Valeriano Iranzo

There are different Bayesian measures to calculate the degree of confirmation of a hypothesis H in respect of a particular piece of evidence E. Zalabardo (Analysis 69:630–635, 2009) is a recent attempt to defend the likelihood-ratio measure (LR) against the probability-ratio measure (PR). The main disagreement between LR and PR concerns their sensitivity to prior probabilities. Zalabardo invokes intuitive plausibility as the appropriate criterion for choosing between them. Furthermore, he claims that it favours the ordering of pairs evidence/hypothesis generated by LR. We will argue, however, that the intuitive non-numerical example provided by Zalabardo does not show that prior probabilities do not affect the degree of confirmation. On account of this, we conclude that there is no compelling reason to endorse LR qua measure of degree of confirmation. On the other side, we should not forget some technicalities which still benefit PR

Extrapolation of causal claims from study populations to other populations of interest is a problematic issue. The standard approach in experimental research, which prioritises randomized controlled trials and statistical evidence, is not devoid of difficulties. Granted that, it has been defended that evidence of mechanisms is indispensable for causal extrapolation. We argue, contrarily, that this sort of evidence is not indispensable. Nonetheless, we also think that occasionally it may be helpful. In order to clarify its relevance, we introduce a distinction between a positive and a negative role of evidence of mechanisms. Our conclusion is that the former is highly questionable, but the latter may be a trustworthy resource for causal extrapolation.

Epidemiological models have played a central role in the COVID-19 pandemic, particularly when urgent decisions were required and available evidence was sparse. They have been used to predict the evolution of the disease and to inform policy-making. In this paper, we address two kinds of epidemiological models widely used in the pandemic, namely, compartmental models and agent-based models. After describing their essentials—some real examples are invoked—we discuss their main strengths and weaknesses. Then, on the basis of this analysis, we make a comparison between their respective merits concerning three different goals: prediction, explanation, and intervention. We argue that there are general considerations which could favour any of those sorts of models for obtaining the aforementioned goals. We conclude, however, that preference for particular models must be grounded case-by-case since additional contextual factors, as the peculiarities of the target population and the aims and expectations of policy-makers, cannot be overlooked.

El Positivismo Lógico a menudo ha sido presentado como una corriente filosófica monolítica obviando las profundas disensiones que hubo en su seno. El presente artículo pretende corregir esta visión. Los dos primeros apartados de este artículo describen la constitución del movimiento y los elementos supuestamente nucleares de la concepción filosófica positivista. El tercer apartado discute las discrepancias sobre el papel de la filosofía entre los autores más representativos del movimiento. Para concluir se sugiere que la vigencia del legado positivista reside no tanto en alguna tesis filosófica en particular, sino más bien en su compromiso metafilosófico con valores como la precisión y la claridad.

Bayesianism and Inference to the best explanation are two different models of inference. Recently there has been some debate about the possibility of “bayesianizing” IBE. Firstly I explore several alternatives to include explanatory considerations in Bayes’s Theorem. Then I distinguish two different interpretations of prior probabilities: “IBE-Bayesianism” and “frequentist-Bayesianism”. After detailing the content of the latter, I propose a rule for assessing the priors. I also argue that Freq-Bay: endorses a role for explanatory value in the assessment of scientific hypotheses; avoids a purely subjectivist reading of prior probabilities; and fits better than IBE-Bayesianism with two basic facts about science, i.e., the prominent role played by empirical testing and the existence of many scientific theories in the past that failed to fulfil their promises and were subsequently abandoned.

Una estrategia recientemente utilizada por los defensores deI realismo científico ha sido derivar implicaciones ontológicas deI contexto manipulativo-experimental. EI artículo pretende comparar y valorar dos enfoques diferentes deI argumento de la manipulabilidad -I. Hacking y R. Harré-, cuya idea basíca es que, de cara a establecer la existencia de una entidad, manipularla puede ser tan importante corno observarla. Por último, a fin de evitar los aspectos más cuestionables de ambos enfoques, propongo entender la eficacia manipulativa corno obtención de informacion fiable. The ‘manipulability argument’ has been reeently employed in favour of scientific realism. The underlying idea is that, in order to establish the existence of an entity, manipulating it is so important as observing it. Two different approaches to the ’manipulability argument’ are compared: Ian Hacking’s ‘experimental realism’ and Rom Harré’s ‘depth realism’. In order to avoid the most controversial aspects of both approaches, I suggest that manipulative efficacy be understood as the attainment of reliable information.

