Bayes’ rule shows how one might rationally change one’s beliefs in the light of evidence. It is the foundation of a statistical method called Bayesianism. In health care research, Bayesianism has its advocates but the dominant statistical method is frequentism. There are at least two important philosophical differences between these methods. First, Bayesianism takes a subjectivist view of probability (i.e. that probability scores are statements of subjective belief, not objective fact) whilst frequentism takes an objectivist view. Second, Bayesianism is explicitly (...) inductive (i.e. it shows how we may induce views about the world based on partial data from it) whereas frequentism is at least compatible with non-inductive views of scientific method, particularly the critical realism of Popper. Popper and others detail significant problems with induction. Frequentism’s apparent ability to avoid these, plus its ability to give a seemingly more scientific and objective take on probability, lies behind its philosophical appeal to health care researchers. However, there are also significant problems with frequentism, particularly its inability to assign probability scores to single events. Popper thus proposed an alternative objectivist view of probability, called propensity theory, which he allies to a theory of corroboration; but this too has significant problems, in particular, it may not successfully avoid induction. If this is so then Bayesianism might be philosophically the strongest of the statistical approaches. The article sets out a number of its philosophical and methodological attractions. Finally, it outlines a way in which critical realism and Bayesianism might work together. (shrink)

Malgré les critiques de la théorie de Karl Popper sur la falsifiabilité pour la démarcation entre la science et la non-science, principalement la pseudo-science, ce critère est toujours très utile et parfaitement valide après avoir été perfectionné par Popper et ses disciples. De plus, même dans sa version originale, qualifiée de « dogmatique » par Lakatos, Popper n’a pas affirmé que cette méthode constituait un critère absolu de démarcation : un seul contre-exemple ne suffit pas à falsifier une théorie ; (...) une théorie peut légitimement être sauvée de la falsification en introduisant une hypothèse auxiliaire. Comparé à la théorie des révolutions de Kuhn, de qui lui-même s'est dissocié pour la transformer en une théorie des « micro-révolutions », j'estime que la méthode de démarcation de Popper, ainsi que le développement ultérieur proposé par lui, incluant la corroboration et la vraisemblance, même imparfait, n’est pas seulement valable aujourd’hui, mais c’est la meilleure méthodologie de démarcation. -/- SOMMAIRE: -/- Abstract Introduction 1. Le problème de la démarcation 2. Pseudoscience 3. Falsifiabilité 4 Falsification et réfutation 5 Extension de la falsifiabilité 6. Critiques de la falsifiabilité 7 Support de la falsifiabilité 8 Tendance actuelle Conclusions Bibliographie Notes -/- DOI: 10.13140/RG.2.2.19124.60805 . (shrink)

În această lucrare argumentez faptul că, în ciuda criticilor teoriei falsificabilității propuse de Karl Popper pentru demarcarea între știință și ne-știință, în principal pseudoștiință, acest criteriu este încă foarte util, și perfect valabil după perfecționarea lui de către Popper și adepții lui. Mai mult, chiar și în versiunea sa inițială, considerată de Lakatos ca ”dogmatică”, Popper nu a afirmat că această metodologie este un criteriu absolut de demarcare: un singur contra-exemplu nu este suficient pentru a falsifica o teorie; mai mult, (...) o teorie poate fi salvată în mod legitim de falsificare prin introducerea unei ipoteze auxiliare. În comparație cu teoria lui Kuhn a revoluțiilor, de care el însuși s-a dezis ulterior transformând-o într-o teorie a ”micro-revoluțiilor”, consider că metodologia de demarcare a lui Popper, împreună cu dezvoltarea ulterioară propusă de acesta, inclusiv coroborarea și verosimilitudinea, deși imperfectă, nu numai că este valabilă și azi, dar este încă cea mai bună metodologie de demarcare. Pentru argumentare, m-am folosit de principalele lucrări ale lui Popper care tratează această problemă, și a principalilor săi critici și susținători. După o scurtă prezentare a lui Karl Popper, și o introducere în problema demarcației și metodologia falsificabilității, trec în revistă principalele critici aduse și argumentele susținătorilor săi, accentuând pe ideea că Popper nu a pus niciodată semnul egalității între falsificare și respingere. În final prezint propriile concluzii în această problemă. -/- DOI: 10.58679/TW55590. (shrink)

