Alan Garfinkel (1981) and Bas van Fraassen (1980), among others, have proposed a contrastive theory of explanation, according to which the proper form of an explanatory why-question is not simply “Why P?” but “Why P rather than Q?”. Dennis Temple (1988) has argued in this journal that the contrastive explanandum “P rather than Q” is equivalent to the conjunction, “P and not-Q”. I show that the contrast is not equivalent to the conjunction, nor to other plausible noncontrastive candidates. I then consider David Lewis's (1986) proposal for the way contrasts determine an explanatory cause, which does not require recasting the contrastive explanandum. Lewis's proposal is found to be unacceptable, but it suggests an improvement that shows contrastive explanations to employ a mechanism of “causal triangulation”, similar to Mill's method of difference.

The alleged problem of “incommensurability” is examined, and attempts to explain scientific change in terms of concepts of meaning and reference are analyzed and rejected. A way of understanding scientific change through a properly developed concept of “reasons” is presented, and the issues of reasons, meaning, and reference are placed in the context of this broader interpretation of scientific change.

In the context of a discussion of time symmetry in the quantum mechanical measurement process, Aharonov et al. (1964) derived an expression concerning probabilities for the outcomes of measurements conducted on systems which have been pre- and postselected on the basis of both preceding and succeeding measurements. Recent literature has claimed that a resulting “time-symmetrized” interpretation of quantum mechanics has significant implications for some basic issues, such as contextuality and determinateness, in elementary, nonrelativistic quantum mechanics. Bub and Brown (1986) have shown that under the standard interpretation of the aforementioned expression, these claims employ ensembles which are not well defined. It is argued here that under a counterfactual interpretation of the expression, these claims may be understood as employing well-defined ensembles; it is shown, however, that such an interpretation cannot be reconciled with the standard interpretation of quantum mechanics.

Starting from the standard quantum formalism for a single spin$\frac{1}{2}$ system (e.g., an electron), this essay develops a model rich enough not only to afford an explication of symmetry breaking but also to frame questions about how to circumscribe physical possibility on behalf of theories that countenance symmetry breaking.

Natural kinds are often contrasted with other kinds of scientific kinds, especially functional kinds, because of a presumed categorical difference in explanatory value: supposedly, natural kinds can ground explanations, while other kinds of kinds cannot. I argue against this view of natural kinds by examining a particular type of explanation—mechanistic explanation—and showing that functional kinds do the same work there as traditionally recognized natural kinds are supposed to do in “standard” scientific explanations. Breaking down this categorical distinction between traditional natural kinds and other kinds of kinds, I argue, delivers two goods: It provides us with a view of natural kindhood that does justice to the epistemic roles of kinds in scientific explanations. And it allows us to solve a problem that HPC theory, currently one of the more popular accounts of natural kindhood, confronts.

A scientific theory offers models for the phenomena in its domain; these models involve theoretical quantities, and a model's structure is the set of relations it imposes on these quantities. A fundamental demand in scientific practice is for those quantities to be clearly and feasibly related to measurement. This demand for empirical grounding can be articulated by displaying the theory-dependent criteria for a procedure to count as a measurement and for identifying the quantity it measures.

The aim of this article is to develop an argument against metaphysical debates about the existence of human races. I argue that the ontology of race is underdetermined by both empirical and nonempirical evidence owing to a plurality of equally permissible candidate meanings of “race.” Furthermore, I argue that this underdetermination leads to a deflationist diagnosis according to which disputes about the existence of human races are nonsubstantive verbal disputes. While this diagnosis resembles general deflationist strategies in contemporary metaphysics, I show that my argument does not presuppose controversial metametaphysical assumptions.

In this article, I first outline the view developed in my recent book on the role of idealization in scientific understanding. I discuss how this view leads to the recognition of a number of kinds of variability among scientific representations, including variability introduced by the many different aims of scientific projects. I then argue that the role of idealization in securing understanding distances understanding from truth but that this understanding nonetheless gives rise to scientific knowledge. This discussion will clarify how my view relates to three other recent books on understanding by Henk de Regt, Catherine Elgin, and Kareem Khalifa.

