There does not seem to be a consistent way to ground the concept of “force” in Cartesian first principles. In this article, I first review the literature on the subject. Then, I offer an alternative interpretation of force—one that seems to be coherent and consistent with Descartes’ project. Not only does the new position avoid the problems of previous interpretations, but it does so in such a way as to support and justify those previous interpretations.

1. Introduction. The purpose of this paper is to present an initial sociological analysis of science as an institution. This kind of analysis has long been made of other aspects of culture: of the family, the state, religion, economic enterprise and the like. An institution, as the term is used here, is simply

Theoretical simplicity is difficult to characterize, and evidently can depend upon a number of distinct factors. One such desirable characteristic is that the laws of a theory have relatively few “counterinstances” whose accommodation requires the invocation of a ceteris paribus condition and ancillary explanation. It is argued that, when one theory is reduced to another, such that the laws of the second govern the behavior of the parts of the entities in the domain of the first, there is a characteristic gain in simplicity of the sort mentioned: while I see no way of quantitatively measuring the “amount” of defeasibility of the laws of a theory, microreduction can be shown to decrease that “amount.”

Bertrand Russell, in one of his gentler jibes at the pragmatists, says that this school would obviously prefer Othello, the man of action to Hamlet, the man of thought. This figure is singularly inept since Hamlet brought about the death of six people through violent action. That more than equalled the score rolled up by the presumably more active Othello. What Hamlet lacked was not the power to act but an adequate theory of action. Having first attempted to avoid the issue presented by the murder of his father, he is swept up in a gale of violence because of that very attempt at avoidance.

Concerning any object of philosophical analysis, we can ask several questions, including the two posed in the title of this paper. Despite difficulties in formulating a precise criterion to distinguish causal processes from pseudoprocesses, and causal interactions from mere spatiotemporal intersections, I argue that Salmon answered the first of these questions with extraordinary clarity. The second question, by contrast, has received very little attention. I will present two problems: in the first, it seems that Salmon has provided exactly the conceptual resources needed to solve the problem; in the second, it is difficult to see how causal processes and interactions may be used to shed any light. In general, the way to carry Salmon's program forward will be to demonstrate that these resources can be made to do real philosophical work.

The general context of this paper is the locality problem in quantum theory. In a recent issue of this journal, Rédei (1991) offered a proof of the proposition that algebraic Lorentz-covariant quantum field theory is past stochastic Einstein local. We show that Rédei's proof is either spurious or circular, and that it contains two deductive fallacies. Furthermore, we prove that the mentioned theory meets the stronger condition of stochastic Haag locality.

This paper addresses the problem that Bayesian statistical inference cannot accommodate theory change, and proposes a framework for dealing with such changes. It first presents a scheme for generating predictions from observations by means of hypotheses. An example shows how the hypotheses represent the theoretical structure underlying the scheme. This is followed by an example of a change of hypotheses. The paper then presents a general framework for hypotheses change, and proposes the minimization of the distance between hypotheses as a rationality criterion. Finally the paper discusses the import of this for Bayesian statistical inference.

Millikan (1993) and Wilson (1994) argue, for different reasons, that the essential reference to the environment in adaptationist explanations of behavior makes (psychological) individualism inconsistent with evolutionary psychology. I show that their arguments are based on misinterpretations of the role of reference to the environment in such explanations. By exploring these misinterpretations, I develop an account of explanation in evolutionary psychology that is fully consistent with individualism. This does not, however, constitute a full-fledged defense of individualism, since evolutionary psychology is only one explanatory paradigm among many in psychology.

Econophysics is a branch of economics that applies concepts and methods from physics to the financial markets. This article focuses on the approaches to quantum finance developed by Kirill Ilinski and Belal E. Baaquie to deal with the uncertainty characterizing financial time series. Allegedly, their models rest on a formal analogy between quantum mechanics and finance. In order to evaluate them, we raise the question what is really quantum in quantum econophysics. We then argue that the supposed analogy breaks in an important manner, which is relevant to explain the empirical success of the proposed models.

Critics of functional explanations in social science maintain that such explanations are illegitimate unless a mechanism is specified. Others argue that mechanisms are not necessary for causal inference and that functional explanations are a type of causal claim that raise no special difficulties for testing. I show that there is indeed a special problem that confronts testing functional explanations resulting from their connection to second-order causal claims. I explain how mechanisms can resolve this difficulty, but argue that this does not provide support for methodological individualism since it is not necessary that the mechanisms be described in terms of individual interactions.

In a recent paper, Michael Levin argues that both statements reporting causal relations and causal explanatory statements are extensional. We show that his argument for the extensionality of causal explanatory statements fails to establish that conclusion. His claim that certain ‘because’ statements are elliptical for statements of what he terms the ‘causal explanatory’ form is unsubstantiated. The argument for the referential transparency of the allegedly explanatory form, regardless of whether it is a distinct explanatory form, fails because of scope problems. Finally, we argue that the apparent referential opacity of explanations, the attribution of certain kinds of properties to explanations, and our satisfaction with explanations in what appear to be disparate forms are best accounted for, not by the assumption of ellipticality of statements in various forms for statements in some inherently explanatory form, but rather by an account of explanation as a speech act, the success or failure of which may be affected by which of several co-referring expressions is employed.