According to van Fraassen, constructive empiricism (CE) makes better sense of scientific activity than scientific realism (SR). I discuss a recent episode in biomedical research - investigations about Helicobacter Pylori and its relation to peptic ulcer. CE's expedient to cope with it is a sort of belief substitution. I argue that replacing realist beliefs by empiricist surrogates (as-if beliefs) could accommodate scientists' expectations and behavior. Nonetheless, theoretical agnosticism could hardly motivate scientists to focus just on the observational consequences derived from the theory at issue. Contrary to van Fraassen, I conclude then that, concerning scientific practice, realist beliefs cannot be considered as a gratuitious surplus which should be rejected.

The paper is a critical examination of some aspects of Laudan's views in his book Science and Values. Not only do the aims of science change; there are axiological disputes in science as well. Scientific disagreements are not solely theoretical or methodological. Progress in science consists not only in developing new theories more suitable for implementing certain epistemic values than earlier ones but also in reaching a deeper understanding of those values. The paper considers whether there are principles to guide axiological choices in science, whether the task of assessing the legitimacy of goals makes any sense. Larry Laudan's criteria to settle questions concerning the aims of science are critically canvassed. According to Laudan, axiological choices are on the same footing as the theoretical and methodological ones: all of them may be objectively grounded. The generality of the principles and their naturalistic flavour are the most remarkable merits of Laudan's account but the results are rather meagre. His principle of coherence may be, in the end, a mere a posteriori justification of changes in axiological direction carried out by the scientific community. The rejection of a demonstrable utopian goal, granting naturalistic assumptions, is completely sound but it has a very limited scope. The paper suggests that science could not demonstrate much about goals. From the rejection of semantic utopianism we can draw a need for a previous clarification rather than sustantive criticisms and, finally, Laudan's charge of epistemic utopianism is very controversial

According to the “no-miracles argument” (NMA), truth is the best explanation of the predictive-instrumental success of scientific theories. A standard objection against NMA is that it is viciously circular. In Scientific Realism: How Science Tracks Truth Stathis Psillos has claimed that the circularity objection can be met when NMA is supplemented with a reliabilist approach to justification. I will try to show, however, that scientific realists cannot take much comfort from this policy: if reliabilism makes no qualifications about the domain where inference to the best explanation is reliable, scientific realists flagrantly beg the question. A qualified version of reliabilism, on the other side, does not entitle us to infer the realist conclusion. I conclude, then, that Psillos’s proposal does not make any significant progress for scientific realism.

Ciencia, valores y relativismo discute el papel desempeñado por los valores en la práctica científica. El subtítulo del libro-una defensa de la filosofía de la ciencia-es asimismo indicativo de la posición que defiende Rodríguez Alcázar. La crisis del fundamentismo en la teoría del conocimiento, y el derrumbe de la Concepción Heredada en la filosofía de la ciencia, han llevado a cuestionar la legitimidad del propio discurso filosófico sobre la ciencia y el conocimiento. Enfoques como el pragmatismo rortyano, el anarquismo epistemológico de Feyerabend, o las escuelas sociologistas, manifiestan este rechazo. Contra estas corrientes, las tesis nucleares de Ciencia, valores y relativismo son, primero, que la filosofía de la ciencia se distingue del resto de ciencias de la ciencia por su perspectiva normativa; y, segundo, que una filosofía de la ciencia así entendida permite evitar tanto el fundamentismo como el relativismo.

Una estrategia recientemente utilizada por los defensores deI realismo científico ha sido derivar implicaciones ontológicas deI contexto manipulativo-experimental. EI artículo pretende comparar y valorar dos enfoques diferentes deI argumento de la manipulabilidad -I. Hacking y R. Harré-, cuya idea basíca es que, de cara a establecer la existencia de una entidad, manipularla puede ser tan importante corno observarla. Por último, a fin de evitar los aspectos más cuestionables de ambos enfoques, propongo entender la eficacia manipulativa corno obtención de informacion fiable. The ‘manipulability argument’ has been reeently employed in favour of scientific realism. The underlying idea is that, in order to establish the existence of an entity, manipulating it is so important as observing it. Two different approaches to the ’manipulability argument’ are compared: Ian Hacking’s ‘experimental realism’ and Rom Harré’s ‘depth realism’. In order to avoid the most controversial aspects of both approaches, I suggest that manipulative efficacy be understood as the attainment of reliable information

