Brief response to Brian Baigrie's "The Justification of Kepler’s Ellipse" (1990).

In this article, I highlight systemic oppression related to identity construction and ontological performativity. I introduce the concept of inter-relationality as a discursive tool that builds upon intersectionality, feminist theology, and quantum entanglement theory. For a case study, I recount my experience observing sex-trafficked boys in Thailand in order to demonstrate the analytical model I present. My chief analytical guiding principle in the treatment of the case study is the way masculinity operates to re-enforce oppression. I propose queering masculinity (...) using an inter-relational perspective for the purpose of de-constructing oppressive systems and replacing them with liberative ones. (shrink)

Kepler, the father of modern physical astronomy, believed that the world is ordered by Archetypes . As quaint as this may seem, I argue that Kepler's archetypes provided methodological and epistemological solutions to problems in physical astronomy acknowledged during his time. ;Kepler used the assumption of a harmony between the archetypal and physical world to argue for the legitimacy of certain methodological innovations. The main difficulty facing astronomers at that time was the availability of observationally equivalent competing astronomical hypotheses. Kepler's (...) solution was to argue that the hypotheses could be distinguished between by proper testing and by bringing in considerations from other disciplines, especially physics. Kepler's account of the proper testing of hypotheses, though modern in appearance, was grounded in his archetypal cosmology. The use of physics in astronomy, also a modern innovation, was not considered to be methodologically sound during Kepler's time unless certain conditions were met. Under Kepler's archetypal cosmology these conditions were met, thereby legitimating the use of physics in astronomy. ;Kepler's archetypes play another role in his physical astronomy. The Aristotelian account of physics still dominant was qualitative in character. The use of mathematical physics was acceptable if it was grounded in qualitative theory, which Kepler was unable to fully provide. I argue that Kepler's archetypal cosmology enabled him to overcome this conceptual barrier. While Kepler agreed with Aristotle that mathematics is unable to reveal anything about physical causes, he believed that the archetypes are not limited in this manner. For Kepler, God's only reason for creating physical powers was to instantiate the archetypes; hence a study of archetypes can provide information about physical causes. When Kepler was unable to attach mathematical models to qualitative physical theory, he attached them to archetypal models, thereby legitimating their use in physics. ;Kepler's archetypes are no longer scientifically significant. At the time, however, they functioned to break down some of the conceptual barriers to his new physical astronomy. As a result, understanding Kepler's archetypes is of paramount importance for understanding his role in the scientific revolution of the sixteenth and seventeenth centuries. (shrink)

La question posée dans cet article est de savoir dans quelle mesure et selon quels schémas il est possible de parler de la vision sensible comme d’une représentation psychique avant la nouvelle optique inaugurée par Johannes Kepler dans ses célèbres Paralipomena ad Vitellionem (1604). L’article part du point de vue suivant : c’est seulement à l’intérieur de ce nouveau paradigme, qui dissocie le processus physique de la vision de son traitement psychique, qu’il serait légitime de parler de la vision comme (...) une construction mentale, comme une représentation. En examinant cette question à la lumière de plusieurs théories anciennes et médiévales, l’article aboutit à une conclusion différente. C’est depuis Aristote que la question de la vision comme représentation mentale est posée, du fait de la fonction majeure qui est conférée aux sens internes (phantasia, sens commun) dans l’élaboration du contenu de perception, et certaines théories sous influence néo-platonicienne, comme celles d’Augustin ou Avicenne, conçoivent clairement la vision directe comme une représentation psychique. Dans les Paralipomena ad Vitellionem, Kepler sépare l’optique comme science physique de la lumière de la psychologie de la perception ; mais cette dernière a déjà une longue histoire, tout comme l’idée de la vision comme représentation mentale. (shrink)

