critical rationalism blog

Stephen Hicks has posted a link to a survey of US philosophers to find out  how they ranked the books and articles of the 20th century.

Using the Philosophers’ Email Directory, we mailed our questionnaire to 5,000 teachers of philosophy. About 1,000 emails bounced back for mis-typed or obsolete addresses, 4,000 reached their targets. We received 414 survey replies, a healthy response rate of better than 10%. Since there are about 10,000 teachers of philosophy in North America, we had replies from 4% of the entire profession. At a confidence level of 80%, the survey has an error rate of plus or minus 3%, assuming that we reached a demographically representative group.

Not a very inspiring result. The Logic of Scientific Discovery just scraped in at equal 25th.

The top ten books cited:
1. Wittgenstein, Philosophical Investigations [179 citations]
2. Heidegger, Being and Time [134]
3. Rawls, A Theory of Justice [131]
4. Wittgenstein, Tractatus Logico-Philosophicus [77]
5. Russell & Whitehead, Principia Mathematica [64]
6. Quine, Word and Object [63]
7. Kripke, Naming and Necessity [56]
8. Kuhn, The Structure of Scientific Revolutions [51]
9. Sartre, Being and Nothingness [38]
10. Whitehead, Process and Reality [34]

This is something a bit different but closely related to the study of metaphysical research programs.  My friend Michael Giffin, another independent scholar in Sydney has made a deep study of metaphysical themes in modern literature, focussed on female novelists and the Australian Nobel Prizewinner Patrick White.

His latest book has just gone live as an Amazon e book, Female Maturity from Jane Austen to Margaret Atwood: When Bildungsroman Meets Zeitgeist.  One of the good things with these books is that you can preview 10% before you buy and that means you can form a fairly reliable opinion as to whether you want to read the whole thing or not.

Continue reading →

Writing about the Popperian “turns”provides an opportunity to acknowledge the work of Popper’s research assistants and editors who helped along the way. Think of them as the Sorcerer’s apprentices, or perhaps the elves in Santa’s toy factory. Joe Agassi’s book about his time in Popper’s workshop contains a photo of all the research assistants: himself, Ian Jarvie, Alan Musgrave, David Miller, Arne Petersen and Jeremy Shearmur. Feyerabend was supposed to be the first but he did not report for duty.

It would be nice to have a photo of Popper’s longest serving and most dedicated helper of all, the gracious Lady Popper, known as “Hennie” after her family name. Two other important helpers were his editors, Bill Bartley who finally got the manuscript of The Postscript out the door to the printer and  Mark Notturno who edited Popper’s last collections of papers and worked on his series of introductory lectures at the LSE.

I mention the helpers in connection with the “turns”; conjectural (or non-justificationist), objective, social and metaphysical because for good reasons or bad I tend to associate some of the helpers with some of the turns.

I have written about Bartley and his work on the conjectural or non-justificationist turn and put some of his work on line.  Of course all Popper’s helpers participated in the conjectural turn and Bartley was the one who made the most out of non-justificationism. Miller was strong in this respect as well, although Popper and others were not entirely satisfied with the way both Bartley and Miller developed critical rationalism.

Ian Jarvie was good on objective knowledge and his Concepts and Society was a book that I would have liked to write:)  He really nailed the social turn as well, see his beautiful book The Republic of Science: The Emergence of Popper’s Social View of Science.

Joe Agassi does beautiful things too but he has written too many books and his articles are too long for busy to people to read. I think of him as the metaphysical ghost in the Popperian machine, or  at least the person who did so much to keep metaphysics in the frame and not down the drain where the positivists wanted to send it.

Jeremy Shearmur was very helpful for me, starting with hospitality and introductions to local philosophers when I was in England in 1972. He also sent bundles of books including some by Talcott Parsons which enabled me to pick up the common ground of the early Parsons (up to 1937) with von Mises and Popper. And his book on the political thought of Karl Popper indicated the way that Popper’s ideas support classical liberalism despite the fact that they are usually interpreted to support the interventions of social democracy.

Radnitzky was not close to Popper (as far as I know) but he was a big helper with Bartley to promote the evolutionary approach (which is not among the list of four “turns” for some reason, I suppose I don’t want to describe everything that Popper did as a “turn”).

