I argue for accepting a pluralist approach to species, while rejecting the realism about species espoused by P. Kitcher and a number of other philosophers of biology. I develop an alternative view of species concepts as divisions of organisms into groups for study which are relative to the systematic explanatory interests of biologists at a particular time. I also show how this conception resolves a number of difficult puzzles which plague the application of particular species concepts.

I respond to H. M. Collins's claim (1985, 1990, 1993) that experimental inquiry cannot be objective because the only criterium experimentalists have for determining whether a technique is “working” is the production of “correct” (i.e., the expected) data. Collins claims that the “experimenters' regress,” the name he gives to this data-technique circle, cannot be broken using the resources of experiment alone. I argue that the data-technique circle, can be broken even though any interpretation of the raw data produced by techniques is theory-dependent. However, it is possible to break this circle by eliminating dependence on even those theoretical presuppositions that are shared by an entire scientific community through the use of multiple independently theory-dependent techniques to produce robust bodies of data. Moreover, I argue, that it is the production of robust bodies of data that convinces experimentalists of the objectivity of their data interpretations.

With some regularity, cognitive scientists seem to introduce cognitive values into their explanations. After identifying examples of this practice, I sketch an account of psychological explanation that, under certain conditions, legitimizes value-laden cognitive explanations in which evaluative claims appear in the explanandum. I then present and discuss two applications of the proposed account in order to show its viability and explore its consequences.

Information about the prehistoric past is available only in the material remains. To be meaningful, these remains must be interpreted under the influence of a theory of some general or specific aspect of the past. For this reason, prehistoric archaeology clearly shows the reciprocity between theory and evidence and the tension between having to impose information on the evidence in order to discover information in the evidence. We use a specific case in the archaeology of Minoan Crete, a case that uses Central Place Theory as a guide to understanding the evidence, to demonstrate a coherence model of scientific knowledge.

I critically explore various forms of the language of thought (LOT) hypothesis. Many considerations, including the complexity of representational content and the systematicity of language understanding, support the view that some, but not all, of our mental representations occur in a language. I examine several arguments concerning sententialism and the prepositional attitudes, Fodor's arguments concerning infant and animal thought, and Fodor's argument for radical concept nativism and show that none of these considerations require us to postulate a LOT that is innate or otherwise distinct from spoken languages. Instead, I suggest that we maintain the more conservative hypothesis, supported by introspection, that some of our thoughts occur in the languages that we speak.

This paper utilizes the theories of metaphor of George Lakoff, Mark Johnson and Julian Jaynes to extend Jaynes' metaphor theory of consciousness by treating consciousness as an operator that works with ‘covert behavior’ so that humans can integrate temporally discontinuous percepts with concepts based on metaphoric extensions of the embodied schemas of direct and immediate perception and thereby transcend the limitations of direct perception. A theory of first-person expressions and covert behavior to account for self-conscious awareness as language-based is advanced. Subjectivity and objectivity are metaphors based on schemas of perception.

Hacking argues against van Fraassen's constructive empiricism by appeal to features of microscopic imaging. Hacking relies on both our practices involving imaging instruments and the structure of the images produced by these micropractices. Van Fraassen's reply is formally correct yet fundamentally unsatisfying. I aim to strengthen van Fraassen's reply, but must then extend constructive empiricism, specifically the central notion of “theoretical immersion.” I argue that immersion is more analogous to entering a virtual reality than to learning a language. This metaphor assimilates instrument-based practice as well as theoretical debate and explanation, and can provide an anti-realist view of our micro-practices consonant with constructive empiricism.

1. Introduction Dirac's (Dirac 1928) theory of the electron was the first widely accepted relativistic quantum theory, and it later provided the basis for constructing the modern electromagnetic theory of quantum electrodynamics (QED). Whereas Dirac's theory in its simplest form describes relativistic freely-propagating massive non-chiral particles of spin-½, QED describes how such particles interact with one another electromagnetically, via a dynamical quantum field.

Abraham Stone recently has published an argument purporting to show that David Bohm's interpretation of quantum mechanics fails to solve the measurement problem. Stone's analysis is not correct, as he has failed to take account of the conditions under which the theorems he cites are proven. An explicit presentation of a Bohmian measurement illustrates the flaw in his reasoning.

Recently something close to a consensus about the best way to naturalize the notion of biological function appears to be emerging. Nonetheless, teleological notions in biology remain controversial. In this paper we provide a naturalistic analysis for the notion of natural design. Many authors assume that natural design should be assimilated directly to function. Others find the notion problematic because it suggests that evolution is a directed process. We argue that both of these views are mistaken. Our naturalistic account does not simply equate design with function. We argue that the distinction between function and design is important for understanding the evolution of the physical and behavioral traits of organisms.

One of the motivations for Salmon's (1984) causal theory of explanation was the explanatory irrelevance exhibited by many arguments conforming to Hempel's covering-law models of explanation. However, the nexus of causal processes and interactions characterized by Salmon is not rich enough to supply the necessary conception of explanatory relevance. Salmon's (1994) revised theory, which is briefly criticized on independent grounds, fares no better. There is some possibility that the two-tiered structure of explanation described by Salmon (1984) may be pressed into service, but more work would have to be done. Ironically, Salmon's difficulties are similar to those suffered by his seventeenth-century predecessors.

A common methodological adage holds that diverse evidence better confirms a hypothesis than does the same amount of similar evidence. Proponents of Bayesian approaches to scientific reasoning such as Horwich, Howson and Urbach, and Earman claim to offer both a precise rendering of this maxim in probabilistic terms and an explanation of why the maxim should be part of the methodological canon of good science. This paper contends that these claims are mistaken and that, at best, Bayesian accounts of diverse evidence are crucially incomplete. This failure should lend renewed force to a long-neglected global worry about Bayesian approaches.

Quantum mechanics has sometimes been taken to be an empiricist (vs. realist) theory. I state the empiricist's argument, then outline a recently noticed type of measurement—protective measurement—that affords a good reply for the realist. This paper is a reply to scientific empiricism (about quantum mechanics), but is neither a refutation of that position, nor an argument in favor of scientific realism. Rather, my aim is to place realism and empiricism on an even score in regards to quantum theory.

In a recent paper (1994) Wesley Salmon has replied to criticisms (e.g., Dowe 1992c, Kitcher 1989) of his (1984) theory of causality, and has offered a revised theory which, he argues, is not open to those criticisms. The key change concerns the characterization of causal processes, where Salmon has traded “the capacity for mark transmission” for “the transmission of an invariant quantity.” Salmon argues against the view presented in Dowe (1992c), namely that the concept of “possession of a conserved quantity” is sufficient to account for the difference between causal and pseudo processes. Here that view is defended, and important questions are raised about the notion of transmission and about gerrymandered aggregates.

Averill (1990) argues that not every property is a disposition. I claim here that his reasoning is faulty, suffering at one point from a logical error and at other points from an inadequate account of counterfactuals.