The basic theme of Popper's philosophy--that something can come from nothing--is related to the present situation in physical theory. Popper carries his investigation right to the center of current debate in quantum physics. He proposes an interpretation of physics--and indeed an entire cosmology--which is realist, conjectural, deductivist and objectivist, anti-positivist, and anti-instrumentalist. He stresses understanding, reminding us that our ignorance grows faster than our conjectural knowledge.

Quantum Theory and the Schism in Physics is one of the three volumes of Karl Popper’s Postscript to the Logic of scientific Discovery . The Postscript is the culmination of Popper’s work in the philosophy of physics and a new famous attack on subjectivist approaches to philosophy of science. Quantum Theory and the Schism in Physics is the third volume of the Postscript . It may be read independently, but it also forms part of Popper’s (...) interconnected argument in the Postscript . It presents Popper’s classic statement on quantum physics and offers important insights into his thinking on problems of method within science and physics as a whole. (shrink)

A brief historical comment on scientific knowledge as Socratic ignorance -- Some critical comments on the text of this book, particularly on the theory of truth Exposition [1933] -- Problem of Induction (Experience and Hypothesis) -- Two Fundamental Problems of the Theory of Knowledge -- Formulation of the Problem -- The problem of induction and the problem of demarcation -- Deductivtsm and Inductivism -- Comments on how the solutions are reached and preliminary presentation of the solutions -- Rationalism (...) and empiricism-deductivism and inductivism -- The possibility of a deductivist psychology of knowledge -- The Problem of Induction -- The infinite regression (Hume's argument) --The inductivist positions -- The Normal-Statement Positions -- The normal-statement positions: naive inductivism, strict positivism and apriorism -- Critique of strict positivism - twofold transcendence of natural laws -- The transcendental method - presentation of apriorism -- Critique of apriorism -- Kant and Fries -- Supplement to the critique of apriorism. (Psychologism and transcendentalism in Kant and Fries.-On the question of the empirical basis.) -- Probability Positions -- The probability positions - subjective belief in probability -- Statements about the objective probability of events -- Probability as an objective degree of validity of universal empirical statements -- One way of more closely defining the concept of the probability of a hypothesis (primary and secondary probability of hypotheses). The concept of simplicity -- The concept of the corroboration of a hypothesis - positivist, pragmatist and probabilistic interpretations of the concept of corroboration -- The infinite regression of probability statements -- Pseudo-Statement Positions -- The pseudo-statement positions: new formulation of the problem -- Natural laws as "instructions for the formation of statements" -- "True - false" or "useful - useless"? Consistent pragmatism --Difficulties of consistent pragmatism -- Tool and schema as purely pragmatic constructs -- Natural laws as propositional functions -- Conventionalism -- The pseudo-statement positions will temporarily be put away: conventionalism -- The three interpretations of axiomatic systems. (The circle of problems surrounding conventionalism) -- Conventionalist implicit and explicit definitions Propositional function and propositional equation -- Conventionalist propositional equations as tautological general implications -- Can axiomatic-deductive systems also be understood as consequence classes of pure propositional functions (of pseudo-statements)? -- The coordinative definitions of empiricism: synthetic general implications -- Conventionalist and empiricist interpretations, illustrated by the example of applied geometry -- Strictly Universal Statements and Singular Statements -- Implication and general implication -- General implication and the distinction between strictly universal and singular statements -- Universal concept and individual concept-class and element -- Strictly universal statements-the problem of induction and the problem of universals -- Comments on the problem of universals -- Back to the Pseudo-Statement Positions -- Return to the discussion of the pseudo-statement positions -- Symmetry or asymmetry in the evaluation of natural laws? -- The negative evaluation of universal statements. Critique of the strictly symmetrical interpretation of pseudo-statements -- An infinite regression of pseudo-statements -- An apriorist pseudo-statement position -- Interpretation of the critique up to this point; comments on the unity of theory and practice -- A last chance for the pseudo-statement positions -- Pseudo-Statement Positions and the Concept of Meaning -- The concept of meaning and logical positivism -- The concept of meaning and the demarcation problem-the fundamental thesis of inductivism -- Critique of the inductivist dogma of meaning -- Fully decidable and partially decidable empirical statements-the antinomy of the knowability of the world. (Conclusion of the critique of the pseudo-statement positions.) -- The dialectical and the transcendental corroboration of the solution -- Is the problem of induction solved? (shrink)

The essays in this volume represent an approach to human knowledge that has had a profound influence on many recent thinkers. Popper breaks with a traditional commonsense theory of knowledge that can be traced back to Aristotle. A realist and fallibilist, he argues closely and in simple language that scientific knowledge, once stated in human language, is no longer part of ourselves but a separate entity that grows through critical selection.

