This review was written by Joseph Agassi and published in Philosophia, 23, 1994, 345-54.


This book offers an unusual experience. Its author, Colin Simkin, is a capable philosopher though an amateur, who has retired years ago from a successful academic career as an economist, regarding ideas of Sir Karl Popper, his old friend who is even more successful as a philosopher; one cannot fail to appreciate their vigor and intent to persevere to the very end. To the unfamiliar with Popper’s ideas, to anyone else who might benefit from a straight exposition, this book is highly recommended: it has no rival except for Popper’s own intellectual autobiography, Unended Quest. For the rest I offer some marginal critical observations.

Popper is active for six decades; his yield is stable and renown for its lucidity. This is a systematic exposition of his output in the diverse fields of research. One need not explain why one publishes
another book on a popular subject, yet Simkin does explain: Popper is misunderstood and neglected by peers. Why? Because he is not read, at least not properly: his ideas are often known only second-hand, in distorted versions. This is stated in the very opening page of this book, whose motto is the unqualified praise by the famous physicist Sir Hermann Bondi:

"there is no more to science than its method, and there is no more to its method than Popper has said."

If, despite such lavish praise and the clarity and vigor of the original exposition, Popper’s ideas are still not properly comprehended, what chance does Simkin have to ameliorate matters?

It is very common to try and try again. Missionaries seldom try to improve their techniques when they fail to convert heathens. At time, their luck improves, and in any case, they are always quick to preach to the converted. So perhaps the question is not too pressing - at lest not apropos  of having published a lovely book on the intriguing ideas of an old friend. Yet Simkin continues: Popper was not that neglected, since he was elected Fellow of the Royal Society of London and of other important academies (see also pp. 181 and 189), and since his criticism was often resented rather than ignored or misconstrued. Also, delay in recognition was in part due to the delay in publication of the English
edition of his Logik der Forschung  (1935), which appeared only decades later (as The Logic of Scientific Discovery , 1959), and his Postscript  that was in proofs for decades (p. 3).

This being the case, at least in part the fault has already been corrected. Yet Simkin wishes to set the record straight and present a comprehensive view of Popper’s contributions to diverse fields, undistracted by polemics and while drawing attention to influences on Popper. Regrettably the book has some polemics against less worthy critics and ignores the better criticism of Popper’s ideas, those
offered by admirers, disciples and former students, including J. O. Wisdom, John Watkins, Peter Munz, Paul K. Feyerabend, W. W. Bartley, Imre Lakatos, I. C. Jarvie and myself. (Bartley’s contribution to Popper’s improved restatement of Popper’s own opinions is mentioned, as well as Lakatos’s mock-criticism; Simkin ignores Bartley’s criticism and Lakatos’s profound criticism of logicism, the view which Popper had endorsed before he met Lakatos.) Regrettably, there is also
almost no reference to Popper’s antecedents. This flaw can be corrected by consulting William Berkson and John Wettersten, Learning from Error: Karl Popper’s Psychology of Learning , Open Court, LaSalle, Ill., 1984.

Popper’s predecessors are scarcely mentioned (p. 21). Relying on Popper’s autobiography Simkin observes that Oswald Külpe did not distinguish argument from judgment and that Karl Bühler (Külpe’s
disciple and Popper’s Doktorvater) who divided language to levels (see below) did not distinguish the level of argumentation from the level of description. This is bizarre: Külpe was more of an objectivist than most of his peers and predecessors; his view regarding judgment was the received notion; as to the distinction in question, all distinctions are easy to make and they are all pointless unless made for specific purposes; Bühler had no need to make Popper’s distinction. Still, Simkin’s point is significant, as it alludes to a milestone in Popper’s development of his distinctive philosophy. (John R. Wettersten, The Role of Critical Rationalism , Rodopi, Amsterdam, 1992, Chapter 8.)

The introduction ends with a brief summary of Popper’s creed in twelve theses that make this book an instant classic, and a hint that this book is (almost) authorized. I deem it authorized, despite minor
inaccuracies that would not be allowed were the book the result of a full co-authorship. So much for the Introduction; there are two parts to go, the second of which is devoted to the social sciences, plus three appendices.

Part One: General Methodology

The standard technique of systematic presentations is inadequate, as it ignores the evolution of ideas, particularly the aspect of it that relates to problems. Take Popper’s view of models; what problem does it solve? Take Popper’s view of intellectual advance as the statement of a problem, the conjecturing of a theory as a tentative solution, followed by error elimination; what problem does this view solve, what views preceded it and what error elimination opened the road to it?