The development of physical theory is one of our greatest intellectual achievements. Its products--the currently prevailing theories of physics, astronomy, and cosmology--have proved themselves to possess intrinsic beauty and to have enormous explanatory and predictive power. This anthology of primary readings chronicles the birth and maturation of five such theories (the heliocentric theory, the electromagnetic field theory, special and general relativity, quantum theory, and the big bang theory) in the words of the scientists who brought (...) them to life. It is the first historical account that captures the rich substance of these theories, each of which represents a fascinating story of the interplay of evidence and insight--and of dialogue among great minds. Readers sit in with Copernicus, Kepler, and Galileo as they overturn the geocentric universe; observe the genius of Faraday and Maxwell as they "discover" the electromagnetic field; look over Einstein's shoulder as he works out the details of relativity; listen in as Einstein and Bohr argue for the soul of quantum mechanics in the Completeness Debate; and watch as Hubble and others reveal the history of the universe. The editors' approach highlights the moments of discovery that rise from scientific creativity, and the presentation humanizes the scientific process, revealing the extent to which great scientists were the first to consider the philosophical implications of their work. But, most significantly, the editors offer this as their central thesis: although each was ushered in by a revolution, and each contains counterintuitive elements that delayed its acceptance, these five theories exhibit a continuous rational development that has led them to a permanent place in the worldview of science. Accessible to the general reader yet sufficiently substantive that working scientists will find value in it, The Tests of Time offers an intimate look into how physical theory has been developed, by the brilliant people who have developed it. (shrink)

Following Kuhn's main thesis according to which theory revision and acceptance is always paradigm relative, I propose to outline some possible consequences of such a view. First, asking the question in what sense Bayesian decision theory could serve as the appropriate (normative) theory of rationality examined from the point of view of the epistemology of theory acceptance, I argue that Bayesianism leads to a narrow conception of theory acceptance. Second, regarding the different types of (...) class='Hi'>theory revision, i.e. expansion, contraction, replacement and residuals shifts, I extract from Kuhn's view a series of indications showing that theory replacement cannot be rationalized within the framework of Bayesian decision theory, not even within a more sophisticated version of that model. Third, and finally, I will point to the need for a more comprehensive model of rationality than the Bayesian expected utility maximization model, the need for a model which could better deal with the different aspects of theory replacement. I will show that Kuhn's distinction between normal and revolutionary science gives us several hints for a more adequate theory of rationality in science. I will also show that Kuhn is not in a position to fully articulate his main ideas and that he well be confronted with a serious problem concerning collective choice of a paradigm. (shrink)

Following Kuhn's main thesis according to which theory revision and acceptance is always paradigm relative, I propose to outline some possible consequences of such a view. First, asking the question in what sense Bayesian decision theory could serve as the appropriate (normative) theory of rationality examined from the point of view of the epistemology of theory acceptance, I argue that Bayesianism leads to a narrow conception of theory acceptance. Second, regarding the different types of (...) class='Hi'>theory revision, i.e. expansion, contraction, replacement and residuals shifts, I extract from Kuhn's view a series of indications showing that theory replacement cannot be rationalized within the framework of Bayesian decision theory, not even within a more sophisticated version of that model. Third, and finally, I will point to the need for a more comprehensive model of rationality than the Bayesian expected utility maximization model, the need for a model which could better deal with the different aspects of theory replacement. I will show that Kuhn's distinction between normal and revolutionary science gives us several hints for a more adequate theory of rationality in science. I will also show that Kuhn is not in a position to fully articulate his main ideas and that he well be confronted with a serious problem concerning collective choice of a paradigm. (shrink)

This paper ties together three threads of discussion about the following question: in accepting a system of axioms S, what else are we thereby warranted in accepting, on the basis of accepting S? First, certain foundational positions in the philosophy of mathematics are said to be epistemically stable, in that there exists a coherent rationale for accepting a corresponding system of axioms of arithmetic, which does not entail or otherwise rationally oblige the foundationalist to accept statements beyond the logical consequences (...) of those axioms. Second, epistemic stability is said to be incompatible with the implicit commitment thesis, according to which accepting a system of axioms implicitly commits the foundationalist to accept additional statements not immediately available in that theory. Third, epistemic stability stands in tension with the idea that in accepting a system of axioms S, one thereby also accepts soundness principles for S. We offer a framework for analysis of sets of implicit commitment which reconciles epistemic stability with the latter two notions, and argue that all three ideas are in fact compatible. (shrink)

