There are two senses in which a hypothesis may be said to unify evidence: (1) ability to increase the mutual information of a set of evidence statements; (2) explanation of commonalities in phenomena by positing a common origin. On Bayesian updating, only Mutual Information Unification contributes to incremental support. Defenders of explanation as a confirmatory virtue that makes independent contribution must appeal to some relevant difference between humans and Bayesian agents. I argue that common origin unification has at best a limited heuristic role in confirmation. Finally, Reichenbachian common cause hypotheses are shown to be instances of Mutual Information Unification.

In this discussion note, we explain how to relax some of the standard assumptions made in Garber-style solutions to the Problem of Old Evidence. The result is a more general and explanatory Bayesian approach.

Clade selection is unpopular with philosophers who otherwise accept multilevel selection theory. Clades cannot reproduce, and reproduction is widely thought necessary for evolution by natural selection, especially of complex adaptations. Using microbial evolutionary processes as heuristics, I argue contrariwise that (1) clade growth (proliferation of contained species) substitutes for clade reproduction in the evolution of complex adaptation, (2) clade-level properties favoring persistence—species richness, dispersal, divergence, and possibly intraclade cooperation—are not collapsible into species-level traits, (3) such properties can be maintained by selection on clades, and (4) clade selection extends the explanatory power of the theory of evolution.

We attempt to defend the species-as-individuals hypothesis by examining the logical role played by the binomials (e.g., “Homo sapiens,” “Pinus ponderosa”) in biological discourse about species. Those who contend that the binomials can be properly understood as functioning in biological theory as singular terms opt for an objectual account of species and view species as individuals. Those who contend that the binomials can in principle be eliminated from biological theory in favor of predicate expressions opt for a predicative account of species and view species as kinds. We contend that biologists' talk about species is talk about species as individuals, and we conclude that the most plausible account of species is an objectual account.

The purpose of this paper is to test the contemporary concept of biological species against some of the problems caused by treating species as spatiotemporally extended entities governed by criteria of persistence, identity, etc. After outlining the general problem of symmetric division in natural objects, I set out some useful distinctions (section 1) and confirm that species are not natural kinds (section 2). Section 3 takes up the separate issue of species definition, focusing on the Biological Species Concept (BSC). Sections 4 and 5 examine the matter of species identity over space and time respectively, as determined by the BSC. Both gradualistic and punctuated equilibrium models of speciation are discussed. In section 6 I argue that the BSC fails to determine adequate criteria for dealing with certain kinds of speciation. Section 7 moves speculatively beyond the BSC to a brief examination of alternatives.

This paper examines the current variant of the view that meaningful human actions are not amenable to causal, scientific explanation. Rather, the view examined holds that, understanding the language, we understand the meaning of other people's overt acts by analyzing the concepts appropriately applied to the situation, tracing their logical connections with other mentalistic concepts. A matter of conceptual analysis, our understanding of man is held to be a priori and necessary rather than, as with the natural sciences, a posteriori and contingent.

Various uses of ‘concept’, ‘meaning’, and ‘understanding’ are here distinguished. It is then shown, first, how the objectivist can in principle account for intentionality and for “rule-governed” behavior, that is, for the presence and efficacy of mind in the world. Secondly, current criticisms of the objectivist program are examined. An uncritical use of ‘concept’ and of ‘rule’, as well as a fusion of various uses of ‘meaning’ and ‘understanding’, gives those criticisms a specious plausibility that does not withstand close analysis. It is concluded that the objectivist program has not been shown to be untenable.

This paper challenges the exclusion of patients from epistemic practices in psychiatry by examining the creation and revision processes of the Diagnostic and Statistical Manual of Mental Disorders (DSM), a document produced by the American Psychiatric Association that identifies the properties of mental disorders and thereby guides research, diagnosis, treatment, and various administrative tasks. It argues there are epistemic—rather than exclusively social/political—reasons for including patients in the DSM revision process. Individuals with mental disorders are indispensable resources to enhance psychiatric epistemology, especially in the context of the crisis, controversy, and uncertainty surrounding mental health research and treatment.

The Intergovernmental Panel on Climate Change has developed a novel framework for assessing and communicating uncertainty in the findings published in its periodic assessment reports. But how should these uncertainty assessments inform decisions? We take a formal decision-making perspective to investigate how scientific input formulated in the IPCC’s novel framework might inform decisions in a principled way through a normative decision model.

I defend the interpretation of the Aharonov-Bohm effect originally advanced by Aharonov and Bohm, i.e., that it is caused by an interaction between the electron and the vector potential. The defense depends on taking the fiber bundle formulation of electrodynamics literally, or almost literally.

I analyze a number of the quantum no-signalling proofs (Ghirardi et al. 1980, Bussey 1982, Jordan 1983, Shimony 1985, Redhead 1987, Eberhard and Ross 1989, Sherer and Busch 1993). These purport to show that the EPR correlations cannot be exploited for transmitting signals, i.e., are not causal. First, I show that these proofs can be mathematically unified; they are disguised versions of a single theorem. Second, I argue that these proofs are circular. The essential theorem relies upon the tensor product representation for combined systems, which has no physical basis in the von Neumann axioms. Historically, the construction of this representation scheme by von Neumann and Weyl built no-signalling assumptions into the quantum theory. Signalling between the wings of the EPR-Bell experiments is unlikely but is not ruled out empirically by the class of proofs considered.