Popper’s early publications should offer clues, if not also the ideas of the Würzburg School from which he came (Wettersten). There are some references here to some changes. Some are echoes of Popper’s priority claims and they are uninformative:  “.A few years after Popper’s idea of a metaphysical research programme was discussed in the London School of Economics … “.. (p. 80). “.More than ten years after Popper began to write about metaphysical research programmes, some of
his London collaborators, who had access to the proofs of his unpublished Postscript , began themselves speaking about  “.scientific research programmes “.. “. (p. 82, cp. p. 83 n. 15) (The word
“.more “. in this last quote should be replaced with  “.less “.; the date of the completion of Popper’s Postscript , p. 180, is not 1956 but 1957 or later. I find these lapses puzzling.)

The idea in question, be it Popper’s or of  “.some of his London collaborators “., is that metaphysical theories, though not testable, have truth values; at times they may be criticized, at times be rendered
testable by  “.thickening “.. This idea is to be found in Popper’s classic  “.Back to the Presocratics “. of 1957 (cp. pp. 11-2), and so there is no need for priority claims. Moreover, Simkin could find an earlier date. He tells us that  “.Popper confesses to changing his mind “. (p. 79) on the matter, but offers no detail. Popper’s 1935 Logik der Forschung  displays indifference to all metaphysical theories; it declares even its author’s realism strictly private; yet it ends by a discussion of its rejection of the very same idea of metaphysical research programmes. The majestic last chapter of Popper’s monumental
The Open Society and Its Enemies  recognizes the force of metaphysical ideas as vehicles for comprehensive views of human history, but denies them truth-values. Popper’s progress, then, was not in the discovery of the idea but his change of mind about it. what signifies is not a change but the reasoning behind it. What error elimination has occurred here? Instead of reporting Popper’s reasoning, Simkin is sidetracked by polemics with Thomas S. Kuhn and Imre Lakatos (pp. 80-3). Pity.

Simkin also discusses the change in Popper’s reasoning concerning explanation. Popper’s original view presented as explanatory any valid deduction of the statement of the explained situation from a universal statement (theory) and a statement of initial conditions. This is an error: deductions of the same form are repeatedly used both in science and in technology, yet only science claims explanatory intent. What makes a scientific deduction explanatory, I suggest, is its conformity to a given metaphysical system. This seems to accord with Popper’s assertion that his theory of causal explanation is superseded by his theory of propensities, as that theory is frankly metaphysical. But one should not confuse one specific metaphysical theory (Popper’s) with metaphysics in general. After all, statistical descriptions were allowed by determinists as explanatory only on the basis of the claim that the statistics approximates some (hardly specified) strictly causal theories.

What Popper’s idea of explanation is now I cannot say, since he has not gone over his old idea and shown that its assets are preserved by the transformation from causation to probability. The older theory required that explanations be of (allegedly) repeatable events and be independently testable by (allegedly) repeatable events. The single event with the aid of which a probability theory is tested is a sample that is (allegedly) representative, so that the process of sampling is (allegedly) repeatable. Having generalized the causal theory to the case of a propensity theory with causality as the limiting case (p. 73) should work only when the conditions stipulated earlier still obtain. There is little difficulty here, perhaps, I cannot say; it hinges on the exact wording of the idea of metaphysical research programmes and the demand (possibly rejected here, see pp. 93-4) to recognize determinism as an aspect of a legitimate programme. 

Influences are first mentioned apropos  of evolutionary epistemology (p. 85) - of Konrad Lorenz and Donald Campbell. They are not described, much less discussed; Günther Wächterhäuser’s (p. 86) and Bühler’s are (p. 87). But apropos  of no problem. Wächterhäuser says, initially the eye was a food-seeking organ of some light-consuming being. This explains the homology of the eyes of different animals (p. 85). But at least two different sorts of homologous eyes exist. Is this a programme
to explain the evolution of sensory organs from some food-seeking ones? If so, then this should be said and a comment be added as to the expected explanation of the evolution of other sense organs. The sense of touch seems to be a better candidate for the programme to attack first. Is there a suggestion as to a parallel view of hearing organs?

A problem can be sensed here, even an intriguing one: Popper has repeatedly slighted the theory that all knowledge is ability to act. This theory is known as the reduction of  “knowing that “ to
“knowing how “: one cannot reduce all informative knowledge to the mere ability to act; some knowledge is the possession of information proper. This is his theory of objective knowledge, of knowledge without the knowing subject, such as the information stored in libraries. (It is a pity that Simkin asserts that this idea is contrary to commonsense, p. 31:  “.The commonsense theory of knowledge is subjectivist “., he says. How Lockean!) Popper stresses, however, that the ability to act is knowledge of sorts: admittedly, the proficiency in riding a bicycle is knowledge of sorts; likewise, he adds, trees possess knowledge, for example, the knowledge that the search for water is performed by growing roots. (This way the subjectivist thrust of the theory of  “knowing that“ as  “knowing how “ is turned into an objectivist observation in a tour de force .)

