I discuss two ways of justifying reflection principles. First, I propose that an undogmatic reading of dynamic Dutch book arguments provides them with a sound foundation. Second, I show also that minimizing expected inaccuracy leads to a novel argument for reflection principles. The required inaccuracy measures comprise a natural class of functions that can be derived from a generalization of a condition known as propriety or immodesty. This shows that reflection principles are an essential feature not just of consistent degrees of belief but also of degrees of belief that approximate truth.

Where E is the proposition that [If H and O were true, H would explain O], William Roche and Elliot Sober have argued that P(H | O&E) = P(H | O). In this article I argue that not only is this equality not generally true, it is false in the very kinds of cases that Roche and Sober focus on, involving frequency data. In fact, in such cases O raises the probability of H only given that there is an explanatory connection between them.

One of the most troubling and persistent challenges for Bayesian Confirmation Theory is the Problem of Old Evidence (POE). The problem arises for anyone who models scientific reasoning by means of Bayesian Conditionalization. This article addresses the problem as follows: First, I clarify the nature and varieties of the POE and analyze various solution proposals in the literature. Second, I present a novel solution that combines previous attempts while making weaker and more plausible assumptions. Third and last, I summarize my findings and put them into the context of the general debate about POE and Bayesian reasoning.

Here I explore a novel no-collapse interpretation of quantum mechanics that combines aspects of two familiar and well-developed alternatives, Bohmian mechanics and the many-worlds interpretation. Despite reproducing the empirical predictions of quantum mechanics, the theory looks surprisingly classical. All there is at the fundamental level are particles interacting via Newtonian forces. There is no wave function. However, there are many worlds.

The Ultimatum Game is one of the most successful experimental designs in the history of the social sciences. In this article I try to explain this success—what makes it a “paradigmatic experiment”—stressing in particular its versatility. Despite the intentions of its inventors, the Ultimatum Game was never a good design to test economic theory, and it is now mostly used as a heuristic tool for the observation of nonstandard preferences or as a “social thermometer” for the observation of culture-specific norms.

We use a theorem from M. J. Schervish to explore the relationship between accuracy and practical success. If an agent is pragmatically rational, she will quantify the expected loss of her credence with a strictly proper scoring rule. Which scoring rule is right for her will depend on the sorts of decisions she expects to face. We relate this pragmatic conception of inaccuracy to the purely epistemic one popular among epistemic utility theorists.

There is sufficient evidence at present to justify the belief that the universe began to exist without being caused to do so. This evidence includes the Hawking-Penrose singularity theorems that are based on Einstein's General Theory of Relativity, and the recently introduced Quantum Cosmological Models of the early universe. The singularity theorems lead to an explication of the beginning of the universe that involves the notion of a Big Bang singularity, and the Quantum Cosmological Models represent the beginning largely in terms of the notion of a vacuum fluctuation. Theories that represent the universe as infinitely old or as caused to begin are shown to be at odds with or at least unsupported by these and other current cosmological notions.

Providing a precise statement of their position has long been a central challenge facing scientific realists. This article draws some morals about how realism ought to be formulated from the renormalization group framework in high-energy physics.

This article calls into question the charge that frequentist testing is susceptible to the base-rate fallacy. It is argued that the apparent similarity between examples like the Harvard Medical School test and frequentist testing is highly misleading. A closer scrutiny reveals that such examples have none of the basic features of a proper frequentist test, such as legitimate data, hypotheses, test statistics, and sampling distributions. Indeed, the relevant error probabilities are replaced with the false positive/negative rates that constitute deductive calculations based on known probabilities among events. As a result, the ampliative dimension of frequentist induction—learning from data about the underlying data-generating mechanism—is missing.

Among mycologists, questions persist about what entities should be treated as the fundamental units of fungal populations. This article articulates a coherent view about populations of heterokaryotic fungi and the individuals that comprise them. Using Godfrey-Smith’s minimal concept of a Darwinian population, I argue that entities at two levels of the biological hierarchy satisfy the minimal concept in heterokaryotic fungi: mycelia and nuclei. I provide a preliminary answer to the question of how to understand the relation between these two populations. This article contributes to discussions about the nature of biological individuality, organismality, and evolutionary transitions.

I argue against the currently popular view that a radical change in theory affects the meaning of theoretical terms, and hence render pre- and post-shift theories incomparable. I first show how to pose the meaning-change issue without appeal to meanings reified. I contend that arguments against theory-neutral observation languages are faulty, but that even if they were sound, there are semantic devices that allow a theory to refer to the factual basis of a competitor. This suggests a picture of science as the accumulation of truths, with each successive stage being more stable.

Robustness concepts are often invoked to manage two obstacles confronting models of ecological systems: complexity and uncertainty. The intuitive idea is that any result derived from many idealized but credible models is thereby made more reliable or is better confirmed. An appropriate basis for this inference has proven elusive. Here, several representations of robustness analysis are vetted, paying particular attention to complex models of ecosystems and the global climate. The claim that robustness is itself confirmatory because robustness analysis employs a Bayesian variety-of-evidence argument is criticized, but recent overwhelming pessimism about robustness may have a silver lining.

