There are few, perhaps no known, exact, true, general laws. Some of the work of generalization is carried by ceteris paribus generalizations. I suggest that many models continue such work in more complex form, with the idea of ceteris paribus conditions thought of as extended to more general conditions of application. I use the term regularity guide to refer collectively to cp-generalizations and such regularity-purveying models. Laws in the traditional sense can then be thought of as idealizations, which idealize away from the conditions of application of regularity guides. If we keep clearly in mind the status of laws as such idealizations, problems surrounding traditional topics—such as lawlikeness, corresponding counterfactuals and modality—no longer look to be intractable.

After precisely specifying the thesis of the causal theory of time, Grünbaum's program developed to support this thesis is examined. Four objections to his definition of temporal order in terms of a more primitive causal relation are put and held to be conclusive. Finally, the philosophical arguments that Grünbaum has proposed supporting the desirability of establishing a causal theory of time are shown to be either invalid or inconclusive.

1. Terminological Considerations. Since Russell enunciated the principle, “Wherever possible logical constructions are to be substituted for inferred entities,” or “Wherever possible, substitute constructions out of known entities for inferences to unknown entities,” the terminological situation has become confused. Russell defined neither “construction” nor “inferred entity.” “Construct” soon came to be used for “construction,” perhaps to avoid the ambiguity whereby the latter term was used to refer to both a process and a result. But many writers now use “construction” or “construct” to refer to what Russell called the “inferred entity.” This seems to be the usage of Margenau, Ramsperger, Benjamin, Bures, and many others. Again, some of the same writers in other places (e.g., Benjamin) remain closer to Russell's usage. And I find it difficult to determine exactly the relation of the usage of some writers to that of Russell because of the differences between their contexts and Russell's. I experience this difficulty in reading, for instance, both Miss Stebbing and Werkmeister. The terminological difficulties have been evaded by some other writers who have formulated new terms to refer to Russell's inferred entities. Thus Northrop speaks of the “theoretic component” and Miller has coined the word, “interphenomena.” The terms reflecting Russell's rule in psychology have become so confused that a set of explicit definitions has recently been proposed.

In “Concepts Are Not a Natural Kind” (2005), I argued that the notion of concept in psychology and in neuropsychology fails to pick out a natural kind. Piccinini and Scott (2006, in this issue) have criticized the argument I used to support this conclusion. They also proposed two alternative arguments for a similar conclusion. In this reply, I rebut Piccinini and Scott's main objection against the argument proposed in “Concepts Are Not a Natural Kind.” Moreover, I show that the two alternative arguments developed by Piccinini and Scott are not promising for supporting the conclusion that concepts are not a natural kind.

This essay considers the nature of conceptual frameworks in science, and suggests a reconsideration of the role played by philosophy in radical conceptual change. On Kuhn's view of conceptual conflict, the scientist's appeal to philosophical principles is an obvious symptom of incommensurability; philosophical preferences are merely “subjective factors” that play a part in the “necessarily circular” arguments that scientists offer for their own conceptual commitments. Recent work by Friedman has persuasively challenged this view, revealing the roles that philosophical concerns have played in preparing the way for conceptual change, creating an enlarged conceptual space in which alternatives to the prevailing framework become intelligible and can be rationally discussed. If we shift our focus from philosophical themes or preferences to the process of philosophical analysis, however, we can see philosophy in a different and much more significant historic role: not merely as an external source of general heuristic principles and new conceptual possibilities, but, at least in the most important revolutionary developments, as an objective tool of scientific inquiry. I suggest that this approach offers some insight into the philosophical significance of Newton's and Einstein's revolutionary work in physics, and of the interpretation of their work by (respectively) Kant and the logical positivists. It also offers insight into the connections between modern philosophy of science and some traditional philosophical concerns about the nature of a priori knowledge.

In this article I connect two debates in the philosophy of science: the questions of scientific representation and both model and theoretical equivalence. I argue that by paying attention to how a model is used to draw inferences about its target system, we can define a notion of theoretical equivalence that turns on whether models license the same claims about the same target systems. I briefly consider the implications of this for two questions that have recently been discussed in the context of the formal philosophy of science.

Using Gebharter’s representation, we consider aspects of the problem of discovering the structure of unmeasured submechanisms when the variables in those submechanisms have not been measured. Exploiting an early insight of Sober’s, we provide a correct algorithm for identifying latent, endogenous structure—submechanisms—for a restricted class of structures. The algorithm can be merged with other methods for discovering causal relations among unmeasured variables, and feedback relations between measured variables and unobserved causes can sometimes be learned.

Fitness is a central theoretical concept in evolutionary theory. Despite its importance, much debate has occurred over how to conceptualize and formalize fitness. One point of debate concerns the roles of organismic and trait fitness. In a recent addition to this debate, Elliott Sober argues that trait fitness is the central fitness concept, and that organismic fitness is of little value. In this paper, by contrast, we argue that it is organismic fitness that lies at the bases of both the conceptual role of fitness and its role as a measure of evolutionary dynamics.

Although cases are central to the epistemic practices utilized within clinical medicine, they appear to be limited in their ability to provide evidence about causal relations because they provide detailed accounts of particular patients without explicit filtering of those attributes most likely to be relevant for explaining the phenomena observed. This paper uses a series of recent case reports to explore the role of cases in causal attribution in medical diagnosis. It is argued that cases are brought together by practitioners to generate causal attributions and testable predictions using a manipulability view of causation.

