The so-called post-Wittgensteinian Oxford philosophers are often criticized not only for failing to provide for the causal explanation of human behavior and psychological states, but also for failing to recognize that psychological explanations require appeal to sub-personal or molecular processes. Three strategies accommodating this criticism appear in so-called homunculus theories and include: (1) that the sub-systems be assigned intentional or informational content purely heuristically; (2) that the intentional or informational content of molar states be analyzed without remainder in terms of molecular processing; (3) that the entire or salient range of mental or informational molar states be accessible at the molecular level, or vice versa. Option (2) proves to be the most radical and is favored by Dennett. (1) relevantly requires a reduction of the intentional. (3) is illustrated in various ways by the views of Freud, Chomsky, Fodor. (2) is shown to depend on (1) or to be idle; and (3) embraces at least in part an appeal to molar-level explanation. The argument developed attempts to show the sense in which discourse about molar and molecular-level phenomena in the psychological context is fundamentally different from macroscopic and microtheoretical-level discourse about physical phenomena. The conclusion drawn is that neither a molar nor a sub-personal level theory is suitably explanatory in the psychological sense: a psychological theory is committed rather to a set of sub-personal components of such systems, that serve to explain molar phenomena.

This article considers the thesis that a more proportional relationship between a cause and its effect yields a more abstract causal explanation of that effect, thereby producing a deeper explanation. This thesis has important implications for choosing the optimal granularity of explanation for a given explanandum. In this article, I argue that this thesis is not generally true of probabilistic causal relationships. In light of this finding, I propose a pragmatic measure of explanatory depth. This measure uses a decision-theoretic model of information pricing to determine the optimal granularity of explanation for a given explanandum, agent, and decision problem.

Some materialists argue that we can eliminate mental entities such as sensations because, like electrons, they are theoretical entities postulated as parts of scientific explanations, but, unlike electrons, they are unnecessary for such explanations. As Quine says, any explanatory role of mental entities can be played by “correlative physiological states and events instead.” But sensations are not postulated theoretical entities. This is shown by proposing definitions of the related terms, ‘observation term,’ and ‘theoretical term,’ and then classifying the term ‘sensation.’ The result is that although ‘sensation’ is a theoretical term, it is also a reporting term because it is used to refer to phenomena we are aware of. Consequently sensations are not postulated and cannot be eliminated merely because they are unnecessary for explanation.

Is it a “conceptual truth” or only a logically contingent fact that, in any given kind of case, an event x which asymmetrically causes (“produces”) an event y likewise temporally precedes y or at least does not temporally succeed y? A bona fide physical example in which the cause retroproduces the effect would show that backward causation is no less conceptually possible than forward causation. And it has been claimed ([9], p. 151; [4], p. 41) that in Dirac's classical electrodynamics (relativistic and non-relativistic), the preacceleration of charged particles before any forces are applied to them furnishes a genuine case of retrocausation by later forces.

An exposition of the pertinent physics furnishes the basis for arguing the following: Whereas the non-zero acceleration of a neutral NEWTONIAN mass particle is, of course, causally connected as such to the simultaneously applied non-zero force, the non-zero acceleration of a DIRACIAN charged particle is not causally connected at all as such to the applied forces. A fortiori, in Dirac's electrodynamics, the applied forces do not qualify asymmetrically as the causes of a non-zero acceleration as such; nor does a non-zero acceleration as such qualify as an effect produced by forces. This is shown by means of two considerations as follows: (1) In Dirac's theory, no functional dependence of the value of a non-zero acceleration on the weighted time-average of the forces is vouchsafed as a matter of physical LAW alone without any value of a constant of integration, just as no Newtonian law(s) alone can guarantee a functional dependence of the non-zero value of the velocity of a Newtonian mass particle on the applied forces. Instead, both functional dependencies alike are vouchsafed only with the crucial aid of some de facto boundary condition pertaining to either the past or to the future, so that (2) Non-zero preaccelerations of Diracian charged particles can no more be causally attributed as such to the retrocausal action of later forces than non-zero “prevelocities” of Newtonian mass particles can be held to be caused as such by later applied forces. The retrocausal interpretation of Dirac's preaccelerations is just as invalid as the retrocausal interpretation of Newtonian prevelocities.

