In this paper, I discuss the key role played by Carl G. Hempel's work on theoretical realism and scientific explanation in effecting a crucial philosophical transition between the beginning and the end of the twentieth century. At the beginning of the century, the dominant view was that science is incapable of furnishing explanations of natural phenomena; at the end, explanation is widely viewed as an important, if not the primary, goal of science. In addition to its intellectual benefits, this transition has important practical consequences with respect to dealing with the global problems humans everywhere will face in the twenty-first century.

Inflationary cosmology won a large following on the basis of the claim that it solves various problems that beset the standard big bang model. We argue that these problems concern not the empirical adequacy of the standard model but rather the nature of the explanations it offers. Furthermore, inflationary cosmology has not been able to deliver on its proposed solutions without offering models which are increasingly complicated and contrived, which depart more and more from the standard model it was supposed to improve upon, and which sever the connection between cosmology and particle physics that initially made the inflationary paradigm so attractive. Nevertheless, inflationary cosmology remains a promising research program, not least because it offers an explanation of the origin of the density perturbations that seeded the formation of galaxies and other cosmic structures. Tests of this explanation are underway and may settle the issue of whether inflation played an important role in the early universe.

Leeds (1990) levels an objection against the criterion of rational choice I have proposed (Levi 1997, Ch. 6; 1980; 1986), pointing out that the criterion is sensitive to the way possible consequences are partitioned. Seidenfeld, Kadane and Schervish (1989) call into question the defense of the cross product rule by appeal to Pareto Unanimity Principles that I had invoked in my 1986. I offer clarifications of my proposals showing that the difference between my views and those of my critics concerns the extent to which full belief, probabilistic belief, and value judgment are separable.

The contention that psychological states are multiply realizable in different substrates has been used to support the contention that neuroscience is not likely to be very useful in guiding an understanding how cognition works. But in the context of scientific research, how seriously should we really take this threat of multiple realizability? By examining how brain areas are identified in neuroscience (where the approach is comparative and employs functional criteria), we show that the skepticism about neuroscience's role in understanding cognition is misguided and that the apparent success of multiple realizability is based on methodological error. With respect to the former point, we develop and analyze a representative case in which the organization of the brain provides crucial information about the organization of the cognitive system. Then we show that the initial plausibility of claims to multiple realizability rest on (a) mismatching a broad-grained criterion (to show sameness of psychological states) with a finegrained criterion (to differentiate brain states), and (b) a failure to attend to the purposes for which taxonomies of brain and psychological states are developed.

Much of the current thought concerning mathematical ontology and epistemology follows Quine and Putnam in looking to the indispensable application of mathematics in science. A standard assumption of the indispensability approach is some version of confirmational holism, i.e., that only “sufficiently large” sets of beliefs “face the tribunal of experience.” In this paper I develop and defend a distinction between a pure mathematical theory and a mathematized scientific theory in which it is applied. This distinction allows for the possibility that pure mathematical theories are systematically insulated from such confirmation in virtue of their being distinct from the “sufficiently large” blocks of scientific theory that are empirically confirmed.

Hempel's paradox of the ravens arises from the inconsistency of three prima facie plausible principles of confirmation. This paper uses Camapian inductive logic to (a) identify which of the principles is false, (b) give insight into why this principle is false, and (c) identify a true principle that is sufficiently similar to the false one that failure to distinguish the two might explain why the false principle is prima facie plausible. This solution to the paradox is compared with a variety of other responses and is shown to differ from all of them.

The Hard Problem of the mind is addressed and it is argued that physical-phenomenal property identities have the same status as the identification of an ostended bit of physical space and the coordinates assigned the spot on a map of the terrain. It is argued, that is to say, that such identities are, or follow from, stipulations which interpret the map.

Are thought experiments nothing but arguments? I argue that it is not possible to make sense of the historical trajectory of certain thought experiments if one takes them to be arguments. Einstein and Bohr disagreed about the outcome of the clock-in-the-box thought experiment, and so they reconstructed it using different arguments. This is to be expected whenever scientists disagree about a thought experiment's outcome. Since any such episode consists of two arguments but just one thought experiment, the thought experiment cannot be the arguments.

David Malament's (1977) well-known result, which is often taken to show the uniqueness of the Poincaré-Einstein convention for defining simultaneity, involves an unwarranted physical assumption: that any simultaneity relation must remain invariant under temporal reflections. Once that assumption is removed, his other criteria for defining simultaneity are also satisfied by membership in the same backward (forward) null cone of the family of such cones with vertices on an inertial path. What is then unique about the Poincaré-Einstein convention is that it is independent of the choice of inertial path in a given inertial frame, confirming a remark in Einstein 1905. Similarly, what is unique about the backward (forward) null cone definition is that it is independent of the state of motion of an observer at a point on the inertial path.