Standard philosophical discussions of theory-ladeness assume that observational evidence consists of perceptual outputs (or reports of such outputs) that are sentential or propositional in structure. Theory-ladeness is conceptualized as having to do with logical or semantical relationships between such outputs or reports and background theories held by observers. Using the recent debate between Fodor and Churchland as a point of departure, we propose an alternative picture in which much of what serves as evidence in science is not perceptual outputs or reports of such outputs and is not sentential in structure.

This paper utilizes Scott domains (continuous lattices) to provide a mathematical model for the use of idealized and approximately true data in the testing of scientific theories. Key episodes from the history of science can be understood in terms of this model as attempts to demonstrate that theories are monotonic, that is, yield better predictions when fed better or more realistic data. However, as we show, monotonicity and truth of theories are independent notions. A formal description is given of the pragmatic virtues of theories which are monotonic. We also introduce the stronger concept of continuity and show how it relates to the finite nature of scientific computations. Finally, we show that the space of theories also has the structure of a Scott domain. This result provides an analysis of how one theory can be said to approximate another.

Sewall Wright and Gustave Malécot developed important theories of isolation by distance. Wright's theory was statistical and Malécot's probabilistic. Because of this mathematical difference, they were not clear about the relationship between their theories. In this paper, I make two points to clarify this relationship. First, I argue that Wright's theory concerns what I call ecological isolation by distance, whereas Malécot's concerns what I call genetic isolation by distance. Second, I suggest that if Wright's theory is interpreted appropriately, a previously unnoticed connection between the two theories emerges.

Providing a precise statement of their position has long been a central challenge facing scientific realists. This article draws some morals about how realism ought to be formulated from the renormalization group framework in high-energy physics.

Culp (1994) provides a defense for a form of experimental reasoning entitled ‘robustness’. Her strategy is to examine a recent episode in experimental microbiology—the case of the mistaken discovery of a bacterial organelle called a ‘mesosome’—with an eye to showing how experimenters effectively used robust experimental reasoning (or could have used robust reasoning) to refute the existence of the mesosome. My plan is to criticize Culp's assessment of the mesosome episode and to cast doubt on the epistemic significance of robustness. In turn, I present a different account of the experimental reasoning microbiologists used in arriving at the conclusion that mesosomes are artifacts. I call this form of reasoning ‘reliable process reasoning’, and close the paper with a brief discussion of how experimental microbiologists justify the claim that an experimental process is reliable.

This paper makes explicit and takes issue with the bizarre view, which is unfortunately prevalent among social scientists, that causal relations are features of models only. There are some good reasons to represent causal factors with independent variables. But the association between causes and independent variables is only a desideratum in model construction. It is not a criterion for judging which things are causes and which are effects.

Since the appearance of T. S. Kuhn's The Structure of Scientific Revolutions, scholars from various fields have sought to evaluate their disciplines in the light of Kuhnian criteria for scientific change. In this paper I argue that a new paradigm seems needed in high energy physics, and that there is no more reason to say that matter is made of elementary particles, than to say that it is not.

My argument, that high energy physics is approaching a state of crisis, and that a new paradigm is needed, is based on an examination of two events which, according to Kuhn, presage a conceptual revolution: (1) the “old” paradigm of normal science becomes unclear; and (2) this paradigm fails to support normal problem solving research, and scientists begin to use it as if it were merely definitional. After examining the elementary particles paradigm in the light of these two criteria, I conclude that high energy physics is moving from “normal science” to “extraordinary science.” I argue neither that a new paradigm has been found, nor that a return to normal science is imminent; instead I attempt to briefly outline some of the conceptual problems in high energy physics to which Heisenberg, Feynman, and others have alluded, but which so far have not been spelled out in any great philosophical detail. No attempt is made to argue about what the specific consequences of these difficulties might be, but merely to begin to clarify the problems facing scientists dealing with elementary particles.