An explicit philosophy and meta-philosophy of positivism, empiricism and popperianism is provided. Early popperianism is argued to be essentially a form of empiricism, the deviations from empiricism are traced. In contrast, the meta-philosophy and philosophy of an evolutionary naturalistic realism is developed and it is shown how the maximal conflict of this doctrine with all forms of empiricism at the meta-philosophical level both accounts for the form of its development at the philosophical level and its defense against attack from nonrealist (...) quarters. Following an earlier article on realism of similar theme (Synthese 26 (1974), 409) this paper then further explores the ramifications of a thoroughgoing realist position. (shrink)

Some think that issues to do with scientific method are last century's stale debate; Popper was an advocate of methodology, but Kuhn, Feyerabend, and others are alleged to have brought the debate about its status to an end. The papers in this volume show that issues in methodology are still very much alive. Some of the papers reinvestigate issues in the debate over methodology, while others set out new ways in which the debate has developed in the last decade. The (...) book will be of interest to philosophers and scientists alike in the reassessment it provides of earlier debates about method and current directions of research. (shrink)

Karl Popper (1902-1994) was one of the most influential philosophers of science of the 20th century. He made significant contributions to debates concerning general scientific methodology and theory choice, the demarcation of science from non-science, the nature of probability and quantum mechanics, and the methodology of the social sciences. His work is notable for its wide influence both within the philosophy of science, within science itself, and within a broader social context. Popper’s early work attempts to solve the problem of (...) demarcation and offer a clear criterion that distinguishes scientific theories from metaphysical or mythological claims. Popper’s falsificationist methodology holds that scientific theories are characterized by entailing predictions that future observations might reveal to be false. When theories are falsified by such observations, scientists can respond by revising the theory, or by rejecting the theory in favor of a rival or by maintaining the theory as is and changing an auxiliary hypothesis. In either case, however, this process must aim at the production of new, falsifiable predictions. While Popper recognizes that scientists can and do hold onto theories in the face of failed predictions when there are no predictively superior rivals to turn to. He holds that scientific practice is characterized by its continual effort to test theories against experience and make revisions based on the outcomes of these tests. By contrast, theories that are permanently immunized from falsification by the introduction of untestable ad hoc hypotheses can no longer be classified as scientific. Among other things, Popper argues that his falsificationist proposal allows for a solution of the problem of induction, since inductive reasoning plays no role in his account of theory choice. Along with his general proposals regarding falsification and scientific methodology, Popper is notable for his work on probability and quantum mechanics and on the methodology of the social sciences. Popper defends a propensity theory of probability, according to which probabilities are interpreted as objective, mind-independent properties of experimental setups. Popper then uses this theory to provide a realist interpretation of quantum mechanics, though its applicability goes beyond this specific case. With respect to the social sciences, Popper argued against the historicist attempt to formulate universal laws covering the whole of human history and instead argued in favor of methodological individualism and situational logic. Table of Contents 1. Background 2. Falsification and the Criterion of Demarcation a. Popper on Physics and Psychoanalysis b. Auxiliary and Ad Hoc Hypotheses c. Basic Sentences and the Role of Convention d. Induction, Corroboration, and Verisimilitude 3. Criticisms of Falsificationism 4. Realism, Quantum Mechanics, and Probability 5. Methodology in the Social Sciences 6. Popper’s Legacy 7. References and Further Reading a. Primary Sources b. Secondary Sources -/- . (shrink)

Thomas Kuhn criticized falsifiability because it characterized "the entire scientific enterprise in terms that apply only to its occasional revolutionary parts," and it cannot be generalized. In Kuhn's view, a delimitation criterion must refer to the functioning of normal science. Kuhn objects to Popper's entire theory and excludes any possibility of rational reconstruction of the development of science. Imre Lakatos said that if a theory is scientific or non-scientific, it can be determined independently of the facts.He proposed a modification of (...) Popper's criterion, which he called "sophisticated (methodological) falsification". DOI: 10.13140/RG.2.2.30572.82568. (shrink)

La falsifiabilité de Popper a été critiquée à la fois pour avoir exclu la science légitime et pour avoir accordé un statut scientifique aux pseudo-sciences. Selon Larry Laudan, « cela a la conséquence fâcheuse de considérer comme « scientifique » toute demande faisant de fausses allégations de manière concluante ». Certains reprochent à Popper en disant que sa théorie ne constitue pas une alternative légitime aux propositions inductives qu’il critique. Jeffrey soutient que le bayésianisme, qui insiste sur le point de (...) savoir dans quelle mesure les preuves empiriques appuient une hypothèse, est beaucoup plus proche de la pratique scientifique que la falsifiabilité de Popper. DOI: 10.13140/RG.2.2.21235.27680. (shrink)