The way in which knowledge progresses, and especially our scientific knowledge, is by unjustified (and unjustifiable) anticipations, by guesses, by tentative solutions to our problems, by conjectures. These conjectures are controlled by criticism: that is, by attempted refutations, which include severely critical tests. They may survive these tests; but they can never be positively justified: they can neither be established as certainly true nor even as 'probable' (in the sense of the probability calculus). Criticism of our conjectures is of decisive (...) importance: by bringing out our mistakes it makes us understand the difficulties of the problems which we try to solve. This is how we become better acquainted with our problem, and able to propose more mature solutions: the very refutation of a theory - that is, of a tentative solution to our problem - is always a step forward that takes us nearer the truth. And this is how we can learn from our mistakes. As we learn from our mistakes our knowledge grows, even though we may never know - that is, know for certain. Since our knowledge can grow, there can be no reason here for despair of reason. And since we can never know for certain, the can be no authority here for any claim to authority, for conceit over our knowledge, or for smugness. The essays and lectures of which this book is composed apply this thesis to many topics, ranging from problems of the philosophy and history of the physical and social sciences to historical and political problems. (shrink)

This classic remains one of Karl Popper's most wide-ranging and popular works, notable not only for its acute insight into the way scientific knowledge grows, but also for applying those insights to politics and to history.

Realism and the Aim of Science is one of the three volumes of Karl Popper’s Postscript to the Logic of scientific Discovery. The Postscript is the culmination of Popper’s work in the philosophy of physics and a new famous attack on subjectivist approaches to philosophy of science. Realism and the Aim of Science is the first volume of the Postcript . Popper here formulates and explains his non-justificationist theory of knowledge: science aims at true explanatory theories, (...) yet it can never prove, or justify, any theory to be true, not even if is a true theory. Science must continue to question and criticise all its theories, even those that happen to be true. Realism and the Aim of Science presents Popper’s mature statement on scientific knowledge and offers important insights into his thinking on problems of method within science. (shrink)

Popper formulates and explains his non-justificationist theory of knowledge. Science--empirical science--aims at true explanatory theories, yet it can never prove, finally establish, or justify any of its theories as true, not even if it is in fact a true theory. Science must continue to question and criticize all its theories, even those which happen to be true.

The rational understanding of the quantum theory achieved by de Broglie is contrasted with the Copenhagen emphasis on “the quantum postulate with its inherent ‘irrationality’” (Niels Bohr, Ref. 1).

Bertrand Russell described this study, with its companion volume on Hegel and Marx, as 'a work of first-class importance which ought to be widely read for its masterly criticism of the enemies of democracy, ancient and modern. His (Popper's) attack on Plato, while unorthodox, is in my opinion thoroughly justified. His analysis of Hegel is deadly. Marx is dissected with equal acumen, and given his due share of responsibility for modern misfortunes. The book is a vigorous and profound defence (...) of democracy, timely, very interesting, and very well written'. 'A powerful and important book. It is a criticism of a set of dogmas which underlie the most influential political theories, and in consequence powerfully affect the actual conduct of human affairs. Dr Popper writes with extreme clarity and vigour. His studies in Greek history and Greek thought have obviously been profound and original. Platonic exegesis will never be the same again. Nor, I think, will Marxist exegesis. Readers should not miss studying the notes collected at the end of the two volumes.' - Gilbert Ryle, Mind. (shrink)

