Experimentation in the cosmic laboratory

It might seem impossible to apply Ian Hacking's experimental argument for scientific realism to astrophysical objects; indeed Hacking himself expressed scepticism about extragalactic entities. Such astrophysical antirealism has been the subject of intense debate and is usually seen as an undesired consequence of experimental realism. In this paper, I claim that it is possible to recast the experimental argument by reference to James Woodward's non-anthropocentric account of experimentation so as to apply it to astrophysical entities, such as gravitational lenses. I also argue that this new formulation of the experimental argument solves several problems with Hacking's original version.     

Species concepts,process analysis,and the hierarchy of nature

Species figure prominently in all biological studies, but what a species actually is and how we recognize it in practice is still a much-debated issue. Present discussion revolves around five major species concepts: the biological, the evolutionary, the cladistic, the recognition and the phylogenetic concepts. Each of these species notions has its theoretical and practical problems. One important point that has emerged from recent discussions on the ontological status of species is that there is a tension between species concepts based on interbreeding and those based on genealogy, and that practical application of these two kinds of concept may give rise to incompatible results. Species recognized by one species concept appear to be essentially different entities compared with species demarcated by another. However, these different species may all represent real and objective entities in nature. What we perceive as a species depends on the evolutionary processes that we have made objects of our research. Some of these processes are between entities of the genealogical hierarchy of nature, while other processes relate to nature's ecological hierarchy. It is essential that our species concept should be adjusted to the focal level of our research program, thereby taking into full account the two process hierarchies of nature.     

A philosophical study of the transition from the caloric theory of heat to thermodynamics: Resisting the pessimistic meta-induction

I began this study with Laudan's argument from the pessimistic induction and I promised to show that the caloric theory of heat cannot be used to support the premisses of the meta-induction on past scientific theories. I tried to show that the laws of experimental calorimetry, adiabatic change and Carnot's theory of the motive power of heat were (i) independent of the assumption that heat is a material substance, (ii) approximately true, (iii) deducible and accounted for within thermodynamics.I stressed that results (i) and (ii) were known to most theorists of the caloric theory and that result (iii) was put forward by the founders of the new thermodynamics. In other words, the truth-content of the caloric theory was located, selected carefully, and preserved by the founders of thermodynamics.However, the reader might think that even if I have succeeded in showing that laudan is wrong about the caloric theory, I have not shown how the strategy followed in this paper can be generalised against the pessimistic meta-induction. I think that the general strategy against Laudan's argument suggested in this paper is this: the empirical success of a mature scientific theory suggests that there are respects and degrees in which this theory is true. The difficulty for — and and real challenge to — philosophers of science is to suggest ways in which this truth-content can be located and shown to be preserved — if at all — to subsequent theories. In particular, the empirical success of a theory does not, automatically, suggest that all theoretical terms of the theory refer. On the contrary, judgments of referential success depend on which theoretical claims are well-supported by the evidence. This is a matter of specific investigation. Generally, one would expect that claims about theoretical entities which are not strongly supported by the evidence or turn out to be independent of the evidence at hand, are not compelling. For simply, if the evidence does not make it likely that our beliefs about putative theoretical entities are approximately correct, a belief in those entities would be ill-founded and unjustified. Theoretical extrapolations in science are indespensable , but they are not arbitrary. If the evidence does not warrant them I do not see why someone should commit herself to them. In a sense, the problem with empricist philisophers is not that they demand that theoretical beliefs must be warranted by evidence. Rather, it is that they claim that no evidence can warrant theorretical beliefs. A realist philosopher of science would not disagree on the first, but she has good grounds to deny the second.I argued that claims about theoretical entities which are not strongly supported by the evidence must not be taken as belief-worthy. But can one sustaon the more ambitious view that loosely supported parts of a theory tend to be just those that include non-referring terms? There is an obvious excess risk in such a generalisation. For there are well-known cases in which a theoretical claim was initially weakly supported by the evidence     