In this paper I argue that category theory ought to be seen as providing the language for mathematical discourse. Against foundational approaches, I argue that there is no need to reduce either the content or structure of mathematical concepts and theories to the constituents of either the universe of sets or the category of categories. I assign category theory the role of organizing what we say about the content and structure of both mathematical concepts and theories. Insofar, then, as the structuralist sees mathematics as talking about structures and their morphology, I contend that category theory furnishes a framework for mathematical structuralism.

I present an attempt at an explication of the ecological theory of interspecific competition, including its explanatory role in community ecology and evolutionary biology. The account given is based on the idea that law-like statements play an important role in scientific theories of this kind. I suggest that the principle of competitive exclusion is such a law, and that it is evolutionary invariant. The principle's empirical status is defended and implications for the ongoing debates on the existence of biological laws are discussed.

Reductionism is often understood to include two theses: (1) every singular occurrence that the special sciences can explain also can be explained by physics; (2) every law in a higher-level science can be explained by physics. These claims are widely supposed to have been refuted by the multiple realizability argument, formulated by Putnam (1967, 1975) and Fodor (1968, 1975). The present paper criticizes the argument and identifies a reductionistic thesis that follows from one of the argument's premises.

According to the traditional presentation of Bohm's interpretation, we have immediate epistemic access to particle properties but not wavefunction properties, and mental states, pointer states, and ink patterns supervene on particle properties alone. I argue that these claims do not make physical sense, and I offer an alternative account that does.

In his book, The Conscious Mind, David Chalmers argues that his theory of consciousness can lend support to the Everett “no collapse” interpretation of quantum mechanics. We argue that Chalmers's argument fails, and that any Everett-style interpretation should be rejected.

Mark Wilson, in his 1985 paper entitled “What Is This Thing Called ‘Pain‘?: The Philosophy of Science Behind the Contemporary Debate,” proposed an account of physicalism that departs significantly from standard approaches. One of the main points of his paper was to explain the flaws in arguments claiming that psychological properties cannot be shown to be physical because of their functional nature. However, the positive proposal that Wilson makes in this article bears further examination. I argue that it not only resolves many problems that have grown up around the topic of physicalism, but that the proposal itself should make us radically rethink some important philosophical questions, especially those concerning explanation and property identification.

I identify the special sort of stability (invariance, resilience, etc.) that distinguishes laws from accidental truths. Although an accident can have a certain invariance under counterfactual suppositions, there is no continuum between laws and accidents here; a law's invariance is different in kind, not in degree, from an accident's. (In particular, a law's range of invariance is not “broader”—at least in the most straightforward sense.) The stability distinctive of the laws is used to explicate what it would mean for there to be multiple grades (or degrees) of physical necessity. Whether there are is for science to discover.

In this paper I assess Gopnik and Meltzoff's developmental psychology of science as a contribution to the understanding of scientific development. I focus on two specific aspects of Gopnik and Meltzoff's approach: the relation between their views and recapitulationist views of ontogeny and phylogeny in biology, and their overall conception of cognition as a set of veridical processes. First, I discuss several issues that arise from their appeal to evolutionary biology, focusing specifically on the role of distinctions between ontogeny and phylogeny when appealing to biology for theoretical support. Second, I argue that to presuppose that cognition is veridical or “truth-tropic” can compromise attempts to understand scientific cognition both throughout history and in the present. Finally, I briefly sketch an evolutionary approach to understanding scientific development that contrasts with Gopnik and Meltzoff's.

We first examine Howard's analysis of the Bell factorizability condition in terms of ‘separability’ and ‘locality’ and then consider his claims that the violations of Bell's inequality by the statistical predictions of quantum mechanics should be interpreted in terms of ‘nonseparability’ rather than ‘nonlocality’ and that ‘nonseparability’ implies the failure of spacetime as a principle of individuation for quantum-mechanical systems. We will argue that his argument for the first claim is less than compelling and that any argument for the second claim will be interpretation-dependent and, hence, not generally valid.

Brian Skyrms has studied the evolutionary dynamics of a simple bargaining game. Fair-dealing is the strategy ’demand 1/2’, competing with the more modest strategy ‘demand 1/3’ and the greedier strategy ‘demand 2/3’. Individuals leave offspring in proportion to their accumulated payoffs. The rules for payoffs from encounters penalize low- and high-demanders. The result is a significant basin of attraction for fair-dealing as an evolutionarily stable strategy. From these considerations Skyrms concludes that a disposition to fair-dealing could have evolved. A very different picture emerges, however, when one considers genetic bases for the dispositions involved. A simple two-allele sexual model produces very different stable equilibria in the distribution of behavioral phenotypes. The equilibria for Skyrms's purely phenotypic selection process will not in general be attainable once one enters some simple genetic considerations.