The way in which knowledge progresses, and especially our scientific knowledge, is by unjustified anticipations, by guesses, by tentative solutions to our problems, by conjectures. These conjectures are controlled by criticism: that is, by attempted refutations, which include severely critical tests. They may survive these tests; but they can never be positively justified: they can neither be established as certainly true nor even as 'probable'. Criticism of our conjectures is of decisive importance: by bringing out our mistakes it makes us (...) understand the difficulties of the problems which we try to solve. This is how we become better acquainted with our problem, and able to propose more mature solutions: the very refutation of a theory - that is, of a tentative solution to our problem - is always a step forward that takes us nearer the truth. And this is how we can learn from our mistakes. As we learn from our mistakes our knowledge grows, even though we may never know - that is, know for certain. Since our knowledge can grow, there can be no reason here for despair of reason. And since we can never know for certain, the can be no authority here for any claim to authority, for conceit over our knowledge, or for smugness. The essays and lectures of which this book is composed apply this thesis to many topics, ranging from problems of the philosophy and history of the physical and social sciences to historical and political problems. (shrink)

In this paper Popper formulates and discusses a new aspect of the theory of mind. This theory is partly based on his earlier developed interactionistic theory. It takes as its point of departure the observation that mind and physical forces have several properties in common, at least the following six: both are located, unextended, incorporeal, capable of acting on bodies, dependent upon body, capable of being influenced by bodies. Other properties such as intensity and extension in (...) time may be added. It is argued that a fuller understanding of the nature of forces is essential for the analysis of the mind-brain problem. The relative autonomy and indeterministic nature of mind is stressed. Indeterminism is treated in relation to a theorem of Hadamard. The computer theory of mind and the Turing test are criticized. Finally the evolution of mind is discussed. (shrink)

_'Never before has there been so many and such dreadful weapons in so many irresponsible hands.'__ - Karl Popper, from the Preface_ _All Life is Problem Solving_ is a stimulating and provocative selection of Popper's writings on his main preoccupations during the last twenty-five years of his life. This collection illuminates Popper's process of working out key formulations in his theory of science, and indicates his view of the state of the world at the end of (...) the Cold War and after the collapse of communism. (shrink)

We express here the statement » The probability of a given b equals r « symbolically by » p = r «. A formal axiomatic calculus can be constructed comprising all the well‐known laws of probability theory. This calculus can be interpreted in various ways. The present paper is a criticism of the subjective interpretation; that is to say, of any interpretation which assumes that probability expresses degrees of incomplete knowledge: a is the statement incompletely known, b is our (...) total knowledge, and p is the degree to which a is entailed by b. The subjective interpretation has often been proposed as an explanation and even a sharpening of the various objective theories . It is shown in the paper that this proposal cannot be realised because the subjective theory cannot lead to results which are compatible with the objective theory. This is due to various reasons, the most important of which is that the objective theory interprets » b « in » p « as a statement of the objective conditions of an experiment and » a « as one of its possible results. The subjective theory on the other hand interprets » b « as our total relevant knowledge which will in general include some knowledge of previous results of the experiment. It is shown that this must lead to incompatibility owing to the fact that this knowledge of previous results must influence the value of the probability.It is shown, in this way, that any probabilistic theory of the process of learning from experience—that is to say, any probabilistic theory of induction—must lead to contradictions.RésuméL'énoncé: » La probabilité de a, si b est donné, est égale à r « est ici exprimé symboliquement par » p = r «. On peut construire un système axiomatique formel qui contient toutes les règles bien connues du calcul des probabilités. Ce calcul formel peut ětre interprété de manières très différentes. L'article contient une critique des interprétations subjectives, c'est‐à‐dire des interprétations qui admettent que la probabilité exprime des degrés de connaissance incomplète: a est un énoncé qu'on ne connaǐt que partiellement, b est notre connaissance totale, et p exprime le degré auquel a est implicitement contenu dans b. L'interprétation subjective a souvent été proposée comme une explication et un renforcement des différentes théories objectives . Dans cet article, l'auteur montre que ce projet n'est pas réalisable, car la théorie subjective mène à des résultats qui contredisent la théorie objective. Plusieurs circonstances sont responsables de cette situation; la plus importante, c'est que la théorie interprète le » b « dans » p « comme une description des conditions objectives d'une expérience . D'autre part, la théorie subjective interprète » b « comme notre savoir total , et ce savoir inclura en général des informations sur les résultats obtenus antérieurement pour cette expérience. L'auteur montre que ce fait conduit à une contradiction entre les deux interprétations, car cette connaissance doit avoir une influence sur la valeur subjective de la probabilité.A l'aide de ce raisonnement, on peut montrer que la théorie des probabilités appliquée au processus inductif tirant une expérience du domaine expérimental conduit à des contradictions.ZusammenfassungDie Aussage » Die Wahrscheinlichkeit von a, wenn b gegeben ist, ist gleich r « wird hier symbolisch durch » p = r « ausgedrückt. Ein formales Axiomensystem kann konstruiert werden, das alle die wohlbekannten Regeln der Wahrscheinlichkeitsrechnung enthält. Dieser formale Kalkül kann in sehr verschiedener Weise interpretiert werden. Der Artikel enthält eine Kritik der subjektiven Interpretationen; das heisst, jener Interpretationen die annehmen, dass die Wahrscheinlichkeit Grade von unvollständigem Wissen ausdrückt: a ist ein Satz der unvollständig gewusst wird, b ist unser Gesamtwissen, und p drückt den Grad aus zu dem a in b implizit enthalten ist. Die subjektive Interpretation wurde oft als eine Erklärung und Verschärfung der verschiedenen objektiven Theorien vorgeschlagen. In dem Artikel wird gezeigt, dass der Vorschlag undurchführbar ist, da die subjektive Theorie zu Resultaten führt, die der objektiven Theorie widersprechen. Verschiedene Umstände tragen zu dieser Situation bei. Der wichtigste dieser Umstände ist, dass die objektive Theorie das » b « in » p « als eine Beschreibung der objektiven Bedingungen eines Experimentes interpretiert . Andererseits interpretiert die subjektive Theorie » b « als unser Gesamtwissen , und dieses wird im allgemeinen Informationen bezüglich früherer Resultate dieses Experiments einschliessen. Es wird gezeigt, dass das zu einem Widerspruch zwischen den Interpretationen führt, da dieses Wissen Einfluss auf den subjektiven Wahrscheinlichkeitswert haben muss.Mit Hilfe dieses Gedankenganges wird gezeigt, dass die Wahrscheinlichkeitstheorie des induktiven Lernens aus der Erfahrung zu Widersprüchen führt. (shrink)