Because statements like ‘This object is soluble in aqua regia’ involve the causal modalities, we call them causal dispositional statements. Now while this involvement has long been recognized, no thorough examination of its exact nature has ever been made. One purpose of this paper is to begin such an examination. In Sec. 2 we will suggest an analysis of causal dispositional statements, and in Sec. 3 we will discuss some philosophic issues to which this analysis is relevant.

Four philosophical problems—predication, speech acts, rules, and innate ideas— are discussed in the light of their implications for psychological and linguistic research. The discussion of predication concerns both form and use. With respect to form, it is argued that our lexical memory is organized according to a predicate-argument formula that underlies the subject-predicate form of our sentences. With respect to use, it is argued that the illocutionary force of the sentence as a speech act must be taken into account. Both the formation and the use of such verbal constructions are normally characterized by systems of rules, but there is no clear account of what a rule is or how it might operate to control behavior, and this problem is especially difficult when, as in language, the person's knowledge of the rules is implicit. The innate basis for our human ability to acquire linguistic rules is considered and the problem of innateness is redefined around the conjecture that there are innate, language-specific mechanisms unique to human beings. The problem of investigating such language-specific mechanisms psychologically, however, is quite difficult at the present time.

By observing a black swan, one ascertains an interesting zoological fact. The fact involves two items, a specific object and the property of being a black swan, and consists in the former instantiating the latter. The object is in itself of little interest. Our environment abounds in objects, and knowledge is hardly enhanced by one of them being merely picked out for consideration. The same goes for the property. Properties are at least as plentiful as objects and one does not get to know anything by merely focussing attention upon one of them. What is of interest is the combination of the two items, i.e. the circumstance that the object instantiates the property. And this is what the said fact consists in.

In this paper I provide a novel argument against the claim that classical genetics is being reduced to molecular genetics. Specifically, I demonstrate that reductionists must subscribe to the unargued and problematic thesis that molecular genetics is ‘independent’ of classical genetics. I also argue that several standard antireductionist positions can be faulted for unnecessarily conceding the Independence Thesis to the reductionists. In place of a ‘tale of two sciences’, I offer a ‘heroic’ stance that denies classical genetics is being reduced, yet sees classical and molecular genetics as fundamentally unified.

Skipper and Millstein analyze natural selection and mechanism, concluding that natural selection is not a mechanism in the sense of the new mechanistic philosophy. Barros disagrees and provides his own account of natural selection as a mechanism. This discussion identifies a missing piece of Barros's account, attempts to fill in that piece, and reconsiders the revised account. Two principal objections are developed: one, the account does not characterize natural selection; two, the account is not mechanistic. Extensive and persistent variability causes both of these difficulties, so further attempts to describe natural selection as a mechanism are also unlikely to succeed.

Sober and Lewontin's critique of genic selectionism is based upon the principle that a unit of selection should make a context-independent contribution to fitness. Critics have effectively shown that this principle is flawed. In this paper I show that the context independence principle is an instance of a more general principle for characterizing causes,called the contextual unanimity principle. I argue that this latter principle, while widely accepted, is erroneous. What is needed is to replace the approach to causality characterized by the contextual unanimity criterion with an approach based on the concept of causal mechanism. After sketching such an approach, I show how it can be used to shed light on the units of selection problem.

My thesis is that biology is most plausibly regarded as a universal, as distinct from a provincial, science. First, I develop the general notion of a provincial science, formulate three criteria for applying the concept, and present brief examples illustrating their use. Second, I argue that a consideration of population genetics as a characteristic example of a basic biological theory strengthens the prior presumption that biology is not a provincial science. Finally, I examine two arguments to the effect that biology is a provincial science. The first concerns biology's exclusively terrestrial evidence base, the second the logical character of its laws. I introduce considerations that weaken the persuasiveness of the first argument and then show that the second one rests upon a false premise and so should be rejected.

The distinction between psychology, logic, and epistemology is a commonplace. The first treats of experience as an act, experience in its relation to the individual observer. The second concerns itself with the internal marks by which truth may be distinguished from error, and in so far as it deals with experience, has to do with some sort of validity of the experience as evidence of a truth. The third discusses in a general way all the elements—observer, object, immediate presentation—which enter into the experience.

Phylogenetic information is often necessary to distinguish between evolutionary scenarios. Recently, some prominent proponents of evolutionary psychology have acknowledged this, and have claimed that such evidence has in fact been brought to bear on adaptive hypotheses involving complex human psychological traits. Were this possible, it would be a valuable source of evidence regarding hypothesized adaptive traits in humans. However, the structure of the Hominidae family makes this difficult or impossible. For many traits of interest, the closest extant relatives to the human species are too phenotypically different from humans for such methods to provide meaningful data. While phylogenetic information can be useful for testing adaptive hypotheses in humans, these generally involve traits that are (a) not widely shared in the species or (b) fairly widely shared in the Hominidae family, and hence likely of a lower order of complexity than the sorts of traits evolutionary psychology has so far been interested in.

The traditional view of evolutionary theory asserts that we can usefully understand natural selection, drift, mutation, migration, and the system of mating as forces that cause evolutionary change. Recently, Denis Walsh and Robert Brandon have objected to this view. Walsh argues that the traditional view faces a fatal dilemma and that the force analogy must be rejected altogether. Brandon accepts the force analogy but argues that drift, rather than the Hardy-Weinberg law, is the best candidate for a zero-force law. Here I defend the traditional view against these objections.