Recent arguments for scientific realism have emphasized the importance of both methodological factors, such as theoretical unification , and experiments , as evidence for a realistic view of certain aspects of theoretical structure . Throughout this dissertation I argue that neither strategy is sufficient as a defense of realism. ;Chapter one consists of a discussion of Friedman's argument for realism as outlined in his Foundations of Space-Time Theories . I argue that his reliance on theoretical unification and conjunction as grounds (...) for a selective brand of realism is unsatisfactory for a variety of reasons. Not only does his structure-substructure reductivist model of theories and the emphasis on conjunction fail to fit actual cases of theory evolution, but the historical relativity built into the approach is undesirable even from a realist perspective. The relationship between conjunctive inference and unification is discussed and it is suggested that although theoretical unification is desirable at some stages of theory development it contributes nothing to the justification or evidential warrant of theories. ;In chapter two my claims regarding unification are applied to the development of Maxwell's electromagnetic theory. I discuss the difficulties in specifying a workable model of the aether as the unifying theoretical structure as well as the importance of models and analogies in Maxwell's work. It is argued that this obvious unification of electromagnetism and optics played virtually no evidential role in the final acceptance of the theory. It was not until the completion of Hertz's experiments that Maxwell's theory was actually vindicated. ;Chapter three focuses on the experimental difficulties associated with Maxwell's theory and the relationship between Hertz's experiments and his theoretical interpretation of electromagnetism. ;In chapter four I summarize some of the general difficulties associated with the notion of independent evidence as it pertains to experimental results. I conclude by arguing that although experiment provides a more persuasive case for realism than methodological factors, in many instances it fails to provide the kind of epistemological justification required for the realist assumptions about the ontology of scientific theories. (shrink)

The state of science at any given time is characterized, in part at least, by the theories that are accepted at that time. Presently accepted theories include quantum theory, the general theory of relativity, and the modern synthesis of Darwin and Mendel, as well as lower‐level (but still clearly theoretical) assertions such as that DNA has a double‐helical structure, that the hydrogen atom contains a single electron, and so on. What precisely is involved in accepting a theory?

The state of science at any given time is characterized, in part at least, by the theories that are accepted at that time. Presently accepted theories include quantum theory, the general theory of relativity, and the modern synthesis of Darwin and Mendel, as well as lower‐level (but still clearly theoretical) assertions such as that DNA has a double‐helical structure, that the hydrogen atom contains a single electron, and so on. What precisely is involved in accepting a theory?

Neurath's proposal for the form of protocol statements explicates the multiple embedding of a singular sentence as specifying different conditions for the acceptance of such a sentence as a bona fide scientific datum. Before theories are accepted or rejected in the light of such evidence, however, a further condition must be met which Neurath did not formalize. The different conditions are discussed and shown to constitute a naturalistic theory of scientific data and a pragmatic theory of theory (...) acceptance. (shrink)

Kepler is mainly known among historians of science for his astronomical theories and his approaches to problems having to do with philosophy of science and ontology. This paper attempts to contribute to Kepler studies by providing a discussion of a topic not frequently considered, namely Kepler’s theory of the soul, a general theory of knowledge whose central problem is what makes knowledge possible, rather than what makes knowledge true, as happens in the case of Descartes’s and Bacon’s epistemologies. (...) Kepler’s theory consists of four issues: the theory of the different sorts of soul—that is, the human soul, the animal soul, the vegetable soul, and the Earth soul—concerning their faculties, the differences and the resemblances emerging among them, the relation they maintain with their own bodies and the world, and the distinction soul–world. The paper discusses these issues from a historical perspective, that is, it reconstructs the way they appear in three periods of Kepler’s career: the period prior to the publication of the Mysterium cosmographicum, the period from 1596 to 1611, and the period of the Harmonices mundi libri V. Finally, Kepler’s epistemology is briefly contrasted with Descartes’s and Bacon’s in order to suggest that Kepler’s could be seen as a third way to understand the philosophical origins of Modernity.Keywords: Johannes Kepler; René Descartes; Francis Bacon; Anima; Force; Animism. (shrink)