Representing with imaginary models: Formats matter

Models such as the simple pendulum, isolated populations, and perfectly rational agents, play a central role in theorising. It is now widely acknowledged that a study of scientific representation should focus on the role of such imaginary entities in scientists’ reasoning. However, the question is most of the time cast as follows: How can fictional or abstract entities represent the phenomena? In this paper, I show that this question is not well posed. First, I clarify the notion of representation, and I emphasise the importance of what I call the “format” of a representation for the inferences agents can draw from it. Then, I show that the very same model can be presented under different formats, which do not enable scientists to perform the same inferences. Assuming that the main function of a representation is to allow one to draw predictions and explanations of the phenomena by reasoning with it, I conclude that imaginary models in abstracto are not used as representations: scientists always reason with formatted representations. Therefore, the problem of scientific representation does not lie in the relationship of imaginary entities with real systems. One should rather focus on the variety of the formats that are used in scientific practice.     

The Whewell-Mill debate on predictions,from Mill's point of view

John Stuart Mill, in his debate with William Whewell on the nature and logic of induction, is regarded as being the first to dismiss the supposed value of successful predictions as merely psychological. I shall argue that this view of the Whewell-Mill debate on predictions misconstrues Mill’s position and argument. From Mill’s point of view, the controversial point was not the question whether predictions ‘count more’ than ex-post explanations but the alleged assertion by Whewell that the successful predictions of the wave theory of light prove the existence of the ether. Mill argued that, on the one hand, the predictions of the wave theory of light do not and cannot provide evidence for the existence of the ether; as evidence for the laws of the theory, on the other hand, the predictions are superfluous, the laws being already well-confirmed. Mill actually endorsed a requirement of independent support closely resembling Whewell’s requirements for hypotheses; the controversy on the value of predictions is a product of the 20th century.     

The roots of the silver tree: Boyle,alchemy, and teleology

Though Robert Boyle called final causes one of the most important subjects for a natural philosopher to study, his own treatise on the subject, the Disquisition about Final Causes, has received comparatively little scholarly attention. In this paper, I explicate Boyle's complex argument against the use of teleological explanations for inanimate bodies, such as metals. The central object of this argument is a mysterious allusion to a silver plant. I claim that the silver plant is best understood as a reference to alchemical product: the Arbor Dianae, an offshoot of George Starkey's recipe for the Philosophers' Stone. Then, I show how the context of alchemy not only clarifies Boyle's argument but also places it within a wider dialectic about matter and teleology. I then contrast the parallel arguments of Boyle and John Ray on the question of whether metals have divine purposes and show that the difference is explained by Boyle's belief in the transmutation of metals.     

Constructive empiricism, observability and three kinds of ontological commitment

In this paper, I argue that, contrary to the constructive empiricist’s position, observability is not an adequate criterion as a guide to ontological commitment in science. My argument has two parts. First, I argue that the constructive empiricist’s choice of observability as a criterion for ontological commitment is based on the assumption that belief in the existence of unobservable entities is unreasonable because belief in the existence of an entity can only be vindicated by its observation. Second, I argue that the kind of ontological commitment that is under consideration when accepting a scientific theory is commitment to what I call theoretical kinds and that observation can vindicate commitment to kinds only in exceptional cases.     

A loose and separate certainty: Caves, Fuchs and Schack on quantum probability one

Carlton Caves, Fuchs, and Schack (2002) have recently appealed to an argument of mine (Stairs, 1983) to address a problem for their subjective Bayesian account of quantum probability. The difficulty is that on the face of it, quantum mechanical probabilities of one appear to be objective, but in that case, the Born Rule would yield a continuum of probabilities between zero and one. If so, we end up with objective probabilities strictly between zero and one. The authors claim that objective probabilities of one leads to a dilemma: give up locality or fall into contradiction. I argue that this conclusion depends on an overly strong interpretation of objectivism about quantum probabilities.     