When Popper wrote Logik der Forschung the notion of truth was problematic and he avoided talking about it until Tarski developed the use of metalanguages to permit a formal statement of the correspondence theory of truth that was robust in terms of modern logic. A good place to find Popper’s take on this is in the 1962 Addendum to volume 2 of The Open Society and its Enemies. It is also explained clearly in one of his lectures on the philosophy of science that he delivered each year for a decade or so at the London School of Economics (not yet published).

He wanted to be able to say that scientists seek the truth (without ever knowing we have found it) and he also wanted to be able to form a critical preference for one theory that was better than another, especially nearer to the truth. He tried to go beyond the intuitive idea of getting nearer to the truth with a formal definition of ‘truthlikeness’ or‘verisimilitude’ that combined the ideas of both truth and content.

In Conjectures and Refutations (1963) he defined or formalized the content with reference to the logical consequences of theories. The idea was to compare the ‘truth-content’ of a theory, which is the class of true propositions which may be derived from it, with the ‘falsity-content’  which is the class of the theory’s false consequences.

I am not aware of anyone ever actually doing the sums for any live theories so it is difficult to know what it really means but the problem for Popper came a few years later in the the 1970s when his colleague Davaid Miller and others revealed fundamental defects in the  formal definition.

The details of the problems are explained in the Stanford Encyclopedia. The problems are (possibly) significant because verisimilitude was largely important in Popper’s system because of its application to theories which are known to be false. In this connection, Popper had written:

Ultimately, the idea of verisimilitude is most important in cases where we know that we have to work with theories which are at best approximations—that is to say, theories of which we know that they cannot be true. (This is often the case in the social sciences). In these cases we can still speak of better or worse approximations to the truth (and we therefore do not need to interpret these cases in an instrumentalist sense). (Conjectures and Refutations, 235).

The Stanford author (Thornton) explained that the deficiencies discovered by the critics  were seen by many as devastating, precisely because the most significant of these related to the levels of verisimilitude of false theories.

In 1974, Miller and Tichý, working independently of each other, demonstrated that the conditions specified by Popper in his accounts of both qualitative and quantitative verisimilitude for comparing the truth- and falsity-contents of theories can be satisfied only when the theories are true. In the crucially important case of false theories, however, Popper’s definitions are formally defective. For while Popper had believed that verisimilitude intersected positively with his account of corroboration, in the sense that he viewed an improbable theory which had withstood critical testing as one the truth-content of which is great relative to rival theories, while its falsity-content (if it exists) would be relatively low, Miller and Tichý proved, on the contrary, that in the case of a false theory t₂ which has excess content over a rival theory false t₁ both the truth-content and the falsity-content of t₂ will exceed that of t₁. With respect to theories which are false, therefore, Popper’s conditions for comparing levels of verisimilitude, whether in quantitative and qualitative terms, can never be met.

This had a strange result because people who had previously attached little importance to the  theory of verisimilitude suddenly came to see it as central to his philosophy of science, and consequently liked to think that the whole Popperian edifice had been subverted. I can recall the day in 1974 when a friend in Philosophy, a gentle and easygoing soul,  approached me with malicious glee to announce that Popper’s program was in ruins! This seemed strange, but who was I to argue with a professional philosopher?

In Realism and the Aim of Science Popper replied to criticism (pp xxxv to xxxvii) with the argument that the notion that successive theories may be better approximations to the truth is not damaged by the failure of a formal definition. Two examples were (1)  the progress from the earth-centred solar system to the sun-centred system with circular orbits to the system with elliptical orbits, and (2) the progress from Darwin’s ideas about heredity, to Mendel, to the steps that resulted in uncovering the genetic code.

“These examples show, I believe, that a formal definition of verisimilitude is not needed for talking sensibly about it.” (xxxvi)

He went on to expand on his view about the use and abuse of definitions.

I have often argued against the need for definitions. They are never really needed, and rarely of any  use, except in the following sort of situation: we may by introducing a definition show that  not only are fewer basic assumptions needed for a good theory but that our theory can exlain more than without the definition. In other words, a new definition is only of interest if it strengthens a theory.  I thought that I could do this with my theory of the aims of science…[this did not work]. But the widely  held view that scrapping this definition weakens my theory is completely baseless.

The assertion that my authority is damaged by this incident is obviously true, but I never claimed or wished to have any authority. The assertion that my theory is damaged has been advanced without even attempting to give a reason, and seems to me just incompetent.