After a thorough examination of the claim that "the underdetermination of theory by evidence forces us to seek sociological explanations of scientists' cognitive choices", Samir Okasha concludes that the only significant problem with this argument is that the thesis of underdetermination is not adequately supported. Against Okasha, I argue (1) that there is a very good reason to question the inference from the underdetermination of a theory to a sociological account of that theory's acceptance, and (2) that (...) Okasha's own objection to the argument is too weak. (shrink)

Dawes (2013) claims that we ought not to believe but to accept our best scientific theories. To accept them means to employ them as premises in our reasoning with the goal of attaining knowledge about unobservables. I reply that if we do not believe our best scientific theories, we cannot gain knowledge about unobservables, our opponents might dismiss the predictions derived from them, and we cannot use them to explain phenomena. We commit an unethical speech act when we explain a (...) phenomenon in terms of a theory we do not believe. (shrink)

In his Paralipomena Johannes Kepler reported an experimentum that he had seen in the Dresden Kunstkammer. In one of the rooms there, which had been turned in its entirety into a camera obscura, he had witnessed the images formed by a lens. I discuss the role of this experiment in the development and foundation of his new theory of optical imagery, which made a distinction between two concepts of image, pictura and imago. My focus is on how Kepler used (...) his report of the experiment inside the camera obscura to criticize the account of image formation given in Giovanbattista Della Porta's Magia naturalis . I argue that this experiment allowed Kepler to sort out the confusion between images 'in the air'—referring to the geometrical locus of images in the perspectivist tradition of optics—and the experimentally produced 'projected images', which were empirically familiar but conceptually alien to perspectivist optics. (shrink)

This This paper examines the acceptance and criticism of Zhuzi(朱子)’s Zhonghe(中和) theory in the Choseon Jingxue(經學) of the 16th and 17th Centuries. In order to discuss the Zhuzi(朱子)’s Zhonghe(中和) theory, I first thought that the conceptual analysis of Doctrine of the Mean(中庸) is necessary for the ‘喜怒哀樂之未發謂之中, 發而皆中節謂之和’. As a result of this analysis, it was confirmed that the concept of Zhonghe(中和) of Doctrine of the Mean(中庸) was basically a matter of feeling. This indicates that the Zhonghe(中和) idea (...) of Doctrine of the Mean(中庸) takes the issue of feeling more important than reason. This point can be understood as a dimension of the same context in that Western thought emphasizes reason and Eastern thought emphasizes emotion. It is judged that the Zhonghe(中和) idea of Doctrine of the Mean(中庸) centering on this feeling of appreciation has led to the time of the Lijizhushu(禮記注疏). This Zhonghe(中和) thought based on emotion of Doctrine of the Mean(中庸) is newly interpreted by the Cheng-Zhu School(程朱學). Especially, the recognition of ‘Zhong(中)’ in the Weifa(未發) as Li(理) can be called a great change in the mind-nature theory(心性論) of Doctrine of the Mean(中庸). This interpretation of Zhonghe(中和) was largely accepted in the 16th and 17th century Choseon Dynasty, and the representative character is Cho Ik(趙翼). On the other hand, there was also a person who did not accept this interpretation of Zhonghe(中和) as it was. The representative figure is Park Sedang. Park Sedang was unable to accept Zhu Xi’s philosophical interpretation of Weifa(未發) in his perception of Zhonghe(中和) theory. He recognized that in human mind there could hardly be a state of Weifa(未發) in which a glimmer of thought does not arise. This is why he did not accept Zhu xi’s philosophical interpretation of considering the state of 'Weifa(未發) as ‘Jiran-Budong(寂然不動)’. I think that Park Sedang's view on Zhonghe(中和) is closer to the previous Zhonghe theory(中和舊說) of Zhu Xi. (shrink)

Drawing on diverse historical cases, this paper describes and examines various aspects of a modality of scientific appraisal which has remained largely unexplored, theory pursuit. Specifically, it addresses the following issues: the epistemic and pragmatic commitments involved in theory pursuit, including how these differ from those characteristic of theory acceptance; how the research interests of scientists enter into their pursuit decisions; some of the strategies for the refinement and extension of a theory's empirical abilities which typify (...) theory pursuit; and the need to distinguish between individual and community rationality in contexts of pursuit. (shrink)