The subject of this essay is the dependence of evidential relations on background beliefs and assumptions. In Part I, two ways in which the relation between evidence and hypothesis is dependent on such assumptions are discussed and it is shown how in the context of appropriately differing background beliefs what is identifiable as the same state of affairs can be taken as evidence for conflicting hypotheses. The dependence of evidential relations on background beliefs is illustrated by discussions of the Michelson-Morley experiment and the discovery of oxygen. In Part II, Hempel's analysis of confirmation and the contrasting model of theory acceptance provided by philosophers such as Kuhn and Feyerabend are discussed. It is argued that both are inadequate (on different grounds) and the problems addressed by each are shown to be more satisfactorily approached by means of the analysis developed in Part I. In Part III, it is argued that if there are objective criteria for deciding between competing theories, these cannot be simply that one theory has greater evidential support than another. Finally, some further methodological questions arising from the analysis are mentioned.

This article examines two cosmological models of quantum gravity (from string theory and loop quantum gravity) to investigate the foundational and conceptual issues arising from quantum treatments of the big bang. While the classical singularity is erased, the quantum evolution that replaces it may not correspond to classical spacetime: it may instead be a nonspatiotemporal region that somehow transitions to a spatiotemporal state. The different kinds of transition involved are partially characterized, the concept of a physical transition without time is investigated, and the problem of empirical incoherence for regions without spacetime is discussed.

We here present explicit relational theories of a class of geometrical systems (namely, inner product spaces) which includes Euclidean space and Minkowski spacetime. Using an embedding approach suggested by the theory of measurement, we prove formally that our theories express the entire empirical content of the corresponding geometric theory in terms of empirical relations among a finite set of elements (idealized point-particles or events) thought of as embedded in the space. This result is of interest within the general phenomenalist tradition as well as the theory of space and time, since it seems to be the first example of an explicit phenomenalist reconstruction of a realist theory which is provably equivalent to it in observational consequences.

The interesting paper “On the Space-Time Ontology of Physical Theories” by Ken Manders, Philosophy of Science, vol. 49, number 4, December 1982, p. 575–590, has significant affinities to this one. We both, in a sense, try to formally vindicate Leibniz's notion of a relational theory of space, by constructing theories of spatial relations among physical objects which are provably equivalent to the standard absolutist theories. The essential difference between our approaches is that Manders retains Leibniz's explicitly modal framework, whereas I do not. Manders constructs a spacetime theory which explicitly characterizes the totality of possible configurations of physical objects, using a modal language in which the notion of a possible configuration occurs as a primitive. There is no doubt that this is a more accurate realization of Leibniz's own conception of space than the embedding-based approach developed here. However, it also remains open to objections (such as those cited here from Sklar) on account of the special appeal to modal notions.

Our approach here, by contrast, aims to avoid the special appeal to modal notions by giving directly a set of laws which are satisfied by a configuration individually, if and only if it is one of the allowable ones. One thus avoids the need for reference to possible but not actual configurations or objects, in the statement of the spacetime laws. We may then take this alternative set of laws as the actual geometric theory, and do away with the hypothetical entity called ‘space'. Yet at the same time there is no invocation of modality, except in the ordinary sense in which every physical theory constrains what is possible. So that a relationalist is not forced to utilize a modal language (though Leibniz certainly does.)

This paper tries to get a grip on two seemingly conflicting intuitions about reductionism in quantum mechanics. On one hand it is received wisdom that quantum mechanics puts an end to ‘reductionism’. Quantum entanglement is responsible for such features of quantum mechanics as holism, the failure of supervenience, and emergence. While I agree with these claims, I will argue that it is only part of the story. Quantum mechanics provides us with thoroughgoing reductionist explanations. I will distinguish two kinds of microexplanation (or micro-‘reduction’). I will argue that even though quantum entanglement provides an example of the failure of one kind of microexplanation, it does not affect the other. Contrary to a recent paper by Kronz and Tiehen, I claim that the explanation of the dynamics of quantum mechanical systems is just as reductionist as it used to be in classical mechanics.

In game-theoretic signaling models, evolution tends to favor perfectly precise signaling systems, but in the natural world communication is almost always imprecise. I argue that standard explanations for this discrepancy are only partially sufficient, and I show that communication is often ambiguous because signal senders take advantage of context sensitivity. As evidence, I make two additions to the signaling model: a cost for more complex signaling strategies and the ability to combine information in signals with independent information. Analysis and simulation of the altered model shows that it leads to the predicted outcome of evolution favoring ambiguous signaling.