The total cost of misclassification in credit scoring: A comparison of generalized linear models and generalized additive models

This study examines whether the evaluation of a bankruptcy prediction model should take into account the total cost of misclassification. For this purpose, we introduce and apply a validity measure in credit scoring that is based on the total cost of misclassification. Specifically, we use comprehensive data from the annual financial statements of a sample of German companies and analyze the total cost of misclassification by comparing a generalized linear model and a generalized additive model with regard to their ability to predict a company's probability of default. On the basis of these data, the validity measure we introduce shows that, compared to generalized linear models, generalized additive models can reduce substantially the extent of misclassification and the total cost that this entails. The validity measure we introduce is informative and justifies the argument that generalized additive models should be preferred, although such models are more complex than generalized linear models. We conclude that to balance a model's validity and complexity, it is necessary to take into account the total cost of misclassification.     

On the normative dimension of the St. Petersburg paradox

In this paper I offer an account of the normative dimension implicit in D. Bernoulli’s expected utility functions by means of an analysis of the juridical metaphors upon which the concept of mathematical expectation was moulded. Following a suggestion by the late E. Coumet, I show how this concept incorporated a certain standard of justice which was put in question by the St. Petersburg paradox. I contend that Bernoulli would have solved it by introducing an alternative normative criterion rather than a positive model of decision making processes.     

On Popper’s strong inductivism (or strongly inconsistent anti-inductivism)

It is generally accepted that Popper‘s degree of corroboration, though “inductivist” in a very general and weak sense, is not inductivist in a strong sense, i.e. when by ‘inductivism’ we mean the thesis that the right measure of evidential support has a probabilistic character. The aim of this paper is to challenge this common view by arguing that Popper can be regarded as an inductivist, not only in the weak broad sense but also in a narrower, probabilistic sense. In section 2, first, I begin by briefly characterizing the relevant notion of inductivism that is at stake here; second, I present and discuss the main Popperian argument against it and show that in the only reading in which the argument is formally it is restricted to cases of predicted evidence, and that even if restricted in this way the argument is formally valid it is nevertheless materially unsound. In section 3, I analyze the desiderata that, according to Popper, any acceptable measure for evidential support must satisfy, I clean away its ad-hoc components and show that all the remaining desiderata are satisfied by inductuvist-in-strict-sense measures. In section 4 I demonstrate that two of these desiderata, accepted by Popper, imply that in cases of predicted evidence any measure that satisfies them is qualitatively indistinguishable from conditional probability. Finally I defend that this amounts to a kind of strong inductivism that enters into conflict with Popper’s anti-inductivist argument and declarations, and that this conflict does not depend on the incremental versus non-incremental distinction for evidential-support measures, making Popper’s position inconsistent in any reading.     

Does democracy require value-neutral science? Analyzing the legitimacy of scientific information in the political sphere

Philosophers now commonly reject the value free ideal for science by arguing that non-epistemic values, including personal or social values, are permissible within the core of scientific research. However, little attention has been paid to the normative political consequences of this position. This paper explores these consequences and shows how political theory is fruitful for proceeding in a world without value-neutral science. I draw attention to an oft-overlooked argument employed by proponents of the value free ideal I dub the “political legitimacy argument.” This argument claims that the value-free ideal follows directly from the foundational principles of liberal democracy. If so, then the use of value-laden scientific information within democratic decision making would be illegitimate on purely political grounds. Despite highlighting this unaddressed and important argument, I show how it can be rejected. By appealing to deliberative democratic theory, I demonstrate scientific information can be value-laden and politically legitimate. The deliberative democratic account I develop is well suited for capturing the intuitions of many opponents of the value free ideal and points to a new set of questions for those interested in values in science.     

The material theory of induction and the epistemology of thought experiments

John D. Norton is responsible for a number of influential views in contemporary philosophy of science. This paper will discuss two of them. The material theory of induction claims that inductive arguments are ultimately justified by their material features, not their formal features. Thus, while a deductive argument can be valid irrespective of the content of the propositions that make up the argument, an inductive argument about, say, apples, will be justified (or not) depending on facts about apples. The argument view of thought experiments claims that thought experiments are arguments, and that they function epistemically however arguments do. These two views have generated a great deal of discussion, although there hasn't been much written about their combination. I argue that despite some interesting harmonies, there is a serious tension between them. I consider several options for easing this tension, before suggesting a set of changes to the argument view that I take to be consistent with Norton's fundamental philosophical commitments, and which retain what seems intuitively correct about the argument view. These changes require that we move away from a unitary epistemology of thought experiments and towards a more pluralist position.     