One of the most influential thinkers of the 20th century, Sir Karl Popper here examines the problems connected with human freedom, creativity, rationality and the relationship between human beings and their actions. In this illuminating series of papers, Popper suggests a theory of mind-body interaction that relates to evolutionary emergence, human language and what he calls "the three worlds." Rene; Descartes first posited the existence of two worlds--the world of physical bodies and the world of mental states. (...) Popper argues for the existence of "world 3" which comprises the products of our human minds. He examines the interaction between mental states--hopes, needs, plans, ideologies or hypotheses--and the physical states of our brain. Popper forcefully argues against the materialism forwarded by many philosophers which denies the existence of mental states. Instead, he demonstrates that the problem of the interaction between mental and physical states remains unresolved. Knowledge and the Body-Mind Problem is based on Popper's never-before published lectures at Emory University in 1969. Popper has extensively revised the lectures but has retained their accessible format. He has also incorporated some of the discussions which followed the lectures, providing an engaging exchange between the philosopher and his audience. (shrink)

The objective of this study is to explore factors that affect the decisions single-child parents make when considering whether to have a second child applying the psychological theory of planned behaviour. Quantitative survey data from a sample of parents with a single child selected from a Slovak representative sample was used to perform regression analysis assessing effects of attitudes, subjective norms and perceived control on intention to have a second child within the next three years. Results largely confirm the (...) model captured in TPB. All three components of the TPB have a significant effect on intentions to have a second child. A particular set of liberal and conservative attitudes facilitate plans to have a second child. The strongest predictors, however, are the perceived pressure from the social environment and subjective desire to have a child. The study concludes that, along with demographic and sociological variables, psychological factors play a significant role in decision-making processes concerning reproductive planning. (shrink)

Many writers, both scientists and philosophers, when discussing the mind‐body problem, adopt what might be called the physicalist principle of the closedness of the physical world. They reject the possibility that the physical world is causally open to a realm of conscious experience that is not part of it.Among the upholders of such a view are those who may be called radical materialists or radical physicalists, who deny that there exists a realm of conscious experience. Also, there are the proponents (...) of various identity theories, who admit that there is such a realm, but claim that it may be in some sense identified with parts of the physical world.There are, however, other writers who accept the physicalist principle, but who nevertheless also accept that there exists a genuinely autonomous realm of conscious experience. Such writers often hold some form of panpsychism or epiphenomenalism, and in what follows these two views are briefly explained and critically discussed. (shrink)

“There could be no fairer destiny for any. . . theory than that it should point the way to a more comprehensive theory in which it lives on, as a limiting case.” ALBERT EINSTEIN..