From “Popper on the Differences between the Natural and the Social Sciences” in In Pursuit of Truth, Paul Levinson (ed), 1982.

Popper always sough to communicate with other philosophers, but he underestimated the neurotic element there would be in the reception of his highly boat-rocking ideas. A rationalist expecting rational responses, his ideas had the unintended consequence that people found them a threat and dealt with them by foisting interpretations on them, trying to pigeonhole Popper as part of some  wider entity that was thought to be under control – as, for example, debates internal to  logical positivism, a doctrine thought to have been superseded by Wittgenstein. Carnap abetted this tactic [with this paper “Testability and Meaning”]. The other interpretation was to dismiss him as some sort of renegade or crank, talented perhaps but flawed (insufficiently professional? [and not a good “club man”]). Hence consign his contribution to marginal status at the edge of the professional debate.” page 101

Problem: how did so many hard-working, bright and ambitious people manage to work on the philosophy and methodology of economics without producing much that is helpful for working economists and policy-makers? This became a growth area during the 1980s with more than a dozen books in the decade, two new journals and a round of conferences and the like.

This situation is summed up by Wade Hands in his retrospective survey of the field in Reflection Without Rules: Economic Methodology and Contemporary Science Theory, 2001. He concluded that the Received View of positivism/logical empiricism/Popperian falsificationism had failed and there has to be a “New Economic Methodology”. He specified a number of criteria for this NEM and interestingly Popperian CR meets all of them, but Hands only started to realise that late in the book when he decided that Popperian CR (as opposed to falsificationism) was a “Recent Development”.

Tentative Solution: Popper reached the economists first by way of Terrence Hutchison in  1938 and later in the 1980s by way of Lakatos and his followers, notably Mark Blaug and Spiro Latsis. So hardly anyone read Popper in the original and if they did, they read to criticise from the perspective of positivism/empiricism, or Paradigm theory, or Lakatos and his criticism of falsificationism and the “static” or “rule governed” or “unhistorical” nature of Popperism.

Hands reported that Hutchison (1938) was, for economists, “the first systematic introduction to the philosophical ideas of Karl Popper and the Logical Positivists…He drew a demarcational line in the sand; on one side was a relatively homogeneous set of activities that had earned the right to be designated “Science” and on the other side was basically everything else: metaphysics, religion, ideology, ethics, poetics, praxeology, and all the other intellectual activities, that, however interesting and passion-inspiring they might be, remain epistemically trifling”…Hutchison’s criterion for demarcating the scientific and empirically meaningful from the non-scientific and meaningless resides in the empirical testability (potentially falsifiability) of the proposition in question.” (Hands, 2001, 49-50)

That was the point of Carnap’s influential paper on testability and meaning which gave the impression that Popper’s criterion had been taken on board because it was concerned with meaning and not scientific investigation (Number One in the list of Standard Errors). While that view was widespread it was easy for Hands to think of Popper as a part of the Received View.

“I have included Karl Popper’s falsification as part of the Received View, even though, as noted above, most equate the Received View exclusively with logical empiricism” (88).

This aggregation of Popper with the positivists and logical empiricists is incomprehensible in the light of the fact that Popper never signed up to the two core elements of their program – the quest for a criterion meaning and their approach to the problem of induction.

Hands went on to say that it was surprising to philosophers when Popper’s views were taken up by economists. (Anticipating the punchline of the joke, it was not Popper’s ideas that were taken up, but a distorted and misleading representation of them).

“…there was very little inkling mid-century that Popper would end up being the dominant philosophical name in post World War II economic methodology. The fact that Popper did eventually attain such status among economists is particularly curious given that he never achieved a similar standing among his cohort group within the philosophy of natural science”.

The weird thing about Hutchison’s 1938 book is that there is not a single mention of Popper in the text, just a few rather enigmatic footnotes, including one which is a quote in German from Logik der Forschung.

“Popper” assumed a profile in the 1980s but mostly because Blaug, the prime mover in the field, was captivated by Lakatos, both in person and in his writing, and he thought that Lakatos was a Popperian, or at least 80% Popper. Someone pointed out, possibly Blaug, that the economists came to Popper AFTER their first and formative encounters with Kuhn and Lakatos (and of course the logical empiricists), so they were always looking at him from the wrong end of the telescope.

