La réfutabilité de Karl Popper (1902-1994) définit à la fois la norme de la connaissance scientifique et se présente comme le critère du caractère empirique de toute théorie scientifique. La thèse rend compte de l’ambigüité d’une épistémologie qui s’ancre dans la logique potentielle tout en prétendant à l’effectivité pratique. Il est impossible avec un tel critère de statuer sur la scientificité de disciplines aussi diverses que le marxisme, la psychanalyse, la théorie de l’évolution, l’astrologie, étudiées par Popper et exclues du domaine des sciences pour absence de prédictibilité. La thèse met aussi en évidence que, bien que très influente en biologie, l’épistémologie normative de Popper n’a jamais été vraiment appliquée, même par ses épigones tel Jacques Monod, et n’est pas applicable. Les raisons de ces échecs doivent être recherchées non seulement dans la logique potentielle, mais aussi dans le modèle déductif-nomologique, au fondement du critère et qui deviendra la norme de toute science empirique. Si le modèle D-N d’explication, formalisé plus tard par Carl Hempel, peut servir à la construction du modus operandi de la réfutation en physique, il ne peut prétendre à l’opérabilité dans les disciplines où l’existence de lois demeure problématique et la notion de prédiction plurielle comme en biologie. Enfin la thèse, s’appuyant sur l’analyse critique de l’épistémologie poppérienne, propose une typologie des prédictions, précise la spécificité des énoncés biologiques et envisage un autre critère de scientificité qui prenne davantage en compte la science en action. / Karl Popper's falsifiability (1902-1994) defines at the same time the standard of scientific knowledge, and is presented in the form of a criterion of the empirical character of any scientific theory. The thesis reflects the ambiguity of an epistemology that is grounded in potential logic while aiming practical effectivity. It is impossible with such a criterion to rule on the scientificity of disciplines as diverse as Marxism, psychoanalysis, the theory of the evolution, astrology, studied by Popper and excluded from the field of sciences for lack of predictability. The thesis also highlights that, although very influential in biology, Popper’s normative epistemology has never really been applied, even by his followers like Jacques Monod, and is not applicable. The reasons for these failures must be investigated not only in potential logic, but also in the deductive-nomological model, the basis of the criterion, and which will become the norm in empirical science. If D-N model of explanation, formalized later by Carl Hempel, can be used for the construction of the modus operandi of the falsification in physics, it cannot be applied in the disciplines where the existence of laws remains problematic and where the concept of prediction is plural, live in biology. Finally the thesis, based on a critical analysis of Popper’s epistemology, proposes a typology of predictions, specifies biological statements and tries to look at another criterion of scientificity that takes greater account of science in action.

Theory is vital for our scientific understanding of the social world. Building, developing, and evaluating theory are therefore central practices within the social sciences. This study performs an evaluation of rational choice theory within the field of political participation. This is a theoretical framework that has had significant problems reconciling theoretical prediction with empirical findings, causing what is called the paradox of participation. For more than sixty years rational choice theorists have tried to develop new formulations of the theory to avoid this paradox. The purpose of this study is to forward this debate by providing a new perspective on rational choice theory that is purely theoretical. Using the evaluative criteria of falsifiability and leverage, the study finds that a theory using both collective and selective incentives, while also allowing the formulation of the theory to change depending on the form of political participation one wants to explain provides the most promising approach. However, the evaluation does reveal some issues in connection to selective incentives. A potential alternative solution to the paradox is therefore briefly discussed, yet a more thorough exploration of this venue is left to future research.

This thesis seeks to examine the Concept of Right Action in Karl Popper's social and moral philosophy. This is attempted through the study of his theory of rationality. Through the examination of his theory of 'critical rationalism', it has been established that a right action is a rational action, that is, an action based on a critical assessment of its possible consequences. His theory of falsifiability, which is fundamental to his theory of critical rationalization and which advocates that falsification as opposed to verification, is a true test of a theory, is also examined, in order to see whether and how it can be applied to social and moral problems. In this context it has been established that in social and political realms also, one works through theories, ideas and hypotheses which can be tested. This method is considered to be a rational and scientific method and is advocated as an alternative to authoritarian and totalitarian methods. In order to determine the viability of K. Popper's proposals, his critique of historicism is also examined. Through the study of these critiques, it has been established that historicist modes of thought and action tend to lead to totalitarian and authoritarian political and social systems, and the consequent violence. A system based on critical rationalism is considered to be the only alternative. In examining these critiques we also raised the question whether religion and tradition have any place in Popper's system. It has been shown that the critical understanding and use of tradition is fundamental and necessary. We have also shown that Popper is not anti-religion and that religion and rationality are not incompatible, when we consider that religion is not merely a metaphysical system but also a social system, i.e., a body of ethics and a way of life. A rational and a secular attitude and a religious attitude are not mutually exclusive. / Thesis / Master of Arts (MA)