A number of formal models, including a highly influential model from Hong and Page, purport to show that functionally diverse groups often beat groups of individually high-performing agents in solving problems. Thompson argues that in Hong and Page’s model, that the diverse groups are created by a random process explains their success, not the diversity. Here, I defend the diversity interpretation of the Hong and Page result. The failure of Thompson’s argument shows that to understand the value of functional diversity, we should be clearer about how we conceive of and measure that diversity.

The first use of the term “information” to describe the content of nervous impulse occurs in Edgar Adrian's The Basis of Sensation (1928). What concept of information does Adrian appeal to, and how can it be situated in relation to contemporary philosophical accounts of the notion of information in biology? The answer requires an explication of Adrian's use and an evaluation of its situation in relation to contemporary accounts of semantic information. I suggest that Adrian's concept of information can be to derive a concept of arbitrariness or semioticity in representation. This in turn provides one way of resolving some of the challenges that confront recent attempts in the philosophy of biology to restrict the notion of information to those causal connections that can in some sense be referred to as arbitrary or semiotic.

Language is the primary fact which concerns contemporary philosophy. Men have been speaking and writing for a long time, but it is only recently that the task of philosophy has been said to be the analysis of language. Ethical perplexities, social anxieties, the nature of scientific knowledge, religious speculations, are held not to be directly the problems of the philosopher. They enter his study by way of a domain of languages and sub-languages. This preoccupation with language is itself an unusual phenomenon in our intellectual history. It challenges the sociologist of philosophic ideas for an explanation, and it leads one to wonder upon what evidence philosophers have accepted the doctrine of linguistic primacy.

By a logical theory I mean a formal system together with its semantics, meta-theory, and rules for translating ordinary language into its notation. Logical theories can be used descriptively (for example, to represent particular arguments or to depict the logical form of certain sentences). Here the logician uses the usual methods of empirical science to assess the correctness of his descriptions. However, the most important applications of logical theories are normative, and here, I argue, the epistemology is that of wide reflective equilibrium. The result is that logic not only assesses our inferential practice but also changes it. I tie my discussion to Thagard's views concerning the relationship between psychology and logic, arguing against him that psychology has and should have only a peripheral role in normative (and most descriptive) applications of logic.

This paper aims to establish three major theses: (1) Not only declarative sentences, but also interrogatives and imperatives, may be classified as true or as false. (2) Declarative, imperative, and interrogative utterances may also be classified as honest or as dishonest. (3) Whether an utterance is honest or dishonest is logically independent of whether it is true or is false.

The establishment of the above theses follows upon the adoption of a principle for identifying what is meant by any sentence, declarative, interrogative, or imperative. The analysis aims to show that meaning is to be attributed to the uttered or written sentence-token, rather to the thereby exhibited sentence-type. Further, the meaning of the sentential token is to be identified with a purpose of the speaker, that the speaker would reveal to the addressee by uttering the sentence.

The to be revealed purpose is analysed into two components: an ultimate concern (that the addressee stand in such and such a relation—e.g., of believing, or informing the speaker about, or making it true that) and an ultimate topic of concern (the state of affairs, i.e., proposition, relative to which the speaker would have the addressee stand in the specified relation).

Sentential utterances “signify” different purposes by “expressing” different ultimate concerns and “indicating ”different ultimate topics of concern. Variations in expressed concern are correlated with variations in sentential form, such as declarative, interrogative and imperative. Variations in indicated topic of concern are correlated with variations in the subject and predicate of the uttered sentence. Thus, for example, utterances of “Johnny will jump in the lake,” “Will Johnny jump in the lake?” and “Johnny, go jump in the lake! ” all indicate one and the same ultimate topic of concern but express different ultimate concerns with this topic.

A sentential utterance is true or false according as its indicated topic of concern is true or false. Hence, declaratives, interrogatives and imperatives may all be classified as true or as false. But honesty or dishonesty is a function (explained in the paper) of the expressed concern, rather than of the topic of concern. Hence, although utterances of all sentential forms are honest or dishonest, their honesty or dishonesty is logically independent of their truth or falsity.

In his 1983 article, Paul A. Roth defends the Quinean project of naturalized epistemology from the criticism presented in my 1980 article. In this note I would like to respond to Roth's effort. I will argue that, while helpful in advancing and clarifying the issues, Roth's defense of naturalized epistemology does not succeed. The primary topic to be clarified is Quine's “no first philosophy” doctrine; but I will address myself to other points as well.

The purpose of this paper is to show that there are as many formulations of the process of falsification as there are archetypal, philosophical systems of inquiry. This paper explores several systems of inquiry which are based on Churchman's reading of the history of Western epistemology. It is argued that (1) the falsification of scientific theories can never be a purely formal process although it is perpetually open to formal exploration ; (2) that contrary to current belief, falsification can never be more certain than confirmation because falsification involves judgments which are no more certain than those involved in confirmation. The supposed asymmetry between confirmation and falsification is severely challenged. Finally, a Feyerabendian and a Hegelian notion of falsification are explicitly developed and contrasted.