It is important to think in democraphic terms: some of us met Popper’s books in the 1960s but this generation is aproaching retirement or beyond. If you move on to the seventies when Lakatos was making his mark, the students of that decade are now in their fifties and the essential background to Popper’s work, the failure of positivism in the 1930s, is beyond their ken.  It is all about Kuhn, Lakatos, Feyarabend, US pragmatists, remnants of positivism and logical empiricism, and of course POMO coming from left field.

A theory can only be corroborated by the evidence when the negation of that evidence would falsify the theory. That is, the evidence must represent a test of the theory, and a test requires the possibility of failure. Tautologies and metaphysical hypotheses, then, are uncorroborable, since they cannot be falsified in principle.

Is Popper’s corroboration merely inductive support in disguise? No.

Consider the sunrise. My evidence of the sunrise each past morning corroborates my hypothesis that the sunrise will occur every morning, because if the sun had not risen on any of these days, then my hypothesis would be falsified. Every morning is a fresh test of my hypothesis. So far it has passed, and each further success corroborates my hypothesis a little more.

However, what about my expectation that the sun will rise tomorrow morning? Is this corroborated by evidence of sunrises in the past? That is, had the sun not risen on any previous day, would it contradict the claim that the sun will rise tomorrow morning? No. Evidence of past sunrises does not corroborate expectations of future sunrises, even though it does corroborate the general hypothesis that the sun will rise every morning.

The confusion stems from a fallacy of decomposition. That is, supposing what is true for the whole (sunrises in general) is true for its constituent parts (particular sunrises). In this case, while a theory may be highly corroborated, it does not follow that its logical consequences are also highly corroborated.

In other words, corroboration is not transmissible from premises to conclusion in a valid argument. In particular, evidence that corroborates a theory doesn’t also corroborate predictions derived from the theory. Corroboration is not ampliative; it’s more like a scorecard. That is, it’s just a measure of past performance and doesn’t entail anything about future success. Popper said this explicitly.

Working on the early reception of Popper’s ideas and the way the “Popper Legend” became established – the idea that he could be aggregated with the positivists and logical empiricists and hence ignored when their program was eventually discredited.

Starting with Hacohen’s biography and his account of the way LdF was received when it was hot off the press.

“Logik der Forschung created a stir in Vienna and beyond, wherever the circle’s network reached.  For a specialized book on scientific philosophy, it was widely read and reviewed.” [some reviews are cited]. The Austrian economists Morgenstern, Harbeler and Hayek read it very soon after publication and were favourably impressed.

Popper sent a copy to Einstein by a circuitous route, described by Hacohen. Popper was a lifelong friend of Rudlof Serkin, the pianist, who passed he book on to his mother-in-law Frida Busch, wife of the violinist Adolf Busch, who was a friend of Einstein. The book travelled with a note from Frida Busch that the young author did not have an academic position and could use any help that Einstein might offer. Einstein replied warmly, endorsing the philosophy on all the essential points, and he asked what he could do to help. Popper was advised to mention his need for a fellowship but he was too overwhelmed and he refused to impose on the great man.

“Einstein praised the book and Carnap regarded it as an outstanding achievement. Polish logicians Kotarbinski and Tarski thought it extraordinary, and young philosophers Ayer, Hempel and Nagel were in awe” [not for long it seems].

On the other hand, several circle members, Frank, Neurath, Reichenbach and Schlick were critical, “even outraged”, as were the physicists in Heisenberg’s group. Carnap was a supporter, but he wrote to Popper to complain that he had exaggerated his differences with the Circle, a  theme that persisted among Circle supporters for the rest of their lives.

Besides, Carnap later appropriated the idea of falsification (testability) and used it as a criterion of meaning, adding weight to the “Popper myth” that he was concerned with meaning, like the other positivists. Hacohen reported that Schlick, the leader of the movement, lectured Popper in private about his wilful attacks on positivism and indicating that he had irreparably damaged his relations with the circle.