Two questions are addressed in this article: 1. Why are people attracted to leaders? 2. How are leaders' images construed? The first question is analyzed by using the concept of “deity” as a frame of reference for an “ideal model” of leadership. God as a “screen of projections” can satisfy the believer's fundamental needs and desires, as well as serving as a reference for causal attributions and a provider of transcendental meaning. Using Construal Level Theory, deity, as a frame (...) of reference, also facilitates analysis of the second question. This analysis explains universal principles underlying the leadership construal, and the psychological principles and culture-bound processes relevant to construing different images of leadership in different collectives. (shrink)

The relation between body and mind is one of the oldest riddles that has puzzled mankind. That material and mental events may interact is accepted even by the law: our mental capacity to concentrate on the task can be seriously reduced by drugs. Physical and chemical processes may act upon the mind; and when we are writing a difficult letter, our mind acts upon our body and, through a chain of physical events, upon the mind of the recipient of the (...) letter. This is what the authors of this book call the 'interaction of mental and physical events'. We know very little about this interaction; and according to recent philosophical fashions this is explained by the alleged fact that we have brains but no thoughts. The authors of this book stress that they cannot solve the body mind problem; but they hope that they have been able to shed new light on it. Eccles especially with his theory that the brain is a detector and amplifier; a theory that has given rise to important new developments, including new and exciting experiments; and Popper with his highly controversial theory of 'World 3'. They show that certain fashionable solutions which have been offered fail to understand the seriousness of the problems of the emergence of life, or consciousness and of the creativity of our minds. In Part I, Popper discusses the philosophical issue between dualist or even pluralist interaction on the one side, and materialism and parallelism on the other. There is also a historical review of these issues. In Part II, Eccles examines the mind from the neurological standpoint: the structure of the brain and its functional performance under normal as well as abnormal circumstances. The result is a radical and intriguing hypothesis on the interaction between mental events and detailed neurological occurrences in the cerebral cortex. Part III, based on twelve recorded conversations, reflects the exciting exchange between the authors as they attempt to come to terms with their opinions. (shrink)

In a paper ‘Is it True What They Say About Tarski?’, Dr Susan Haack explicitly denies the truth of an implicit assertion of mine, by writing ‘… Tarski does not present his theory as a correspondence theory’. My reply is to quote two brief passages from Tarski's work.

"Bartley and Radnitzky have done the philosophy of knowledge a tremendous service. Scholars now have a superb and up-to-date presentation of the fundamental ideas of evolutionary epistemology." --Philosophical Books.

The article reviews the various ramifications in the discussion on leadership, focusing on the view of leadership as relationships between leaders and followers. Three main types of leader-follower relations are discussed, and their specific characteristics are described: regressive relations, symbolic relations, and developmental relations. After analyzing the major implications, as well as the conceptual limitations, of these perspectives, the article suggests directions for a more integrative conceptualization of leader-follower relations.

This study, theoretically based on integrated threat and image theory, explored (1) the mental constructs produced by the Slovak majority in relation to cooperation with the Roma minority and (2) differences in thinking about different Roma demographic groups. In Slovakia, prejudice towards Roma people is a long-standing phenomenon. In this study there were 228 participants, mostly young adults, who produced 22 categories of associations, explored using content and network analyses. The frequency of category associations in the first and second (...) research group was mostly the same, but the distribution differed for the demographic groups considered by the third research group, which was asked to produce associations separately for each Roma demographic group. The largest difference measured was between integrated and segregated Roma people – the associations were mostly positive for the first and negative for the second. These results provide the first empirical exploration of cooperation intentions with Roma people in the Slovak context and suggestions are made for future discourse on Roma. (shrink)

Karl Popper argued in 1974 that evolutionary theory contains no testable laws and is therefore a metaphysical research program. Four years later, he said that he had changed his mind. Here we seek to understand Popper’s initial position and his subsequent retraction. We argue, contrary to Popper’s own assessment, that he did not change his mind at all about the substance of his original claim. We also explore how Popper’s views have ramifications for contemporary discussion (...) of the nature of laws and the structure of evolutionary theory. (shrink)

