of the mangled version of his ideas that quite a number of professional philosophers spread around.

The second reason is that some of Popper’s ideas form a powerful synergy with the leading ideas of the Austrian school of economics. At present the philosophical framework of discourses is an Achilles heel for the Austrians but the mainstream of philosophy is not much help. Popper’s ideas have been marginalised from that mainstream, in the way the the Austrians have been marginalised in economics. So the second reason for this debate is to make the connection between Popper and the Austrians.

In this post I will stick to the first point. The following text is my latest reply to John.

Taking up the discussion of Popper and Lakatos, John has referred to the broadly positive article on Popper in the Stanford Encyclopedia of Philosophy to support his view that Lakatos identified a serious problem with Popper’s account of scientific method. He has suggested that I should take the matter up with Stephen Thornton, the author of the article, and come back when I have provided arguments that induce Thornton to change his mind.

This confirms my original thought that John did not rely on his own judgement in this matter. This is entirely understandable because he is an economist, not a philosopher of science. Life is too short to check out every single assumption that we have to make to get through the day. How many of us go under the house to check the report of a structural engineer or a pest inspector? How many of us do an inspection of the floor bearers each morning before we proceed to the kitchen for our Weet Bix to ensure that dry rot or termites have not rendered the floor unsafe overnight? But how reliable is our professional philosopher in this instance?

The request to get the professional to change his mind is likely to be a difficult assignment because Thornton has already been challenged by a contributor to the Critical Rationalist email group which used to run as an offshoot of the Critical Rationalist website.

The Thornton piece was discussed by the group and he was offered some carefully formulated criticism of parts of the article. He broke off the exchange when he found that some points in his email to the individual were mentioned on the list and he chose to regard that as a misuse of private correspondence.

I got the feeling that he was not receptive to criticism. That is unfortunate because there are inconsistencies between the body of his article and the concluding criticism (which is drawn practically verbatim from Lakatos). That criticism simply falls over, and this can be demonstrated fairly easily.

So the situation at present is that John is resting his position on advice from a person who has recycled a criticism of Popper from another source, despite the fact that the criticism in question is (a) contradicted in another part of his own paper and (b) refuted in my piece on the ABC philosophy show.

Too much focus on demarcation

If Thornton wanted to demonstrate his grasp of the issues and his also critical acumen he could have challenged Popper’s view that the problem of demarcation between science and non-science is fundamental. In some ways that is beside the point, for example the contest between Newton’s theory and Einstein’s theory was arguably the most important scientific issue in modern times, but they are both scientific theories. So what could a theory of demarcation contribute to that debate?

Scientists expect their theories to be testable in the same way that car buyers expect the steering wheel to come as standard equipment, not something that is offered as a bonus or a selling point or an optional extra.

I can’t explain why Popper was so hooked on the idea that demarcation was fundamental. It could be the result of his own intellectual history because the demarcation problem was his point of entry to other (in my view more important) problems, like the matter of induction which the positivists wanted to use as the hallmark of science.

Conflating demarcation and the growth of knowledge

In his discussion of induction and demarcation it seems that Thornton has collapsed two different but related issues into one. He wrote “Popper repudiates induction and rejects the view that it is the characteristic method of scientific investigation and inference, and substitutes falsifiablility in its place”.

It will help to separate the two issues – one is the matter of demarcation and the other is the way that scientific knowledge grows. Popper and the positivists split on both issues:

1. On demarcation the split is between verification and falsification.
2. On the growth of knowledge the split is is induction vs the method of conjecture and refutation (trial and error).

Popper took issue with the verification criterion of meaning and he also (separately) took issue with the notion that knowledge grows by a process of induction (which has about five different definitions, just to confuse the issue, but Popper rejected all of them).

That is why it is so unhelpful to refer to Popper’s theory of knowledge as falsificationism.

Helpful comments from Thornton

Thornton did better when he wrote “Popper has always drawn a clear distinction between the logic of falsifiability and its applied methodology [falsification]…Thus, while advocating falsifiability as the criterion of demarcation for science, Popper explicitly allows for the fact that in practice a single conflicting or counter-instance is never sufficient methodologically to falsify a theory, and that scientific theories are often retained even though much of the available evidence conflicts with them, or is anomolous with them”.

He also did well in section 4 of the paper on the growth of human knowledge, where he emphasised the role of problems, the need for imaginative speculation disciplined by the tests of reason and evidence, the scientist as entrepreneur (an Austrian connection) etc.

