Radical Behaviorism makes the implausible claim that “the appeal to mind explains nothing at all” (Skinner 1971, p. 186). Clearly, such a claim (if accepted) would lend strong support to the Skinnerian research program, if only because it would eliminate the major competition. But what support remains when such a claim is not accepted? This paper shall argue that the Skinnerian research program need not depend upon the supposition that there is something scientifically illicit or vacuous about the explanations offered by mentalistic psychology. Distinguishing Radical Behaviorism from a position that grows out of Skinner’s writings from 1938 through 1950, it asserts that the latter position provides a conception of the behavior analytic program that is compatible with the basic claims of cognitive and folk psychology.

We may give a rough definition of this position by following Cummins (1983) in distinguishing between two types of scientific theory.

My eyes are notoriously bad, so I am not sure whether I have ever seen a meteor. Others have seen them, of course, but it is important to me to observe them first hand. I even go to the trouble to hike at night in the desert mountains so that viewing conditions will be ideal. I scan the sky through my thick glasses, but to no avail. My companions have sighted several, the latest just to the left of that peak. And still I am unsure. Did I really see the meteor, or was it just that my eye twitched? I suspect that this question has no unambiguous answer and that understanding why it lacks such an answer will provide important clues about the role of observation in scientific theorizing.

A central aspect of the computational theory of vision developed by Marr and his coworkers is the use made of contingent regularities in the physical environment to explain how the visual system determines the shape and location of objects in the world on the basis of the spatial organization of the retinal image. Marr (1982) refers to these environmental regularities as “natural constraints” and “physical assumptions.” In this paper I am concerned with recent arguments concerning the implications of this feature of Marr’s theory for understanding psychological explanation. Burge (1986) claims that Marr’s use of natural constraints shows the theory to be nonindividualistic, in the sense that the individuation of psychological states depends essentially on the objects and conditions of the world external to the subject. While it does capture an important aspect of Marr’s theory, Burge’s account is misleadingly incomplete. To see this it is useful to compare the issue of individualism with the question whether the theory is compatible with methodological solipsism as a research strategy.

Some may find an oxymoron in my title. But, my use of “instrumental” is to focus attention on the real instruments of science-pumps, dynamos and cyclotrons-and not the view that scientific theories are best understood as instruments. In what follows I characterize and argue for a kind of realism strongly wedded to what we do with scientific instruments, and divorced from what our theories may say about the entities manipulated by these instruments. My discussion owes much to Ian Hacking’s “Experimental Argument for Realism” (Hacking 1983, ch. 16).

The following fantasy might help give some idea of the view I am interested in. Suppose that the diskettes, which many people use in conjunction with a small computer, do not store information magnetically; in fact they store it “radioactively,” exactly how, is not relevant. IBM decided that many people in their target personal computer market would be put off by “nuclear diskettes.”

Van Fraassen stresses two distinct but interrelated themes in The Scientific Image: the semantic view of theories and the epistemic status of unobservables. The first of these could easily be accepted by a scientific realist, and indeed realists like Giere have already adapted it to their purposes. So the specifically empiricist thread in van Fraassen’s philosophy stems from the second.

Van Fraassen breaks from tradition in founding his empiricism not on the ontological status of unobservable entities but on the epistemic attitude we take to them. The main points of his position are these:

1. 1) The claims of scientific theories, including claims about unobservable entities, are to be taken literally. Theories are not reconstructed so as to remove claims of the existence of unobservable objects.

2. 2) Observation is a matter of direct observation by accepted participants in the human scientific community.

The ability to observe is the ability to reliably detect, but that is not all observation is. A thermometer reliably detects temperature yet does not observe the temperature, whereas I do, even though in terms of reliability I cannot match the thermometer. An observation is detection accompanied by active classification and, typically, the subsequent formation of opinion. Even when we say of an animal that it can see something we mean more than that it reliably detects things of a certain sort but also that it deals with such things as objects, gauging their usefulness or lack thereof in relation to its interests and to other aspects of the world. This crucial addendum to the notion of observation can be enshrined in slogan: observers are potential believers. This marks the difference between mere detecting mechanisms and observers.