In his Paralipomena Johannes Kepler reported an experimentum that he had seen in the Dresden Kunstkammer. In one of the rooms there, which had been turned in its entirety into a camera obscura, he had witnessed the images formed by a lens. I discuss the role of this experiment in the development and foundation of his new theory of optical imagery, which made a distinction between two concepts of image, pictura and imago. My focus is on how Kepler used (...) his report of the experiment inside the camera obscura to criticize the account of image formation given in Giovanbattista Della Porta's Magia naturalis. I argue that this experiment allowed Kepler to sort out the confusion between images 'in the air'—referring to the geometrical locus of images in the perspectivist tradition of optics—and the experimentally produced 'projected images', which were empirically familiar but conceptually alien to perspectivist optics. (shrink)

In this paper we aim to contribute to the recent debate on non-empirical theory confirmation by analyzing why scientists accept and trust their theories in the absence of clear empirical verification in social sciences. Given that the philosophy of social sciences traditionally deals mainly with economics and sociology, organization theory promises a new area for addressing a wide range of key questions of the modern philosophy of science and, in particular, to shed a light on the puzzling question (...) of non-empirical theory assessment, acceptance, corroboration and development. Although institutional theory of organizations cannot be directly tested and evaluated via empirical data, this theory nevertheless became a dominant theory of organization-environment relations and most organizational researchers routinely use it as a standard theoretical framework for making sense of empirical findings. We analyze the trajectory of institutional theory development and proliferation and argue that it enjoys its current status of the standard theory of organizational sociology because (1) it is flexible enough to account for most organizational processes and phenomena; (2) it has suppressed existing alternative theories that are less flexible; (3) because scientists do not tend to look for alternatives for once winning theory and (4) due to the dysfunctional requirement to “develop theory” in top journals in organization and management studies. Finally, we argue that “a too-much-plasticity effect”, has a negative impact on institutional theory in the long run. It is explained why, despite the dominant position in organizational research, institutional studies cannot be regarded as a normal science while the progress of this theoretical problem is rather an illusory effect then a growth of knowledge. (shrink)

This investigation examined how people’s beliefs about the functionality of emotion shape their emotional response and regulatory strategies when encountering distressing events. In Study 1, we present data supporting the reliability and validity of an 8-item instrument, the Help and Hinder Theories about Emotion Measure (HHTEM), designed to assess an individual’s beliefs about the functionality of emotion. Participants who more strongly endorsed a Help Theory reported greater wellbeing, emotional acceptance, and use of reappraisal to regulate emotion. Participants who more (...) strongly endorsed a Hinder Theory reported less wellbeing and more expressive suppression and substance use. In Study 2, we demonstrate that encouraging participants to view emotion as helpful affected their physiological and regulatory response to a distressing event. Participants in the Help Theory condition showed greater physiological reactivity (SCL) during a distressing film than control participants but were more accepting of their emotional response. Shortly after the film, SCL decreased for participants in the Help Theory condition. Compared to control participants, they engaged in less suppression and reported less lingering effect of the film on their mood. Together, these studies suggest that people’s theories about the functionality of emotion influence their reactivity, the strategies they adopt to regulate emotion, and their ability to rebound after distressing events. (shrink)

BackgroundThe brain death standard allowing a declaration of death based on neurological criteria is legally endorsed and routinely practiced in the West but not in Asia. In China, attempts to legalize the brain death standard have occurred several times without success. Cultural, religious, and philosophical factors have been proposed to explain this difference, but there is a lack of empirical studies to support this hypothesis.Methods476 medical providers from three academic hospitals in Hunan, China, completed a selfadministered survey including a 12-question (...) brain death clinical knowledge assessment and hypothetical vignettes describing brain dead patients.ResultsThe response rate was 95.2 %. Almost all of the providers had heard of the term “brain death.” More than half have encountered presumed brain dead patients. Two-thirds accepted brain death as an ethical standard to determine human death. The mean knowledge score was 8.50 ± 1.83 out of 12. When given the description of a brain dead patient, 50.7 % considered the patient dead, 51.9 % would withdraw life support, and 40.6 % would allow organ procurement. Both provider and patient characteristics contributed to the providers’ decisions. Ethical acceptance was the most important independent predictor for brain death acknowledgement, followed by high knowledge scores, and the belief that the soul lives in the brain. Religious faith and associated beliefs did not have a significant effect.ConclusionsNotwithstanding scarce official accounts, recognition of the brain death standard is not uncommon in China. Chinese medical providers can adequately define the medical characteristics of brain death and accept it in theory, but hesitate to apply it to practice in the vignettes. Legalization is paramount in providing the protection providers need to comfortably declare brain death. However the medical decision-making surrounding brain death is complex and the provider's past experiences and emotions may also influence the process. (shrink)