This seems to raise the problem of continuity: is there a qualitative difference between  “knowing how“ and  “knowing that “? But I am blocked: the observed world is full of discontinuities, and it is
metaphysics that unmasks some of these as inadmissible. Popper, however, uses the theory of Bühler, of levels of language, perhaps in order to bridge over discontinuities somewhat, perhaps in order to add to Bühler’s three levels of language a fourth one: Bühler assumes that language is expressive, or expressive and signaling, or expressive and signaling and descriptive, and Popper adds now the fourth and highest level of expressive and signaling and descriptive and critical (p. 87). I am still blocked: why not also the level of artistic production that moves from the expressive sound to music proper and from graphics to painting proper, for example? This will break the hierarchy. Is emergence of needs hierarchical? A logic of emergence is needed, and there is none; even the desiderata  for a good one are wanting.

Simkin’s discussion of Popper’s views as Kant’s rendered fallibilist is very perceptive. Also his concluding remarks on the emergence of consciousness are intriguing, but, alas, they only tantalize: with no logic of emergence we are stuck.

Part Two: Social Science

Simkin’s discussion of the social sciences centers on economics. It begins with a discussion of Popper’s The Poverty of Historicism. Anyone interested in this magnificent work is advised to skip this
chapter and read instead I. C. Jarvie’s discussion of it in Paul Levinson’s In Pursuit of Truth: Essays on the Philosophy of Karl Popper on the Occasion of His Eightieth Birthday , Humanities Press,
Atlantic Heights NJ, 1982. 

The second chapter is on holistic planning. I offer here simple criticism: on page 121 we read that, according to Popper,  “The rationality of choosing the best tested theory is that it is the one which has best survived critical examination “. Now, Einstein’s theories survived critical examination better than Newton’s, yet technological preference goes the other way. Popper has a retort to this simple criticism, of course, but, all the same, he is stuck - until he would consent to make that retort public and subject it to public scrutiny. Simkin’s claim on the same page that the history of the rise and fall of the Soviet empire are  “in line with what he [Popper] foresaw and so can be regarded as corroborating it “ is a very regrettable slip. It is all too understandable, but also it reveals that even Simkin has not absorbed the spirit of disinterestedness that is so characteristic of Popper’s philosophy and is so very liberating, not to say inspiring. Popper’s philosophy is, indeed, not yet understood, but Simkin has not quite overcome the obstacle to understanding it.

Plot thickens in the next chapter, on situational logic. The rationality principle is both too weak to be testable and false (p. 124). This is double indemnity. Why is the principle so important? Because it replaces the requirement from science that it should seek universal laws. This is a break from Popperian orthodoxy. “Popper did assert that there are universal social laws, and offered some
examples. It must be said, however, that … they are rather vapid and their truth is doubtful “. Popper has misled Simkin. As the sentence just quoted suggests, Popper suggests in this context that the putative laws of science are true, unlike Newtonian mechanics, which both take as their paradigm of a scientific theory. As a social-scientific theory need not be true, why not take as an example,  “All adults are married “? Because it explains too little? Because it is not corroborated? Some important theories in the natural sciences were never corroborated, and explained little or nothing. The discussion has started on the wrong foot. What is to be explained are statements of regularities, statements of general, repeatable facts. Are there general facts in the social sciences? Popper says yes; how says Simkin?

Statements of regularities need not be true. Most factual statements of physics known to schoolchildren are refuted. There are rules about factual statements acceptable to science that are generally recognized - perhaps the only methodological rules unchallenged by practitioners ever
since they were instituted, one by Robert Boyle and one by Newton: first, only (allegedly) repeatable observations, reported by at least two independent witnesses, are recognized as facts to be explained; second, when refuted, an observation report has to be rescued by some proper qualification. So  “All adults are married “ does not qualify. Does  “There is no free meal “? I do not know, but surely if it does, and if we discover some free meals after all, we should qualify it rather than discard it; how, I do not know; it depends on the empirical grounds on which it is first endorsed and on the empirical refutation it meets later on. Similarly, it would be very nice if the standard (allegedly) empirical observation in economics (and elsewhere) qualified by ceteris paribus  clauses be completed in the various possible manners of listing the cetera , while restricting the discourse to those that are deemed observable; their complete wording can then be tested.