On the alleged non-existence of orbitals

I argue that the claim made by Scerri that in many-electron atoms, orbitals do not exist according to quantum mechanics, is incorrect, for it relies on the view that orbitals are entities. Orbitals are states, not entities, and their use in describing many-electron atoms should be seen as an approximation. The writings by Scerri and others on the issue of realism that are based on the claim therefore lead astray. I furthermore disentangle two issues that Scerri discusses in arguing for his claim: that of electron correlation and that of the Pauli principle. Finally, I point out that more generally there is a misconception in chemistry of what quantum states are.     

Finding your marbles in wavefunction collapse theories

Lewis (Br. J. Philos. Sci. 48 (1997) 313) has recently presented an argument claiming that, under the Ghirardi–Rimini–Weber (GRW) theory of quantum mechanics, arithmetic does not apply to ordinary macroscopic objects such as marbles (known as the Counting Anomaly). In this paper, I disentangle two different lines of Lewis's argument, one devoted to what I call the standard GRW interpretation and the other to the mass density interpretation (MDI). I present both strains of Lewis's argument, and move on to criticise Lewis's position, focusing on his argument with respect to MDI. I analyse the structure of his argument, and follow this with a novel refutation of Lewis's argument, drawing on the original presentation of MDI as developed by Ghirardi et al. (Found. Phys. 25 (1995) 5). I briefly consider the debate that ensued between Bassi and Ghirardi and Clifton and Monton and interpret it within the context of my analysis. I conclude that Lewis's Counting Anomaly fails to generate a genuine problem.     

Dark matter,the Equivalence Principle and modified gravity

Dark matter (DM) is an essential ingredient of the present Standard Cosmological Model, according to which only 5% of the mass/energy content of our universe is made of ordinary matter. In recent times, it has been argued that certain cases of gravitational lensing represent a new type of evidence for the existence of DM. In a recent paper, Peter Kosso attempts to substantiate that claim. His argument is that, although in such cases DM is only detected by its gravitational effects, gravitational lensing is a direct consequence of Einstein's Equivalence Principle (EEP) and therefore the complete gravitational theory is not needed in order to derive such lensing effects. In this paper I critically examine Kosso's argument: I confront the notion of empirical evidence involved in the discussion and argue that EEP does not have enough power by itself to sustain the claim that gravitational lensing in the Bullet Cluster constitutes evidence for the DM Hypothesis. As a consequence of this, it is necessary to examine the details of alternative theories of gravity to decide whether certain empirical situations are indeed evidence for the existence of DM. It may well be correct that gravitational lensing does constitute evidence for the DM Hypothesis—at present it is controversial whether the proposed modifications of gravitation all need DM to account for the phenomenon of gravitational lensing and if so, of which kind—but this will not be a direct consequence of EEP.     

Physics,metaphysics, dispositions,and symmetries – À la French

Recent philosophy has paid increasing attention to the nature of the relationship between the philosophy of science and metaphysics. In The Structure of the World: Metaphysics and Representation, Steven French offers many insights into this relationship (primarily) in the context of fundamental physics, and claims that a specific, structuralist conception of the ontology of the world exemplifies an optimal understanding of it. In this paper I contend that his messages regarding how best to think about the relationship are mixed, and in tension with one another. The tension is resolvable but at a cost: a weakening of the argument for French's structuralist ontology. I elaborate this claim in a specific case: his assertion of the superiority of a structuralist account of de re modality in terms of realism about laws and symmetries (conceived ontologically) over an account in terms of realism about dispositional properties. I suggest that these two accounts stem from different stances regarding how to theorize about scientific ontology, each of which is motivated by important aspects of physics.