Conpiracy theories are widely deemed to be superstitious. Yet history appears to be littered with conspiracies successful and otherwise. (For this reason, "cock-up" theories cannot in general replace conspiracy theories, since in many cases the cock-ups are simply failed conspiracies.) Why then is it silly to suppose that historical events are sometimes due to conspiracy? The only argument available to this author is drawn from the work of the late Sir Karl Popper, who criticizes what he calls "the conspiracy (...) theory of society" in The Open Society and elsewhere. His critique of the conspiracy theory is indeed sound, but it is a theory no sane person maintains. Moreover, its falsehood is compatible with the prevalence of conspiracies. Nor do his arguments create any presumption against conspiracy theories of this or that. Thus the belief that it is superstitious to posit conspiracies is itself a superstition. The article concludes with some speculations as to why this superstition is so widely believed. (shrink)

Karl Popper developed a theory of deductive logic in the late 1940s. In his approach, logic is a metalinguistic theory of deducibility relations that are based on certain purely structural rules. Logical constants are then characterized in terms of deducibility relations. Characterizations of this kind are also called inferential definitions by Popper. In this paper, we expound his theory and elaborate some of his ideas and results that in some cases were only sketched by him. (...) Our focus is on Popper's notion of duality, his theory of modalities, and his treatment of different kinds of negation. This allows us to show how his works on logic anticipate some later developments and discussions in philosophical logic, pertaining to trivializing connectives, the duality of logical constants, dual-intuitionistic logic, the conservativeness of language extensions, the existence of a bi-intuitionistic logic, the non-logicality of minimal negation, and to the problem of logicality in general. (shrink)

This paper deals with Popper's little-known work on deductive logic, published between 1947 and 1949. According to his theory of deductive inference, the meaning of logical signs is determined by certain rules derived from ?inferential definitions? of those signs. Although strong arguments have been presented against Popper's claims (e.g. by Curry, Kleene, Lejewski and McKinsey), his theory can be reconstructed when it is viewed primarily as an attempt to demarcate logical from non-logical constants rather than as (...) a semantic foundation for logic. A criterion of logicality is obtained which is based on conjunction, implication and universal quantification as fundamental logical operations. (shrink)

Karl Popper’s philosophy of science provides a foundation for a theory of literary interpretation that avoids the pitfalls of contemporary theories. This study outlines the approach and applies it to challenging works from the Gospel of Mark to Patrick Modiano.

Science seems to develop by inducing new knowledge from observation. However, it is hard to find a rational justification for induction. Popper offers one attempt to resolve this problem. Nursing theorists have tended to ignore or reject Popper, often on the false belief that he is a logical positivist (and hence hostile to qualitative research). Logical positivism claims that meaningful sentences containing any empirical content should ultimately be reducible to simple, observation statements. Popper refutes positivism by showing (...) that there are no such simple statements. He is not a positivist. For Popper, the scientist begins with problems and puts forward trial solutions. These are subjected to rigorous testing aimed at falsifying them. A new theoretical position is then reached in which the scientist knows either that the trial solutions are false or that they have not yet been falsified. Science is characterized by the fact that it tests its ideas through attempted falsification. Nonscience tests its ideas through attempted refutation. Nursing theory is a mixture of science and non-science. Popper’s method requires rigorous testing of theory in both realms. As such, some nursing theory should be discarded. Popper’s view faces at least two important criticisms. One is that a scientist can always reject an apparent falsification by instead altering some auxiliary hypothesis (e.g. denying the accuracy of the falsifying observation). Popper can deal with this argument by saying that defence of a theory in this way will eventually break down if the theory is false. The second criticism is that Popper’s method does ultimately draw upon induction. This criticism is true, but his method can be usefully adapted. An adapted from of Popper’s philosophy of science provides a good basis for nursing theory. (shrink)