The contemporary scientific anti-realism of one such as van Fraassen, which is developed in detail under the label of “constructive empiricism” in van Fraassen (1980), can be characterized in terms of detecting mechanisms.

In “A Confutation of Convergent Realism,” Larry Laudan presents the realist with these fascinating challenges:

Not only do I fully endorse what Laudan says in these passages, I think it is time to take him up on these challenges.

Laudan’s position has been that scientific progress can be explained without having to appeal to verisimilitude. Instead, we explain the success of a scientific theory in terms of its subjugation to the cannons of experimental controls: those theories that have been put through proper testing during the course of their formulation are the ones that are most likely to be reliable. (1984, pp. 96-101)

Over the last eighteen years Manfred Eigen and his co-workers have postulated a new theory about the origin of life on earth that has presented a detailed account of how many of the features of extant living organisms (such as a universal genetic code and protein-nucleic acid interdependence) might have arisen from purely physical interactions.2 This theory is critically based on the special dynamical properties of certain chemical cycles called “hypercycles” which cause some of them to exhibit hyperbolic growth over time while undergoing selection. The purpose of this paper is to separate two aspects of this theory and then to study the first one in greater detail. The first aspect consists of a physical account of evolution by natural selection at the molecular level that depends only on the kinetics of certain chemical systems and can be applied to a variety of such systems. The second consists of the special dynamical properties that are exhibited when this account is applied, specifically, to hypercycles.

Sustained controversy over a philosophical issue is often times symptomatic of differing commitments at a more fundamental philosophical level. I will argue that two current debates over the foundations of the theory of natural selection are cases in point. Alexander Rosenberg, at times together with Mary Williams, challenges what is becoming received orthodoxy about the foundations of this theory. He argues that the currently popular propensity interpretation of fitness does not legitimize explanations in terms of natural selection, and that furthermore, the biological fields which typically study the ways in which selection pressures originate in the organism/environment complex are not in fact part of the theory of natural selection at all. His foils in the first case are Robert Brandon, John Beatty and Susan Mills;2 on the second issue he is engaged in debate with Elliott Sober.3 We will see that, although the controversies are ostensibly about the interpretation of fitness, the issues, at bottom, involve the nature of scientific explanation.

The issue of whether species are individuals is now an old one; the literature abounds with arguments, counter-arguments and counter-counter-arguments for their individuality. The question I want to take up in this paper is not whether species are indeed individuals, but what ramifications their alleged individuality has for macroevolutionary theory.

According to those biologists who argue for a new theory of macroevolution, the individuality of species is one of the fundamental premises of that theory. For example, Joel Cracraft writes of himself and others that

Although generally informed by an intimate knowledge of evolutionary biology and taxonomy, the controversy over the nature of species is clearly philosophical; it consists almost entirely of the clarification of old, and the invention of new arguments for or against calling the species category a class, The debate seems firmly divided between those, like Kitts and Bernier, who see homo sapiens as a class, and those, like Hull and Ghiselin, who see it as an individual. In the first case, particular human beings are members; in the second case, parts. To the champions of class, the essentialists, each species can be defined by means of a unique set of necessary and sufficient conditions, and every organism can be placed without equivocation into a particular species. To the individualists, nothing could be further from the truth. As a contingent, product of evolution, each species shares that crucial characteristic of an individual, spacio-temporal identity; each is a chunk of genealogical nexus.

In earlier publications Jaakko Hintikka has introduced the interrogative model of inquiry and studied some of its applications.1 At its simplest, the interrogative model takes the form of a game between a player known as the Inquirer and a source of information we call Nature. The inquirer is trying to derive a conclusion C from a given set of premises T by standard deductive means augmented by additional information gained from Nature. (We can think of C as a set of formulas related disjunctively to each other.) The inquirer may obtain this additional information by means of questions put to Nature. The answers to these questions, when available, are then added to the premise set T. When a question is answerable but no true answer is available, Nature may respond with a false answer.