The paper analyzes which is the proper role of history of science in philosophy of science. I argue that, traditionally, philosophy of science has focused on the normative dimension of science. Several positions within philosophy of science stem from different perspectives on such dimension. I classify them according to two variables . Then I discuss the role of history of science within all these four alternatives. I conclude that: philosophers and historians pursue not only different, but opposite aims; historical evidence is useful for assessing the relation between methods and results; besides this, only very simple or radical philosophical views can be “refuted” by historical evidence; the disagreement between those who think that history of science is necessary for philosophy of science and those who think it is not is, in fact, a disagreement about the prospects for a generaltheory of science; such disagreement cannot be resolved appealing to historical evidence; if it can be resolved, philosophical arguments should somehow be invoked

Van Fraassen's argument from the "bad lot" challenges realist interpretations of inference to the best explanation. In this paper I begin by discussing the replies suggested by S. Psillos and P. Lipton. I do not find them convincing. However, I think that van Fraassen's argument is flawed. First of all, it is a non sequitur. Secondly, I think that the real target for the scientific realist is the underlying assumption that epistemic justification results from a comparative assessment among rival explanations. I argue that justification for believing an explanation does not depend on comparison, but on the extent that criteria of explanatory goodness are fulfilled. Therefore, in addition to offering more or less intuitive IBE-tailored arguments, realists fond of IBE should have to analyze the implicit standards of explanatory goodness. In the last section I distinguish between contextual and transcontextual criteria concerning explanatory goodness. Concerning the latter, I focus on consilience, simplicity, analogy and conservatism. \\\ Un argumento empleado por van Fraassen contra las interpretaciones realistas de la inferencia a la mejor explicación es el argumento "del mal lote". El articulo comienza discutiendo las réplicas de S. Psillos y P. Lipton. Aunque ninguna me parece convincente, pienso que el argumento de van Fraassen no resiste un examen cuidadoso. En primer lugar, la conclusión antirrealista que él extrae es un non sequitur. Además, el argumento parte de un supuesto muy cuestionable, a saber, que la justificación de una explicacion es resultado de una comparacion con sus rivales. En mi opinion, la justificación no depende de esto, sino del grado en que la explicacion satisface ciertos criterios de bondad explicativa, independientemente de que haya o no comparación. En consecuencia, la socorrida estrategia de defender el realismo cientifico basándose en la IBE pasa necesariamente por un análisis de los criterios implicitos de bondad explicativa. Mi propuesta es distinguir entre criterios contextuales y transcontextuales. En los últimos incluyo: la diversidad de la evidencia explicada, la simplicidad, la analogia y el conservadurismo.

Philip Kitcher has developed a sort of inductivist-reliabilist justification for scientific realism. After distinguishing his argument from a well-known abductivist one (the "no-miracles" argument), I will argue that Kitcher's proposal cannot adequately meet the antirealist challenge. Firstly, it begs the question against the antirealists; secondly, it can hardly support a plausible - piecemeal - scientific realism. I will explore an alternative inductivist approach that exploits correlations between theoretical properties and empirical success. On my view, its prospects for avoiding the aforementioned shortcomings are better than Kitcher's standpoint. I dare say, however, that an inductivist strategy alone cannot satisfy the demands of scientific realism since, in the end, an abductive move may well be mandatory for grounding it

El autor advierte en el prólogo que pretende reflexionar sobre la ciencia, y en particular sobre la física, “desde el punto de vista del físico que se enfrenta a algunos de los problemas filosóficos y metodológicos de su disciplina”. En esta línea, abundan en el libro interesantes referencias a episodios y temas de la física moderna. A través de ellos se intenta destilar las estrategias del físico practicante enfrentado a algunas de las cuestiones “perennes” de la filosofía de la ciencia. El enfoque es loable pues nos previene contra el peligro de elaborar una teoría sobre la ciencia divorciada de la práctica científica real, y aquí se encuentra uno de los méritos principales del libro. No obstante, el compromiso fundamental del autor es, como señala el subtítulo de la obra, con el instrumentalismo. Ésta es una posición filosófica acerca de la ciencia. Ciertamente, tal vez el instrumentalismo encaje mejor con la actitud de los científicos prácticantes que otras alternativas—lo cual podría ser un punto a su favor, por qué negarlo—, pero no deja de ser una tesis filosófica, y como tal debería ser defendida. El autor es consciente de esto, y por eso mezcla referencias a la práctica científica con consideraciones filosóficas tout court. Bien es verdad que, en general, la argumentación filosófica se reserva para criticar los rivales del instrumentalismo, mientras que las referencias a la física pretenden apoyar directamente la posición instrumentalista.