This paper argues that Kepler considered his work in optics as part of natural philosophy and that, consequently, he aimed at change within natural philosophy. Back-to-back with John Schuster’s claim that Descartes’ optics should be considered as a natural philosophical appropriation of innovative results in the tradition of practical and mixed mathematics the central claim of my paper is that Kepler’s theory of optical imagery, developed in his Paralipomena ad Vitellionem (1604), was the result of a move similar to (...) Descartes’ by Kepler. My argument consists of three parts. First, Kepler borrowed a geometrical model and experiment of optical imagery from the mélange of mixed and practical mathematics provided in the works of the sixteenth-century mathematicians Ettore Ausonio and Giovanni Battista Della Porta. Second, Kepler criticized the Aristotelian theory of light and he developed his own alternative metaphysics. Third, Kepler used his natural philosophical assumptions about the nature of light to re-interpret the model of image formation taken from Della Porta’s work. Taken together, I portray Kepler’s theory of optical imagery as a natural philosophical appropriation of an innovative model of image formation developed in a sixteenth-century practical and mixed mathematical tradition which was not interested in questioning philosophical assumptions on the nature of light. (shrink)

Scientists typically do something other than accept or reject their theories, they pursue them. Throughout the greater part of the nineteenth century numerous chemists devoted their research energy and resources to the development of Daltonian theory, declaring themselves willing to make use of the atomic theory in their research but reluctant or unwilling to accept it. When Frankland, for example, declared that he did not want to be considered a “blind believer” in the atomic theory and could (...) not “accept it as true”, but that he had been—and planned to continue—using it “as a useful ladder”, he had arrived at a decision shared by many of his colleagues that while the theory was not acceptable, it was promising and worthy of pursuit.1 And when Van’t Hoff measured the kinetic-molecular theory by its fruits in the 1880’s, he judged that it barely gave the then-current 4% interest rate, and so was an unpromising theory, unworthy of pursuit (van Nelsen 1960. p. 151). (shrink)

The rhetoric-analytic critique of experimental psychology owes its apparent attractiveness to (a) some erroneous ideas about cognitive psychology and the rationale of experimentation, (b) the failure to distinguish between prior data and evidential data vis-à-vis the to-be-corroborated explanatory theory, and (c) evidential data owes their identity to a theory that is independent of the theory being tested. Theories in cognitive psychology are accepted because they can withstand concerted efforts to falsify them.

It has been argued that reduction procedures are closely connected to the question about identity of proofs and that accepting certain reductions would lead to a trivialization of identity of proofs in the sense that every derivation of the same conclusion would have to be identified. In this paper it will be shown that the question, which reductions we accept in our system, is not only important if we see them as generating a theory of proof identity but is (...) also decisive for the more general question whether a proof has meaningful content. There are certain reductions which would not only force us to identify proofs of different arbitrary formulas but which would render derivations in a system allowing them meaningless. To exclude such cases, a minimal criterion is proposed which reductions have to fulfill to be acceptable. (shrink)