The conditions are examined under which one theory is said to be replaceable by another, while preserving those features of the original theory which made it serviceable for a given purpose. Among such replacements, special attention is given to ones which qualify as so-called reductions of a theory, and some theorems are proved concerning the notion of a reduction.

This paper uses a number of examples of diverse types and functions of models in evolutionary biology to argue that the demarcation between theory and practice, or “theory model” and “data model,” is often difficult to make. It is shown how both mathematical and laboratory models function as plausibility arguments, existence proofs, and refutations in the investigation of questions about the pattern and process of evolutionary history. I consider the consequences of this for the semantic approach to theories and theory confirmation. The paper attempts to reconcile the insights of both critics and advocates of the semantic approach to theories.

The most recent attempt at factually establishing a “true” value for the oneway velocity of light is shown to be faulty. The proposal consists of two round-trip photons travelling first in vacuo and then through a medium of refractive index n before returning to their common point of origin. It is shown that this proposal, as well as a similar one considered by Salmon (1977), presupposes that the one-way velocities of light are equal to the round-trip value. Furthermore, experiments of this type, involving regions of space with varying refractive indices, cannot “single out” any factual value for the Reichenbach-Grünbaum ∊ factor thus posing no threat to the conventionalist thesis.

The conflation of two fundamentally distinct issues has generated serious confusion in the philosophical and biological literature concerning the units of selection. The question of how a unit of selection of defined, theoretically, is rarely distinguished from the question of how to determine the empirical accuracy of claims—either specific or general—concerning which unit(s) is undergoing selection processes. In this paper, I begin by refining a definition of the unit of selection, first presented in the philosophical literature by William Wimsatt, which is grounded in the structure of natural selection models. I then explore the implications of this structural definition for empirical evaluation of claims about units of selection. I consider criticisms of this view presented by Elliott Sober—criticisms taken by some (for example, Mayo and Gilinsky 1987) to provide definitive damage to the structuralist account. I shall show that Sober has misinterpreted the structuralist views; he knocks down a straw man in order to motivate his own causal account. Furthermore, I shall argue, Sober's causal account is dependent on the structuralist account that he rejects. I conclude by indicating how the refined structural definition can clarify which sorts of empirical evidence could be brought to bear on a controversial case involving units of selection.

One of the issues dividing “absolutists” and “relationists” is the question whether all motion is relative motion or, in the words of Earman, spacetime has “structures that support absolute quantities of motion.” This paper argues that, despite the enormous literature bearing on the topic, it is problematic to formulate a general criterion for when a quantity counts as absolute in contrast to merely relative in a way that is not hopelessly parasitic on other, presumably distinct, senses of “absolute.” Furthermore, I suggest that the vicissitudes of the evolution of the concept of absolute motion have contributed to this difficulty.

Nonreductive physicalists have long used multiple realizability to argue for the explanatory “autonomy” of the special sciences. Recently, in the face of the local reduction and disjunctive property responses to multiple realizability, some defenders of nonreductive physicalism have suggested that autonomy can be grounded merely in human cognitive limitations. In this article, I argue that this is mistaken. By distinguishing between two kinds of abstraction I show that the greater explanatory relevance of some special-science predicates (to certain explananda) is both nonanthropocentric and not solely based on considerations of multiple realizability.

Standard accounts of the micro-reduction of phenomenological to kinetic thermostatics, based on the postulate relating empirical absolute temperature to mean kinetic energy (ū = (3/2)kT), face two problems. The standard postulate also allows ‘reduction’ in the other direction and it can be criticized from the point of view that reduction postulates need to be ontological identities.

This paper presents a detailed account of the reduction, based on the postulate that thermal equilibrium is ontologically identical to having equal mean kinetic energy. In particular, it is shown that this postulate enables reduction only in the appropriate direction, but leaves room for ‘evidence transport’ in the other. Moreover, it makes possible the derivation (explanation) of the standard postulate, using the existential kinetic hypothesis and phenomenological laws with which it turns out to be laden.

