At the center of quantum chaos research is a particular family of models known as quantum maps. These maps illustrate an important “horizontal” dimension to model construction that has been overlooked in the literature on models. Three ways in which quantum maps are being used to clarify the relationship between classical and quantum mechanics are examined. This study suggests that horizontal models may provide a new and fruitful framework for exploring intertheoretic relations.

The following analysis shows how developments in epistemic logic can play a nontrivial role in cognitive neuroscience. We argue that the striking correspondence between two modes of identification, as distinguished in the epistemic context, and two cognitive systems distinguished by neuroscientific investigation of the visual system (the “where” and “what” systems) is not coincidental, and that it can play a clarificatory role at the most fundamental levels of neuroscientific theory.

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.

Philosophers of chemistry, following the lead of physicists, have been slow to realize that molecular descriptions issuing from quantum mechanics in the absence of chemical theory are fatally flawed. In the wake of this realization, new topics have begun to unfold—including new metaphysical issues, new concerns about the philosophy of chemistry's place in the philosophy of science, and new accounts of how properties are observed, inferred, and presented. A recent collection of essays, Of Minds and Molecules: New Philosophical Perspectives on Chemistry edited by Nalini Bhushan and Stuart Rosenfeld, reveals what some of these new issues are and suggests new directions for the philosophy of chemistry.

I examine the central theoretical construct of ecological psychology, the concept of an affordance. In the first part of the paper, I illustrate the role affordances play in Gibson's theory of perception. In the second part, I argue that affordances are to be understood as dispositional properties, and explain what I take to be their characteristic background circumstances, triggering circumstances and manifestations. The main purpose of my analysis is to give affordances a theoretical identity enriched by Gibson's visionary insight, but independent of the most controversial claims of the Gibsonian movement.

I present a response to Vollmer's review of the book Of Minds and Molecules, and especially her comments on my own article therein. This provides an opportunity to discuss two central ideas in the philosophy of chemistry. These are the distinction between elements as simple substances (element-1) and elements as basic substances (element-2) and Paneth's proposed intermediate position for philosophy of chemistry. The response also discusses the question of isotopes in relationship to the nature of the elements and their classification as well as the philosophical status of atomic orbitals.

This paper examines the relationship between simulation and experiment. Many discussions of simulation, and indeed the term “numerical experiments,” invoke a strong metaphor of experimentation. On the other hand, many simulations begin as attempts to apply scientific theories. This has lead many to characterize simulation as lying between theory and experiment. The aim of the paper is to try to reconcile these two points of view—to understand what methodological and epistemological features simulation has in common with experimentation, while at the same time keeping a keen eye on simulation's ancestry as a form of scientific theorizing. In so doing, it seeks to apply some of the insights of recent work on the philosophy of experiment to an aspect of theorizing that is of growing philosophical interest: the construction of local models.

In this paper I examine a cognitive mechanism of incommensurability. Using the frame model of concept representation to capture structural relations within concepts, I reveal an ontological difference between object and event concepts: the former are spatial but the latter temporal. Experiments from cognitive sciences further demonstrate that the mind treats object and event concepts differently. Thus, incommensurability can occur in conceptual change across different ontological categories. I use a historical case to illustrate how the ontological difference between an object and an event concept actually caused incommensurability in the context of nineteenth-century optics. The cognitive and historical analyses indicate that incommensurability can be a local phenomenon and does not necessarily imply incomparability.

Science Bought and Sold collects a large portion of the most relevant works on the ‘economics of scientific knowledge production,’ as well as other more recent and unpublished papers on the topic, and the long introductory essay by the editors is an illuminating guide to the field. In this critical notice, I argue that economic theorising about scientific research is providing a peaceful meeting point for many of the combatants in the ‘science wars,’ one from which both epistemic and political questions about science can be more rationally set forth.

A Bayesian account of the virtue of unification is given. On this account, the ability of a theory to unify disparate phenomena consists in the ability of the theory to render such phenomena informationally relevant to each other. It is shown that such ability contributes to the evidential support of the theory, and hence that preference for theories that unify the phenomena need not, on a Bayesian account, be built into the prior probabilities of theories.

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.

How does a complex organism develop from a relatively simple, homogeneous mass? The usual answer is: through the (context-dependent) execution of species-specific genetic instructions specifying the development of that organism. Commentators are sometimes skeptical of this usual answer, but of course not all commentators, and not always for the same reasons. Here I attempt to lay bare the logical structure of the usual answer through an extended analysis of the heuristics and methodological principles at play in the exploration and explanation of development—and also to show a critical ambiguity that renders the usual answer suspect.

At least below the level of species, biological populations are not mind-independent objects that scientists discover. Rather, biological populations are pragmatically constructed as objects of investigation according to the aims, interests, and values that inform particular research contexts. The relations among organisms that are constitutive of population-level phenomena (e.g., mating propensity, genealogy, and competition) occur as matters of degree and so give rise to statistically defined open-ended biological systems. These systems are rendered discrete units to satisfy practical needs and theoretical preferences associated with specific contexts of investigation. While it may be possible to defend a realist position regarding biological relations among organisms, biological populations are “made” when contextual features determine which kinds and degrees of relations to privilege over others, and so how to bound genes in space and time. Consequently, the objectivity of population-based approaches to species genome diversity cannot rest in the mind-independence of populations themselves.

It is proposed that the recent controversy over “time-symmetric quantum counterfactuals” (TSQCs), based on the Aharonov-Bergmann-Lebowitz Rule for measurements of pre- and post-selected systems, can be clarified by taking TSQCs to be counterfactuals with a specific type of compound antecedent. In that case, inconsistency proofs such as that of Sharp and Shanks (1993) are not applicable, and the main issue becomes not whether such statements are true, but whether they are nontrivial. The latter question is addressed and answered in the negative. Thus it is concluded that TSQCs, understood as counterfactuals with a compound antecedent, are true but only trivially so, and provide no new contingent information about specific quantum systems (except in special cases already identified in literature).

It has been argued, most trenchantly by Nancy Cartwright, that the diversity of the concepts and regularities we actually use to describe nature and predict and explain its behavior leaves us with no reason to believe that our foundational physical theories actually “apply” outside of delicately contrived systems within the laboratory. This paper argues that, diversity of method notwithstanding, there is indeed good reason to think that the foundational laws of physics are universal in their scope.