A philosophically important but largely overlooked cognitive theory is examined, one that provides information on which inferences an agent will make from his beliefs. Such a theory of feasible inferences is indispensable in a complete cognitive psychology, in particular, for predicting the agent's actions on the basis of rationality conditions and attributed beliefs and desires. However, very little of the feasibility theory which applies to a typical human being can be shown a priori to apply to all agents. The logical competence required of a rational agent seems to have a cluster structure: it cannot be the case that an agent is able to make no inferences, but an agent can be unable to make any particular one.

Accompanying the decline of empiricism in the theory of knowledge has been an increased interest in the social determinants of knowledge and an increased recognition of the fundamental place in the constitution of knowledge occupied by accepted cognitive practices. The principal aim of this paper is to show how a view of knowledge that fully recognizes the role of these practices can adequately treat a topic that is widely considered to be an insuperable obstacle to such a view. The topic is that of scientific realism, of the independence with respect to cognitive practices of certain objects of knowledge.

The likelihood principle of Bayesian statistics implies that information about the stopping rule used to collect evidence does not enter into the statistical analysis. This consequence confers an apparent advantage on Bayesian statistics over frequentist statistics. In the present paper, I argue that information about the stopping rule is nevertheless of value for an assessment of the reliability of the experiment, which is a pre-experimental measure of how well a contemplated procedure is expected to discriminate between hypotheses. I show that, when reliability assessments enter into inquiries, some stopping rules prescribing optional stopping are unacceptable to both Bayesians and frequentists.

It is proposed in this paper to develop a method by which the most general problem of the algebra of propositions is solved. This problem is to construct all propositions whose truth is independent of the form of the variables. As might be expected this method will enable us to determine without the use of matrices the consistency and independence of propositions, except in the case of those fundamental properties, which taken together define consistency itself. In the discussion which follows no limitations are placed on the meaning of the terms and the word proposition is used simply in the sense of a variable. If we were to say, for example, that our variables must be restricted to zero or one values, we would be introducing a limitation which would reduce the generality of our science. A logic may be false in the sense that its postulates lead to contradictory theorems, or it may be false in the sense that it lacks generality, and the situation is not saved by calling it a two-valued, or a three-valued logic, or a logic of “propositions,” or by designating it by some other euphuism.

1. Introduction Dirac's (Dirac 1928) theory of the electron was the first widely accepted relativistic quantum theory, and it later provided the basis for constructing the modern electromagnetic theory of quantum electrodynamics (QED). Whereas Dirac's theory in its simplest form describes relativistic freely-propagating massive non-chiral particles of spin-½, QED describes how such particles interact with one another electromagnetically, via a dynamical quantum field.

Hacking argues against van Fraassen's constructive empiricism by appeal to features of microscopic imaging. Hacking relies on both our practices involving imaging instruments and the structure of the images produced by these micropractices. Van Fraassen's reply is formally correct yet fundamentally unsatisfying. I aim to strengthen van Fraassen's reply, but must then extend constructive empiricism, specifically the central notion of “theoretical immersion.” I argue that immersion is more analogous to entering a virtual reality than to learning a language. This metaphor assimilates instrument-based practice as well as theoretical debate and explanation, and can provide an anti-realist view of our micro-practices consonant with constructive empiricism.

Probability theory is important not least because of its relevance for decision making, which also means: its relevance for the single case. The frequency theory of probability on its own is irrelevant in the single case. However, Howson and Urbach argue that Bayesianism can solve the frequentist's problem: frequentist-probability information is relevant to Bayesians (although to nobody else). The present paper shows that Howson and Urbach's solution cannot work, and indeed that no Bayesian solution can work. There is no way to make frequentist probability relevant.

I am grateful for the opportunity to share with you some of my convictions, anxieties, and hopes. My central conviction is the immense value of a mental outlook which can be called by the suggestive and historically recognized name Enlightenment, whose exact characterization, however, requires careful discussion. It is an outlook widely shared, though with innumerable personal variations, by the members of the Philosophy of Science Association, by the broader community of scientists, science teachers, and philosophers, and by an ill-defined part of the general public. My anxieties are that the cultivation and the influence of this mental outlook in our nation and in the world are threatened in various ways, among them ideological attacks, slackening of educational standards, and demoralization of its adherents. My central hope is that Enlightenment will prevail despite these threats.

In addition to its obvious successes within the kinetic theory the ideal gas law and the modeling assumptions associated with it have been used to treat phenomena in domains as diverse as economics and biology. One reason for this is that it is useful to model these systems using aggregates and statistical relationships. The issue I deal with here is the way R. A. Fisher used the model of an ideal gas as a methodological device for examining the causal role of selection in producing variation in Mendelian populations. The model enabled him to create the kind of population where one could measure the effects of selection in a way that could not be done empirically. Consequently we are able to see how the model of an ideal gas was transformed into a biological model that functioned as an instrument for both investigating nature and developing a new theory of genetics.