The existence of fields besides gravitation may provide us with a way to decide empirically whether spacetime is really a nonflat Riemannian manifold or a flat Minkowskian manifold that appears curved as a result of gravitational distortions. This idea is explained using a modification of Poincaré's famous ‘diskworld’.

“All experience is an arch wherethro’ gleams” an untravell'd world and through which come the joyous adventures of life and also grief and pain. Since all that we know and hope to know and think we know must come through this arch and since the primary task of science is the validation and enlargement of knowledge, science is vitally interested in this experience and its interpretation. This interest stems not from the philosopher's epistemology but it is strictly operational. We want to know what kind of experience yields reliable knowledge when checked against other experience and applied in practical adjustment to things as they are and to prediction of the probable future course of events. In short, the field of natural science (empirical as distinguished from normative science like mathematics) embraces everything that comes within the range of human experience. Its specific functions are to codify this mixed experience, to search out those uniformities which yield classification, verification and prediction, and from these observed uniformities to construct by sound reasoning verifiable laws, hypotheses and theories, that is, to find the meaning of the experiences had. First we want to know the facts, but what we are after in the upshot is the interpretation of the facts.

Skyrms's formulation of the argument against stochastic hidden variables in quantum mechanics using conditionals with chance consequences suffers from an ambiguity in its “conservation“ assumption. The strong version, which Skyrms needs, packs in a “no-rapport” assumption in addition to the weaker statement of the “experimental facts.“ On the positive side, I argue that Skyrms's proof has two unnoted virtues (not shared by previous proofs): (1) it shows that certain difficulties that arise for deterministic hidden variable theories that exploit a non-classical probability theory extend to the stochastic case; (2) the use of counterfactual conditionals relates the Bell puzzle to Dummett's (1976) discussion of realism in quantum mechanics.

The demonstration that slow transport of clocks can be used to define simultaneity in inertial frames of reference leads to the question of whether clock transport can similarly be used in noninertial frames. It is shown that there are certain types of reference frames in which the clock-transport method cannot be used in a self-consistent manner. It is also shown that there are other types of noninertial frames in which the clock-transport method will succeed. The discussion includes noninertial frames in flat space-time as well as the case of curved space-times.

The evolution of the myxoma virus in Australia has been presented for many years as a test case for the hypothesis that group selection can function effectively ‘in the wild.’ This paper critically examines the myxoma case, and argues that its failure as a test case for this hypothesis has broader implications for debates over the levels of selection.

A (normalized) interpolant I in Craig's theorem is a kind of explanation why the consequence relation (from F to G) holds. This is because I is a summary of the interaction of the configurations specified by F and G, respectively, that shows how G follows from F. If explaining E means deriving it from a background theory T plus situational information A and if among the concepts of E we can separate those occurring only in T or only in A, then the interpolation theorem applies in two different ways yielding two different explanations and two different covering laws.

I use an explanation of Yanomami warfare given by the anthropologist Brian Ferguson as a case study to compare the merits of the causal and unification approaches to explanation. I argue that Ferguson's insistence on explaining actual occurrences and patterns of Yanomami warfare together with his claim that all of his generalizations are statistical raises difficulties for the unification approach, because of its commitment to “deductive chauvinism.” Moreover, I show that there are serious difficulties involved in comparing the “unifying power” of Ferguson's explanations to those of his competitors. I show that the causal approach can provide a rich analysis of Ferguson's explanation while avoiding these difficulties.

The Sleeping Beauty problem has spawned a debate between “thirders” and “halfers” who draw conflicting conclusions about Sleeping Beauty's credence that a coin lands heads. Our analysis is based on a probability model for what Sleeping Beauty knows at each time during the experiment. We show that conflicting conclusions result from different modeling assumptions that each group makes. Our analysis uses a standard “Bayesian” account of rational belief with conditioning. No special handling is used for self-locating beliefs or centered propositions. We also explore what fair prices Sleeping Beauty computes for gambles that she might be offered during the experiment.

Scholars belong to multiple communities of credit simultaneously. When these communities disagree about a scholarly achievement’s credit assignment, this raises a puzzle for decision and game theoretic models of credit seeking in science. The reference class problem for credit valuation in science is the problem of determining to which of an agent’s communities—which reference class—credit determinations should be indexed for an act under some state of nature. Solving this problem requires developing rich, mutually informed theories of community and credit that are sensitive to the structure and status systems of complex, heterogeneous scholarly networks.

A working theory can involve a compromise between pragmatic application and pure theory. This is illustrated by the development of Coombs's theory of data. The original version of the theory purported to guide investigators in the use of scaling techniques, but subsequent revisions including a logico-mathematical statement of the theory do not show whether the practical recommendations made earlier still apply. These practical recommendations, some of which Coombs has discarded to obtain a comprehensive theory, are important in spite of shortcomings as they reveal differences between attitude and mental test data. The different forms of Coombs's theory point to the existence of a general problem, how to find a compromise between practice and pure theory.