This study aims to threat the problem of the scientific progress in Karl R. Popper and Thomas S. Kuhn. The scientific progress, before these two authors was taken as cumulative, so, science would grow on the way that it would incorporate new truths to the amount of truths which already was familiar. However, it was from David Hume that this form of progress was called into question, as he noticed that science rested on invalid inductive inferences, and what was thought to be truth in science was actually invalid because the premises of a inductive argument, though true, did not ensure the truth transmitted to the conclusion, once this last one said much more than what was said on the premises. This issue raised by Hume beyond having affected the scientific method, also implied the irrationality of science. It was in order to resolve this issue that the Vienna Circle proposed probability as a way to avoid both problems coming from the inductive method, as to ensure the rational character of science, although still keeping progress as cumulative. Karl R Popper was one of the first to propose a form of progress that was not positive and cumulative, in other words, the goal of science was no longer the check, nor a high probability, but the falsification of theories. Science for Popper, aims the progress and this factor is an essential part which guarantees him the rational and empirical character of scientific theories. While distortion occurred constantly and repeated overthrow of theories we would be progressing, even on a negative way. In order to solve the prior problems, Popper rejects the induction and propose hipotetic-deductive method of proof instead. On the other hand, Thomas Kuhn intended to explain the progress as non-cumulative and rational, because for this philosopher science progresses through scientific revolutions and the successive exchange of paradigms. These revolutions, on the other hand, does not occur by the means that the traditional logic can capture. As a result, this paper intends to argue in favor of Karl R. Popper, trying to demonstrate, on the field of Popper's thought that the philosophy of science Kuhn is not a position that is away from allegedly trying to combat, namely the Circle of Vienna, and while maintaining the discontinuous progress, its main way of demarcating science, that is, paradigms, is still cumulative. We conclude this study observing that the critical method proposed by Popper, although not without its problems, is a more viable alternative to the progress seen as breaking theories than the model of Kuhn, especially by rewarding the scientist more by imagination and daring to do bold conjecture than by blind obedience to a paradigm. / O presente trabalho tem por objetivo analisar o problema do progresso científico em Karl R Popper e Thomas S Kuhn. O progresso cientifico, antes desses dois autores, era tido como cumulativo, ou seja, a ciência cresceria na medida em que incorporasse novas verdades ao corpo de verdades que já lhe era familiar. No entanto, foi a partir de David Hume que essa forma de progresso foi posta em causa, pois ele observou que a ciência repousava em inferências indutivas inválidas, e aquilo que se arrogava verdade em ciência era, na verdade, inválido, pois as premissas de um argumento indutivo, embora verdadeiras, não asseguravam a verdade transmitida para a conclusão, uma vez que esta última dizia muito mais do que o que era dito nas premissas. Esse problema levantado por David Hume, além de ter afetado o método científico, também implicava na irracionalidade da ciência. Foi com o intuito de resolver esse problema que o Círculo de Viena propôs a probabilidade como uma maneira de evitar tanto os problemas oriundos da indução, como garantir o caráter racional da ciência, embora ainda mantivesse o progresso como cumulativo. Karl R Popper foi um dos primeiros a propor uma forma de progresso que não fosse positivo e cumulativo, isto é, o objetivo da ciência não mais era a verificação, e tampouco a alta probabilidade, senão o falseamento das teorias. A ciência, para Popper, tem sede de progresso e este fator é uma parte essencial que lhe garante o caráter racional e empírico das teorias científicas. Conquanto ocorresse constante falseamento e a repetida derrubada de teorias estaríamos progredindo, ainda que de maneira negativa. Com vistas a solucionar os problemas anteriores, Popper rejeitou a indução e propôs o método hipotético-dedutivo de prova em seu lugar. Por outro lado, Thomas Kuhn também pretendeu explicar o progresso como não cumulativo e racional, pois para este filósofo a ciência progride através de revoluções científicas e pela sucessiva troca de paradigmas. Estas revoluções, por sua vez, não ocorrem por meios que a lógica tradicional possa capturar. Em vista disso, esse trabalho pretende argumentar em favor de Karl R. Popper, tentando demonstrar, na esteira do pensamento popperiano que a filosofia da ciência de Kuhn não é uma posição que se afastou do que pretensamente tentava combater, a saber, o positivismo lógico, e que embora mantenha o progresso descontínuo, sua principal maneira de demarcar a ciência, isto é, por paradigmas, ainda é cumulativa. Concluímos este trabalho observando que o método crítico proposto por Popper, embora não isento de problemas, é uma alternativa mais viável para o progresso entendido como ruptura de teorias do que o modelo de Kuhn, sobretudo por premiar o cientista mais pela imaginação e ousadia ao fazer conjecturas audaciosas do que pela obediência cega a um paradigma.

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