I begin chapter I by discussing two key distinctions that constitute the core of van Fraassen's constructive empiricism: a distinction between observables and unobservables and a distinction between acceptance and belief with regard to a theory. To support constructive empiricism, van Fraassen also deploys two epistemological principles: only actual observations are to be taken as evidence and possible evidence is all that can be rationally inferred from the actual evidence. I reject both principle and van Fraassen's construal of observation. (...) As does van Fraassen, I make the distinction between acceptance and belief in chapter II. I contend that one does not need to be an antirealist to espouse this distinction between acceptance and belief. ;In the remaining chapters, I develop a quasi-Bayesian account of acceptance as an alternative to van Fraassen's. In chapter III, I consider three views of acceptance: van Fraassen's, Bayesian views, and the epistemic view. I argue that both van Fraassen's account and the epistemic account are open to Bayesian objections. However, Bayesianism assumes a controversial principle called "maximization of expected utility" , which might mitigate the impact of the Bayesian objections. ;In the final chapter, I consider different decision principles, e.g. Kyburg's decision principle, and Gardenfors and Sahlin's decision principle. I formulate a decision principle called the "weak-dominance-decision principle " based on Kyburg's theory . The interval-based probability yields, as a limiting case, the point-valued probability when we have complete information about the event in question. In this case, my decision principle reduces to MEU. Therefore, the same Bayesian objections against both van Fraassen's theory of acceptance and the epistemic theory of acceptance could be made from the perspective of my decision principle while escaping the perils of strict Bayesianism. My theory of acceptance is quasi-Bayesian, because WDP rests on interval-based probability. (shrink)

The discrepancy between the Aristotelian and the Ptolemaic astronomies led many medievals to regard the latter (and mathematical astronomy generally) as no more than a calculational device. This was the challenge that Copernicus and Kepler had to meet: How was one to show that a mathematically expressed astronomy could indicate that the earth really moves? Copernicus pointed to features of the planetary motions that he could explain but that Ptolemy could not. Kepler went much further. His account of the planetary (...) system yields a passable theory of why the planets move as they do; the geocentric account (now without the support of carrier spheres) most certainly cannot. The basic hypothesis that the sun is really at the center and the earth really in motion, he claims, is thus likely to be true. (shrink)

When Kepler concluded that the orbit of Mars was not a circle, he was led to the belief that the orbit was an oval touching the circle at the apsides and lying within the circle at other points. In the definition of the oval, physical hypotheses played a primary role. Two forces were involved; a tractive force arising from the effect of the solar rays rotating with the sun, and a directing force arising from a natural instinct of the planet (...) itself. The former pushed the planet along the orbit while the latter enabled the planet to steer itself across the stream of the solar vortex in a small epicycle. In adopting this physical theory to determine the oval, Kepler was led into what he himself described as ‘a new labyrinth’. After several attempts to construct the oval, and by progressively eliminating the sources of error from his calculating procedures in order to arrive at an accurate mathematical formulation of the physical hypotheses, he was able to conclude that the oval was inconsistent with the empirical data and the physical theory in need of modification. (shrink)

The year 2009 marks the 400th anniversary of the publication of one of the most revolutionary scientific texts ever written. In this book, appropriately entitled, Astronomia nova, Johannes Kepler developed an astronomical theory which departs fundamentally from the systems of Ptolemy and Copernicus. One of the great innovations of this theory is its dependence on the science of optics. The declared goal of Kepler in his earlier publication, Paralipomena to Witelo whereby The Optical Part of Astronomy is Treated, (...) was to solve difficulties and expose illusions astronomers face when conducting astronomical observations with optical instruments. To avoid observational errors that had plagued the antiquated measuring techniques for calculating the apparent diameter and angular position of the luminaries, Kepler designed a novel device: the ecliptic instrument. In this paper we seek to shed light on the role optical instruments play in Kepler's scheme: they impose constraints on theory, but at the same time render astronomical knowledge secure. To get a comprehensive grasp of Kepler's astonishing achievements it is required to widen the approach to his writings and study Kepler not only as a mathematico-physical astronomer, but also as a designer of instruments and a practicing observer. (shrink)

It is argued that we need a richer version of Bayesian decision theory, admitting both subjective and objective probabilities and providing rational criteria for choice of our prior probabilities. We also need a theory of tentative acceptance of empirical hypotheses. There is a discussion of subjective and of objective probabilities and of the relationship between them, as well as a discussion of the criteria used in choosing our prior probabilities, such as the principles of indifference and of maximum (...) entropy, and the simplicity ranking of alternative hypotheses. (shrink)