For my money the central problem in epistemology is not demarcation but the need to reconcile the complementary roles and functions of problem-situations, tradition, evidence, logic, reason, mathematics, metaphysics, scrutiny of definitions, intuition and anything else that turns up in the mix. And Popper’s theories, taken together, do perform that process of reconciliation in contrast with foundational epistemologies of various kinds.

Strange criticism

In the light of the foregoing statements, especially this one “Popper explicitly allows for the fact that in practice a single conflicting or counter-instance is never sufficient methodologically to falsify a theory, and that scientific theories are often retained even though much of the available evidence conflicts with them, or is anomolous with them” it is strange to come to the following criticism at the end of the paper.

“As Lakatos has pointed out, Popper’s theory of demarcation hinges quite fundamentally on the assumption that there are such things as critical tests, which either falsify a theory, or give it a strong measure of corroboration.”

Lakatos claimed that but it is not the case because Popper clearly explained that falsification is inevitably conjectural (although some falsifications are so decisive that they are not really problematic in any practical sense). In principle, due to the theory-dependence of observations, all apparent refutations can be challenged or ignored and Popper’s position is not invalidated on that account.

After describing the discovery of Neptune as a triumph for Newton’s theory, by resolving an apparent anomaly, Thornton proceeded –

“Yet Lakatos flatly denies that there are critical tests, in the Popperian sense, in science, and argues the point convincingly by turning the above example of an alleged critical test on its head. What, he asks, would have happened if Galle had not found the planet Neptune? Would Newtonian physics have been abandoned, or would Newton’s theory have been falsified?”

The answer from Popper’s point of view is that Newtonian physics would not have been abandoned because there was no alternative theory of comparable scope to take its place. The anomalous planetary movement would be noted as an unresolved issue.

“The answer is clearly not, for Galle’s failure could have been attributed to any number of causes other than the falsity of Newtonian physics (e.g., the interference of the earth’s atmosphere with the telescope, the existence of an asteroid belt which hides the new planet from the earth, etc). The point here is that the ‘falsification/corroboration’ disjunction offered by Popper is far too logically neat: non-corroboration is not necessarily falsification, and falsification of a high-level scientific theory is never brought about by an isolated observation or set of observations.”

This is precisely what Popper himself pointed out in his discussion of the Duhem problem. Popper agreed with the problem that Duhem posed and he agreed with Duhem’s response the problem – there is no logical fix, that is just the way the world is, get over it and proceed with theory development and testing in the hope that the picture will become clearer.
In case it helps I wrote a thesis on the Duhem problem under the supervision of Alan Chalmers. Warning, slow-loading word file.

“Popper’s distinction between the logic of falsifiability and its applied methodology does not in the end do full justice to the fact that all high-level theories grow and live despite the existence of anomalies (i.e., events/phenomena which are incompatible with the theories).”

That statement is simply false as Thornton acknowledged in the passage quoted above. Popper’s distinction does complete justice to the situation. This is an example of Popper’s own ideas being used as a bogus criticism of his own position.

Sad conclusion

So what is the outcome of all this? John Quiggin put his faith in a professional philosopher to tell him the truth about Popper’s theories and he was let down. The shocking truth of the matter is that the rank and file of professional philosophers cannot be relied on for a straight feed on Popper’s ideas. More research is required, but what discipline should be recruited for the task?

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Written by Admin

November 15, 2006 at 1:18 pm

Posted in Uncategorized

2 Responses

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  1. Rafe:
    >The Thornton piece was discussed by the group and he was offered some carefully formulated criticism of parts of the article. He broke off the exchange when he found that some points in his email to the individual were mentioned on the list and he chose to regard that as a misuse of private correspondence.

    What a loser. Was the CRist involved the redoubtable Ken Hopf?

    Daniel Barnes

    November 16, 2006 at 8:30 am

  2. A couple of points

    1. I found the Thornton piece a couple of days ago when I thought I’d check with the Stanford Encyclopedia to see that my views weren’t way out of line. As it turned out, Thornton’s view was the same as mine, but we arrrived at this position independently.

    2. It seems to me that your quarrel isn’t with me, or with Thornton, or with Lakatos, but with Popper. As you tell it, he misunderstood his own thought on falsifiability as a demarcation criterion, thereby misleading me, as well as Thornton and Lakatos. Since he’s not with us any longer, he can’t resolve inconsistencies in his own work, so it seems that appeals to Popper as an authority are doomed to failure.

    John Quiggin

    November 16, 2006 at 9:52 pm


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