Empirical adequacy, formal explanation and understanding are distinct goals of science. While no a priori criterion for understanding should be laid down, there may be inherent limitations on the way we are able to understand explanations of physical phenomena. I examine several recent contributions to the exercise of fashioning an explanatory discourse to mold the formal explanation provided by quantum mechanics to our modes of understanding. The question is whether we are capable of truly understanding (or comprehending) quantum phenomena, as opposed to simply accepting the formalism and certain irreducible quantum correlations. The central issue is that of understanding versus merely redefining terms to paper over our ignorance.

Usual derivations of Lüders's projection rule show that Lüders's rule is the rule required by quantum statistics to calculate the final state after an ideal (minimally disturbing) measurement. These derivations are at best inconclusive, however, when it comes to interpreting Lüders's rule as a description of individual state transformations. In this paper, I show a natural way of deriving Lüders's rule from well-motivated and explicit physical assumptions referring to individual systems. This requires, however, the introduction of a concept of individual state which is not standard.

Recent studies have shown that Einstein did not write the EPR paper and that he was disappointed with the outcome. He thought, rightly, that his own argument for the incompleteness of quantum theory was badly presented in the paper. We reconstruct the argument of EPR, indicate the reasons Einstein was dissatisfied with it, and discuss Einstein's own argument. We show that many commentators have been misled by the obscurity of EPR into proposing interpretations of its argument that do not accurately represent Einstein's own views. Finally, we evaluate Einstein's own incompleteness argument, concluding that recent experimental findings have likely shown it to be unsound.

A model of a Markov process is presented in which observing the present state of a system is asymmetrically related to inferring the system's future and inferring its past. A likelihood inference about the system's past state, based on observing its present state, is justified no matter what the parameter values in the model happen to be. In contrast, a probability inference of the system's future state, based on observing its present state, requires further information about the parameter values.

The New Theory of Reference (NTR) of Marcus, Kripke, Kaplan, Putnam and others is a theory in the philosophy of language and there has been much debate about whether it entails the metaphysical theory of essentialism. But there has been no discussion about whether the NTR entails another metaphysical theory, the absolutist theory of time and space. It is argued in this paper that the NTR carries this entailment; the theory of time is the main focus of the paper and it is argued that the NTR entails the absolutist theory that times are event-independent moments.

A correct analysis of hierarchical selection processes must specify 1) the objects that succeed differentially as units, and 2) the properties that provide the causal bases for differential success. Here I illustrate how failing to recognize the units/bases distinction creates a contradiction in Elliott Sober's recent account of selection. A revised criterion for units of selection is developed and applied to examples at several biological levels. Criteria for bases of selection are discussed in terms of the degree of context-dependence and directness of a property's effect on the success of units. The significance of previous work by Sober, Wimsatt and Brandon is thereby clarified.

In this paper, I develop a naturalistic conception of evolutionary progress. I argue that the Waddingtonian notion of adaptability can be embedded meaningfully into a framework which views living things as nonequilibrium structures. This thermodynamic interpretation places great emphasis on the dynamics of environmental change, whereas the classical conceptions are based on equilibrium conceptions of the evolutionary process. What improves in evolution is the ability of living things to stay alive in increasingly heterogeneous environments.

This paper attempts to clarify the meaning and significance of “qualitative confirmation”. The need to do so is related to the fact that, without such a conceptualization, a large portion of the human sciences are relegated to a less than scientific status. Accordingly, “qualitative confirmation” is viewed as a proper subset of traditional confirmation theory. To establish such a case, a general Hempelian framework is utilized, but it is supplemented with two additional levels of confirmation. It is concluded that the final test for adequacy of such confirmation must rest on a subjective probability notion.

The logical empiricists knew that scientific theories sometimes arise out of the attempt to reconcile or unify two existing theories. They also thought that, at best, old theories would be retained as approximations to their successors. Kuhn lost both insights when he rejected the logical empiricists' formal approach in favor of an exclusively historical and psychological one. But when Putnam tried to restore such ideas he failed to provide them with the historical support they require. An account of revolutionary unifications is defended as reconciling Putnam's realist ideas about methodology with Kuhn's historical approach.

Rationality demands at least that we eliminate incoherencies among our beliefs when we are apprised of them. This minimal requirement gives us no grounds for condemning a refusal to look for incoherencies, or indeed to deliberate altogether. Several stronger conditions on rationality are explored and rejected. There are presently no good arguments against logical sloth.

In a recent article, Goldstick and O'Neill propose a definition for the comparative “truer than” relation between rival propositions. This definition is studied here in a context where the concept of “convexity” is well defined for propositions. It turns out that the Goldstick-O'Neill definition gives a reasonable but very restricted sufficient condition for the “truer than” relation, but fails as a necessary condition.

Paul Churchland has recently argued that empirical evidence strongly suggests that perception is penetrable to the beliefs or theories held by individual perceivers (1988). While there has been much discussion of the sorts of psychological cases he presents, little has been said about his arguments from neurology. I offer a critical examination of his claim that certain efferents in the brain are evidence against perceptual encapsulation. I argue that his neurological evidence is inadequate to his philosophical goals, both by itself and taken in concert with his psychological evidence.