This essay develops a theory of natural signs in order to show how evolutionary theory breathes new life into teleology. An argument to the contrary presented by Richard Taylor is refuted. The essay defends the view that the concept of negative feedback explicates purposiveness and that symbiotic evolution explains the occurrence of naturally adapted feedback systems. But evolution itself is not a teleological process, nor is it a negative feedback system. There is an exploration of the nature of the dissatisfaction we feel with an evolutionary account of purposiveness from which the fortuitous cannot be eliminated.

Despite a vast philosophical literature on the epistemology of mathematics and much speculation about how, in principle, knowledge of this domain is possible, little attention has been paid to the psychological findings and theories concerning the acquisition, comprehension and use of mathematical knowledge. This contrasts sharply with recent philosophical work on language where comparable issues and problems arise. One topic that is the center of debate in the study of mathematical cognition is the question of innateness. This paper critically examines the controversy.

According to Woodward’s causal model of explanation, explanatory information is relevant for manipulation purposes and indicates by means of invariant causal relations how to change the value of certain target explanandum variables by intervening on others. Therefore, the depth of an explanation is evaluated through the size of the domain of invariance of the generalization involved. In this article, I argue that Woodward’s account of explanatory relevance is still unsatisfactory and claim that the depth of an explanation should be explicated in terms of the size of the domain of circumstances which it designates as leaving the explanandum unchanged.

Social scientific development has been greatly influenced by Galilean-Newtonian thought which emphasized formulation of abstract hypotheses valid throughout all time and space and independent of human characteristics. This influence has resulted in an artificial hiatus between social science and social problem-solving. Dissolution of certain Galilean-Newtonian assumptions has opened the way for integrating aspects of another stream of thought, the Hegelian-Marxian one, into the social scientific endeavor. Hegelian-Marxian thought emphasizes the individual becoming self-conscious of, and involved in, the social-historical process. The uniting of certain aspects of Galilean-Newtonian and Hegelian-Marxian thought provides a genuinely experimental social science in which abstract hypothesis-testing is united with social action that is based on persons’ awareness of relevant hypotheses viewed in historical perspective.

Introduction. Topology (sometimes called analysis situs) is the most general and most fundamental branch of geometry. Logically its study should precede that of other kinds of geometry. But mathematical knowledge, whether regarded as part of our cultural heritage or as the possession of an individual, does not come into being like a building, from a completed foundation to a limited superstructure, but rather grows like a tree with ever-deepening roots as well as ever-spreading branches. So, historically, systematic studies in topology lagged behind Euclid's elements some 2000 years and were unknown a century ago. There has, however, been considerable activity in this field by the present generation, and a number of modern treatments are available for the specialist. In spite of its fundamental nature, the subject is difficult, and many of its problems remain unsolved even today. This difficulty makes it pedagogically advisable to avoid questions of topology germane to other branches of mathematics and there is a distinct scarcity of material available even to the mathematician, whose main interest lies outside this field.

Some scientists believe that although evolutionary theory is explanatory, it does not have, in contrast to the theories of physics, any predictive power. This raises the question of its testability. The analysis given shows that there are good reasons to claim the unpredictability of evolutionary events; nevertheless, the evolutionary theory has potential predictive power. It is argued that the difference between biology and physics lies not in the predictive power of the theories involved, but in the different weight which is lent to the forecasting of particular events in these sciences. A second source of confusion derives from the ambiguity of the term ‘prediction’. In order to define ‘prediction’ for cases in which the term is used to refer to a part of testing procedure, the reference to the time-point “now” is quite irrelevant. Prediction of unknown observational data is sufficient for testing a hypothesis, but such prediction may or may not be identical with forecasting of future events. Different factors that may cause particular difficulties met by biologists in forecasting future events are analyzed subsequently in the second part of the paper. The conclusion is drawn that although particular cognitive situations limiting the ability of forecasting are very frequent in biological sciences, the claim about the peculiar logical status of biological theories is not thereby justified.

Treating species as individuals and not classes has been crucial to the integration of evolutionary theory with modern systematics. Despite the theoretically important role the concept of individuality plays in modern phylogenetic systematics and in evolutionary theory more generally, many have been content to rely on common-sense intuitions about what counts as an individual. One of the most often cited intuitions is that individuals should be defined intrinsically. Unfortunately, common-sense intuitions like this one have proven to be inadequate for identifying and characterizing historical individuals (like species). An examination of real-world biological examples shows that our common-sense intuitions are equally inadequate when applied to at least some biological organisms—the paradigm individuals.

An empirical law or evidence which supports a theory tends to have the greatest scientific value when it seemed improbable before it was investigated. Evidence which falsifies a theory tends to have the greatest value when it seemed probable that the investigation would confirm the theory. A scientist who wishes to optimize his contribution to knowledge probably will investigate most frequently hypotheses which seem neither very probable nor very improbable of being confirmed. This strategy leads neither to a maximum number of confirmations of a theory, nor to a set of tests which are maximally severe.