Mit "propensity" meint Popper die Neigung oder Tendenz einer Versuchsanordnung ein bestimmtes Versuchsergebnis zu produzieren. Sie wird durch die Wahrscheinlichkeit des Ergebnisses gemessen oder ist sogar mit ihr identisch. Zunächst hatte er behauptet, jeder Wahrscheinlichkeitskalkül lasse sich als Axiomatisierung sowohl der Theorie subjektiver Wahrscheinlichkeiten als auch der propensity-Theorie der Wahrscheinlichkeit interpretieren. Ohne diese Position ausdrücklich aufzugeben hat er nun einen Kalkül vorgelegt, der die einzig adäquate Axiomatisierung der propensity-Theorie darstellen soll. Seine Postulate widersprechen aber nicht nur allen herkömmlichen Wahrscheinlichkeitskalkülen. (...) Da die meisten seiner Axiome gleichzeitig für die logische Wahrscheinlichkeit von Sätzen gelten sollen und da er ausdrücklich bestimmte Zusammenhänge zwischen logischer Wahrscheinlichkeit und propensity postuliert, ist seine Axiomatisierung auch inkonsistent, zumal selbst seine Axiome für die logische Wahrscheinlichkeit mit den herkömmlichen Kalkülen logischer Wahrscheinlichkeit nicht vereinbar sind. (shrink)

Popper's theory of the attraction of closed societies conflicts with his theory of research: the former sees rational thought as contrary to man's nature, whereas the latter sees it as an innate psychological process. This conflict arose because Popper developed a theory of the movement from the closed society—Heimat—to civilized society, which sees civilized society as a burden, before he adapted Selz's view of directed thought processes as problem solving, which sees rationality as natural. Rejecting (...) the earlier view and retaining the latter one opens up possibilities for better explanations of closed societies and better means of combating them. Key Words: closed society • Popper • Selz • problems • institutions. (shrink)

A fundamental tenet of Paul Feyerabend’s pluralistic view of science has it that theory proliferation, that is, the availability of theoretical alternatives, is of crucial importance for the detection of anomalies in established theories. Paul Hoyningen-Huene calls this the Anomaly Importation Thesis, according to which anomalies are imported, as it were, into well-established theories from competing alternatives. This article pursues two major objectives: (a) to work out the systematic details of Feyerabend’s ideas on theory proliferation and anomaly import (...) as they are presented in his early publications and his Against Method and (b) to compare Feyerabend’s ideas on theory proliferation and anomaly import with corresponding features in Popper’s critical rationalist philosophy of science. As it turns out, neither the Principle of Proliferation nor the Anomaly Importation Thesis are necessarily incompatible with critical rationalism. In spite of Feyerabend’s general anti-Popperian attitude, I argue that theoretical pluralism can be seen as an advancement of the critical rationalist philosophy and that critical rationalism provides good arguments for pluralism. (shrink)

While developing his theory of world 3, Popper rejects two claims made by Plato: first, that the inhabitants of world 3, ideas, are a source of ultimate explanation, a divine revelation of truth, and second, that these ideas are unchanging. I will rehabilitate the second claim. Man does not construct world 3 by creating his theories, nor is it a source of ultimate truth. Instead, world 3 is discovered by man, and it destroys some of his theories: destructive (...) Platonism. I discuss the impact of the modified position on the Grundlagenstreit in mathematics, taking into account Gillies’s constructive Aristotelianism. I then turn to the philosophy of computers and discuss how destructive Platonism relates to computers and the Internet. In particular, I criticize Popper’s claim that computers are nothing but elaborate pens as too pessimistic and incautious, and the fashionable “singularity” theory as too optimistic and at the same time too fatalistic. In my closing remarks, as an antidote against both views, I provide a more modest and reasonable speculation about the ultimate goal and meaning of life. (shrink)

Popper wrote extensively on the quantum theory. In Logic der Forschung he devoted a whole chapter to the topic, while the whole of Volume 3 of the Postscript to the Logic of Scientific Discovery is devoted to the quantum theory. This volume entitled Quantum Theory and the Schism in Physics incorporated a famous earlier essay, ‘Quantum Mechanics without “the Observer”’ . In addition Popper's development of the propensity interpretation of probability was much influenced by his (...) views on the role of probability in quantum theory, and he also wrote an insightful critique of the 1936 paper of Birkhoff and von Neumann on nondistributive quantum logic. (shrink)

We compare Karl Popper’s ideas concerning the falsifiability of a theory with similar notions from the part of statistical learning theory known as VC-theory . Popper’s notion of the dimension of a theory is contrasted with the apparently very similar VC-dimension. Having located some divergences, we discuss how best to view Popper’s work from the perspective of statistical learning theory, either as a precursor or as aiming to capture a different learning activity.