We live by regularities. As Popper says, even when we order a ticket for the theater we assume that our actions involve some regularities. We can try to state these; we can try to test them; if they are refuted, we can try to qualify them and then improve upon them.. This will be a very trite exercise, akin to the study of billiard balls in seventeenth-century physics. This, I suggest, will be a magnificent
beginning of an undisputable scientific study of society. (For more details see my Technology: Philosophical and Social Aspects , Kluwer, Dordrecht, 1985.)

The chapter on piecemeal planning ends with evidence that F. A. von Hayek changed his view and endorsed Popper’s advocacy of tempered interventionism. Appendix Two is devoted to a comparison of Hayek’s and Popper’s views, and there Hayek is presented as a thinker who did not object to the state economic control that does not suppress economic competition, and differences of opinions between them are minimized. As some of Popper’s disciples, notably Gerard Radnitzky and W. W. Bartley have rejected all state intervention, and on principle, the dispute cannot be closed by quoting Hayek.

In discussing individualism Simkin suggest that one of the influences on Popper, though indirect, is due to the great Austrian economist Carl Menger (p. 140). Simkin moves on to the debate with some critics from the field of economics. He then moves on to the apex, Popper’s theory of traditions and institutions and of the role of history. Though he has a slant on economics, his presentation is fairly expository. Despite its enormous significance I will not comment on it.

The last pages of this Part are devoted to economic method, which is understandable in view of the significance that many commentators in the field ascribe to Popper and on account of Simkin being an economist himself. Not being one myself, I hesitate, and merely point out that in mathematical economics all sorts of assumptions are made reasonably, and they are then applied unreasonably. Popper has not discussed the question, when is it rational to apply a mathematical theory? This is no
complaint, but a caveat . Popper has hardly studied this question, and so he has offered no specific idea that can help discussing it. Imperfect rationality, however, can be studied independently of any
assumption of classical mathematical economic theory, particularly the assumption that consumers know what they want and what they can get and at what price.

The same goes for the discussion of refutability of economics: the questions to address first are these: Does the literature offer economic general repeatable facts? If yes, they should be listed.
Popper has the backing of the whole scientific tradition when he says that only repeatable factual statements are scientific, and his explanation for this is terrific: only they can serve as potential
falsifiers: no general facts, no refutability. Perhaps Simkin alludes to this point when he observes that for a truly Popperian economics some econometrics is mandatory (p. 170): he regrets that econometricians are not Popperians (p. 171); the question is, are their results scientific (i.e., repeatable)?

The final pages go into technical details of economics. First, statistics. Simkin rightly glosses over complications (p. 173f.). He erroneously declares that explanations by fitting curve are not
universal laws, as height distributions in Japan and Australia differ (p. 174). I disagree. The observation that the Japanese are by-and-large shorter than the Australians is repeatable, and hence a putative law of nature. If one is finicky one can characterize the locations by some observed characteristics and take it from there. The observations may be refuted, but they remain scientific. Simkin moves on to regression analysis, which is very questionable in many of its applications, namely, those legitimized by the inductivism. “Notwithstanding much impressive and sophisticated work on econometric methods there are basic difficulties which limit the value of their application “ (pp. 175-6) concludes Simkin. He describes the difficulties of empirical testing; there is no need for that: the onus  is on the theory, Popper rightly observes: one should be able to  “read off “ a testable theory how it can be tested. Let me conclude by an empirical observation: every time I ask economists if there are any repeatable facts of economics, unless they say clearly, no, their replies are unclear. This is the mark of the field not being scientific (as yet) in the only sense that the word is generally received.


Appendix One is a recollection of Popper’s life in New Zealand. It is as moving as it is revealing, and it will secure this book a place in Popperiana.

Appendix Two claims that Popper and Hayek could iron out differences between their opinions by conversation (p. 197). It is strange to see Simkin ruling difference of opinion between friends as disturbing. Again, it seems to me a sign of failing to see the great liberating force of Popper’s philosophy.

Appendix Three is a brief advice to Popper’s Russian readers. It concerns the greatest need of post-Communist Russia that, according to Popper, is not merely market economy nor merely democratic institutions, since these two assets are nothing without the rule of law; it is the rapid implementation the rule of law that the Russians should consider seriously. I find this very profound and very perceptive, as recent experiences in the previous Soviet Union unfortunately exemplify. Popper
further recommend that Russia adopt, as a means of transition, some western constitution, such as the German or the French. I doubt that this is feasible, but admire the spunk, the keen perception, and the great concern for human suffering illustrated in this message.

Colin Simkin, Popper’s Views on Natural and Social Science Brill, Leiden, 1993. pp. 201
the Rathouse