Jeffrey has devised a probability revision method that increases the probability of hypothesis H when it is discovered that H implies previously known evidence E. A natural extension of Jeffrey's method likewise increases the probability of H when E has been established with sufficiently high probability and it is then discovered, quite apart from this, that H confers sufficiently higher probability on E than does its logical negation H̄.

Several revisions of the Hempel and Oppenheim definition of explanation have been offered in recent years, and none have gone uncriticized in the literature. In the present paper it is argued that the difficulties involved with these attempts are based upon a confusion between three types of explanation, and that Professor David Kaplan's model of S-explanation provides a uniform treatment of all three types.

The theory of general relativity has produced some great insights into the nature of space and time. Unfortunately, its relevance to the problem of the direction of time has been overestimated. This paper points out that the problem of the direction of time can be formulated in purely local ways, and that in this kind of formulation considerations of general relativity are of little or no importance. On the basis of this, positions which assume that relativistic considerations are always relevant are criticised.

In the nineteenth century, William Whewell claimed that his confirmation criterion of consilience was a truth-guarantor: we could, he believed, be certain that a consilient theory was true. Since that time Whewell has been much ridiculed for this claim by critics such as J. S. Mill and Bas van Fraassen. I have argued elsewhere that, while Whewell's claim that consilience can guarantee the truth of a theory is clearly wrong, consilience is indeed quite useful as a confirmation criterion (Snyder 2005). Here I will show that, even when consilience gives evidence for a theory that turns out to be false, there is an important sense in which consilience shows that the theory has captured something correct about the natural-kind structure of the physical world. Whewell was therefore correct to claim that consilience provides a “criterion of reality” (Whewell [1847] 1967, vol. 2, 68). Consilience provides this by giving justification for the claim that we have really ‘cut nature at its causal joints’, to adapt Plato's famous phrase. Because of this, consilience can play a role in an argument for scientific realism.

General relativity is commonly thought to imply the existence of a unique metric structure for space-time. A simple example is presented of a general relativistic theory with ambiguous metric structure. Brans-Dicke theory is then presented as a further example of a space-time theory in which the metric structure is ambiguous. Other examples of theories with ambiguous metrical structure are mentioned. Finally, it is suggested that several new and interesting philosophical questions arise from the sorts of theories discussed.

Contrary to the assumptions of empiricist philosophies of science, the theory-laden character of data will not imply the inherent failure (subjectivity, circularity, or rationalization) of instruments to expose nature's secrets. The success of instruments is credited to scientists' capacity to create artificial technological analogs to familiar physical systems. The design of absorption spectrometers illustrates the point: Progress in designing many modern instruments is generated by analogically projecting theoretical insights from known physical systems to unknown terrain. An experimental realism is defended.

Schaffner's model of theory reduction has played an important role in philosophy of science and philosophy of biology. Here, the model is found to be problematic because of an internal tension. Indeed, standard antireductionist external criticisms concerning reduction functions and laws in biology do not provide a full picture of the limits of Schaffner's model. However, despite the internal tension, his model usefully highlights the importance of regulative ideals associated with the search for derivational, and embedding, deductive relations among mathematical structures in theoretical biology. A reconstructed Schaffnerian model could therefore shed light on mathematical theory development in the biological sciences and on the epistemology of mathematical practices more generally.

Kinds that share historical properties are dubbed “historical kinds” or “etiological kinds,” and they have some distinctive features. I will try to characterize etiological kinds in general terms and briefly survey some previous philosophical discussions of these kinds. Then I will take a closer look at a few case studies involving different types of etiological kinds. Finally, I will try to understand the rationale for classifying on the basis of etiology, putting forward reasons for classifying phenomena on the basis of diachronic features, thereby making a provisional case for considering at least some etiological kinds to be natural kinds.

Isaac Levi uses C. S. Peirce's fallibilism as a foil for his own “epistemological infallibilism“. I argue that Levi's criticisms of Peirce do not hit their target, and that the two pragmatists agree on the fundamental issues concerning background knowledge, certainty, revision of belief, and the aims of inquiry.