Hacohen reported that the publishers, Springer, printed 860 copies, of which 60 copies were gratis copies that were sent to journals and potential reviewers.  The 13.50 RM price was equivalent to two to three days work for a schoolteacher like Popper at the time. The progressive sales figures were 200 by July 1935, 415 by October 1937 and 449 by August 1939. The publishers needed to sell 440 copies to break even and Popper received no payment. The remaining stock came to grief in an Allied bombardment late in the war. [ a little –reported war crime?}

Popper described what he called the “Popper Legend” in his reply to critics in the Schilpp volume (Library of Living Philosophers). The legend states that Popper was a positivist and (maybe even a member of the Vienna Circle) and he proposed falsification as the criterion of meaning instead of the verification principle which the positivists wanted to use to banish metaphysics from polite conversations

Of course the issue of meaning and the attempt to rule metaphysics out of court on the ground of meaninglessness was an abiding obsession of the logical positivists and then the logical empiricists. The durability of this elementary mistake is a graphic illustration of the way so many of the academic truth seekers were asleep at the wheel.

Popper cited numerous  some statements of the myth and of course there was confusion caused by Carnap’s paper on falsifiability as a criterion of meaning.  F  Ayer’s book Language Truth and Logic (1936) was probably the first statement of the myth in print. Little noticed at the time, this book took after the war and for many English-speaking people , became the bible of advanced philosophy (at a time when Bertrand Russell’s influence was on the wane). Ayer was friendly and  helpful with Popper when he went to England in 1936 but he did not clarify the true situation regarding Popper’s work even when the book was reprinted several times.

Carnap and Hempel  sponsored the myth when logical positivism morphed into logical empiricism in the US. They became the leaders of the movement and in their lifelong quest for some criterion of “cognitive meaningfulness” they never modified the impression that that Popper shared their concerns (while attempting to exaggerate the distance between them).

Alice Ambrose in the US  wrote “On the criteria of literal significance” in Critica, Revisita Hispanoamericana de Filosofia (1967), suggesting that Popper tried to circumvent the problems of the principle of verifiability with a new criterion “namely, that a statement counts as meaningful if it is in principle falsifiable”, which leads to new difficulties, such as the status of existential statements like “atoms exist”.

Lothar Krauth in Die Philosophie Carnaps (1970) wrote that Popper was perhaps the first to suggest the change from verifiability to falsifiability as the criterion of meaningfulness and Leszek Kolakowski  perpetuated the same error in Positivist Philosophy (1972, pp 209 and 216).

As did Jorgen Jorgensen in “The development of logical empiricism” in the International Encyclopedia of Unified Science  (1951).

One would have expected that perception to change when LSD appeared in English in 1959 but it was expensive , like the Logik and did not circulate widely before Kuhn’s The Structure of Scientific Revolutions appeared and became he best-known challenge to the old school in the philosophy of science.

A C Grayling, a lion of British philosophy, wrote in a recent book that a statement which is not falsifiable is “vacuous” in Popper’s scheme of things. Unreal!

On my revisiting “Realism and the Aim of Science: from the Postscript to the Logic of Scientific Discovery” (1983), written around 1951-56, it is apparent that the concept of critical preference is emphasized. In considering falsifiability and falsification in isolation one might miss this.

Popper says (p65), of course we expect the sun to rise tomorrow because it is the best theory available. “Best available theory” means in comparison with other theories.

The action of comparing theories with other theories is critical. Popper (p71) replaces the problem “How do you know? What is the reason or justification, for your assertion?” by the problem: “Why do you prefer this conjecture to competing conjectures? What is the reason for your preference?”

Corroboration reports on the survival after testing. Popper was never simplistic and proposed that one might consider:

internal consistency in comparing conclusions,

investigations of the logical forms of theories,

comparing theories with other theories to determine whether or not the theory under consideration is a scientific advance,

and empirical applications of the conclusions.

Even a simplistic assertion, that the sun will rise tomorrow, can be contrasted with an alternative, the sun will not rise tomorrow. The rising of the sun as observed by humans for thousands of years corroborates the hypothesis that the sun will always rise, in non-polar latitudes, but we do not propose that the sun will always rise just because it rose before.

The expectation that the sun will not rise is not as acceptable because

1. non-rising has failed observational testing, and

2. there are arguments that are less strong in supporting non-rising rather than rising, for now.

Feynman’s account of the procedure for looking for a scientific law:

Guess, compute the consequences of the guess, check if they agree with the evidence and if the evidence persistently refuses to agree, the guess (hypothesis) is wrong.

Science is about testing guesses.

On the basis of evidence we may be sure that we are wrong but we can never be sure that we are right.

Right on!