Scientific realists endeavor to secure inferences from empirical success to approximate truth by arguing that, despite the demise of empirically successful theories, the parts of those theories responsible for their success do, in fact, survive theory change. If, as some antirealists have recently suggested, successful theory parts are only identifiable in retrospect, namely, as those that have survived, then the realist approach is trivialized, for now success and survival are guaranteed to coincide. The primary aim of this article is to counter this argument by identifying successful theory parts independently from their survival.

The dark matter problem in astrophysics exposes an underappreciated weakness in the evidential warrant for General Relativity (GR). The “dark matter double bind” entails that GR gets no differential evidential support from dynamical phenomena occurring at scales larger than our solar system, as compared to members of a significant class of rival gravitation theories. These rivals are each empirically indistinguishable from GR for phenomena taking place at solar system scales, but make predictions that may differ radically from GR's at larger scales. Thus the typical confidence in the universal applicability of GR is insufficiently warranted in the present evidential context.

The attempt to draw a clear distinction between Philosophy and the empirical sciences can almost be taken as the defining trait of the analytic movement in contemporary philosophical thought. The empirical science that has most frequently threatened to swallow up questions of particular interest to philosophers since the time of Descartes has been psychology. Characteristic, then, of analytic philosophy has been the rejection of what it terms psychologism, that is to say, the mistake of identifying philosophical categories with those of psychology, whether introspective or behavioristic. It is clear that to launch an attack on psychologism, thus conceived, presupposes that one has a list of philosophical categories which one is able to identify as such; and this in turn presupposes an ability to sketch, at least in a general way, a distinctly philosophical account of these concepts, although a systematic account along non-psychologistic lines may be a distant and ill-defined goal. The analytic movement in philosophy has gradually moved towards the conclusion that the defining characteristic of philosophical concepts is that they are formal concepts relating to the formation and transformation rules of symbol structures called languages. Philosophy, in other words, tends to be conceived of as the formal theory of languages. From this standpoint, consequently, psychologism is conceived of as the psychological treatment of concepts which are properly understood as formal devices defining a mode of linguistic structure.

The title of this symposium, “Formal Simplicity as a Weight in the Acceptability of Scientific Theories,” to some people might seem to suggest that we are to be making positive proposals about how the concept of simplicity could be defined for formalized languages, defined so as to figure in a formalized theory of confirmation. I must confess at the start that I do not have any such ambitious object in view. I now feel, indeed, that premature formalizations have little power to illuminate the philosophically interesting questions which cluster round the problem of the role of simplicity in scientific thinking. So in this short paper I wish merely to present some elementary considerations, not very novel ones, concerning the role which simplicity seems to me to play in our non-demonstrative reasoning about matters of empirical fact. Although many writers have sought to analyze the logical character of such reasoning, little unanimity has been attained in their over-all views; thus it is that though the considerations which I wish to present are elementary, they are not wholly uncontroversial. But because these matters are elementary in nature, I do feel it appropriate in discussing them to use homely examples of uncomplicated kinds, rather than elaborate examples drawn from the more sophisticated reaches of scientific theory; in doing so, I am taking it for granted that scientific inference as regards its logical character is fundamentally a refinement of everyday thinking, rather than a procedure of some essentially different nature.

Could some evidence confirm a conjunction of two hypotheses more than it confirms either of the hypotheses separately? We show that it might, moreover under conditions that are the same for ten different measures of confirmation. Further, we demonstrate that it is even possible for the conjunction of two disconfirmed hypotheses to be confirmed by the same evidence.

Is there more than one “Curie’s principle”? How far are different formulations legitimate? What are the aspects that make it so scientifically fruitful? This article is devoted to exploring these questions. We begin by discussing Curie’s original 1894 article. Then, we consider the way that the discussion of the principle took shape from early commentators to its modern form. We say why we think that the modern focus on the interstate version of the principle loses sight of some of the most significant applications of the principle. Finally, we address criticisms of the principle put forward by John Norton and Bryan Roberts.

This paper is a discussion of David Albert's approach to the foundations of classical statistical menchanics. I point out a respect in which his account makes a stronger claim about the statistical mechanical probabilities than is usually made, and I suggest what might be motivation for this. I outline a less radical approach, which I attribute to Boltzmann, and I give some reasons for thinking that this approach is all we need, and also the most we are likely to get. The issue between the two accounts turns out to be one about the explanatory role probabilities play in statistical mechanics.

This article examines the role of historical science in clarifying the causal structure of complex natural processes. I reject the pervasive view that historical science does not uncover natural regularities. To show why, I consider an important methodological distinction in geology between uniformitarianism and actualism; methodological actualism, the preferred method of geologists, often relies on historical reconstructions to test the stability of currently observed processes. I provide several case studies that illustrate this, including one that highlights how historical narratives can improve predictive models.

The idea that remembering involves an engram, becoming stable and permanent via consolidation, has guided the neuroscience of memory since its inception. The shift to thinking of memory as continuous and dynamic, as part of a trend toward neural dynamics, has challenged this commitment, with some, such as Lynn Nadel, calling for “the demise of the fixed trace” and others, such as Alcino J. Silva, urging rejection of the “consolidation dogma.” Does consideration of neural dynamics offer reasons to reject engram theory? No. I argue that they are compatible. At most, shifting to a dynamic view of neural processes compels revision of the implementational details.

By reference to Maxwell's kinetic theory, one feature of hypothetico-deductivism is defended. A scientist need make no inference to a hypothesis when he first proposes it. He may have no reason at all for thinking it is true. Yet it may be worth considering. In developing his kinetic theory there were central assumptions Maxwell made (for example, that molecules are spherical, that they exert contact forces, and that their motion is linear) that he had no reason to believe true. In this paper I develop a position that explains why they were worth considering, and that rejects the retroductive position that a hypothesis is worth considering when, if true, it would explain the observed data.