The deductive steps employed are subject to certain limitations. For instance, if the derivation is being carried out in a Beth-style tableau system, we require that the deductive steps obey the subformula principle.2

Logical analyses of scientific representations of the world have usually focused on axiomatized or axiomatizable theories. As practiced, science seldom employs such theories. Rather, we find aggregations of claims, the logical relations of which are not as neat as philosophers of science might like them to be. Indeed, a common feature of such aggregations is the presence of certain “theoretical anomalies,” statements that are in some way incompatible with the remainder of the corpus. Huygens’ description of light as exhibiting an asymmetry with respect to its direction of propagation in polarization phenomena was such an anomaly because of its inconsistency with his account of light as longitudinal waves in a medium. (See Sabra 1981, pp. 226-227.) Although the occurrence of these anomalies is indicative of a problem that must be dealt with, inconsistent representations of the world are not without significant heuristic value.

Suppose you attend a seminar where a mathematician presents a proof to some of his colleagues. Suppose further that what he is proving is an important mathematical statement Now the following happens: as the mathematician proceeds, his audience is amazed at first, then becomes angry and finally ends up disturbing the lecture (some walk out, some laugh, …). If in addition, you see that the proof he is presenting is formally speaking (nearly) correct, would you say you are witnessing an extraordinary event in urgent need of explanation? Surely, your answer would be yes. But do events of this type actually occur? The matter of the fact is, yes, they do. This paper presents the details of such an event, suggests a possible explanation and examines its implications for our understanding of mathematical practice.

Although statistical techniques like regression analysis and path analysis are widely used in the biomedical, behavioral and social sciences to make causal inferences there has been surprisingly little philosophical discussion of the details of such techniques and of the conceptions of causation and explanation implicit in them. There also has been relatively little attempt to compare such techniques with various probabilistic models of causation and explanation in the philosophical literature.

In this paper I explore, for reasons of space in a very sketchy and schematic way, some issues in philosophy of science raised by regression analysis. One general conclusion I reach is that it is considerably less obvious than one might suppose that the philosophical theories alluded to above are plausibly viewed as reconstructions of regression techniques.

It is widely believed that if a piece of evidence for a theory was known at the time the theory was proposed, then it does not confirm the theory as strongly as it would if the evidence had been discovered after the theory was proposed. I shall call this view the predictivist thesis. Those who have endorsed it include Leibniz (1678), Huygens (1690, preface), Whewell (1847 vol. 2, p. 64f.), Peirce (1883), Duhem (1914, ch. II, §5), Popper (1965, p. 241f.), Lakatos (1970, p. 123), and Kuhn (1977, p. 322). On the other hand, the thesis has been rejected by a number of philosophers, including Mill (1872 bk. III, ch. 14, §6), Keynes (1921, p. 305), Rosenkrantz (1977, p. 169f.), Horwich (1982, pp. 108-117) and Schlesinger (1987). Others, while not rejecting the predictivist thesis, nevertheless regard the justification of the thesis as problematic; these include Hempel (1966, p. 38) and Gardner (1982).

In his recent book Foundations of Space-Time Theories Michael Friedman argues for a realism about theoretical structure based on specific methodological practices concerning theory unification. Theoretical structures that are essential to the unifying process are to be given a literal realistic interpretation while the remaining ones can be considered as having merely representational status. Friedman’s account of unification involves the notion of a literal reduction or identification of observational properties of entities or objects with their theoretical counterparts. The relationship between these two levels of theory can be construed as that of submodel to model. Once the appropriate reductions are achieved we are then free to conjoin certain theoretical structures with others thereby enabling us, over time, to produce a unified theory encompassing a variety of domains.

The alternative to this view Friedman describes as the representationalist approach. Instead of characterizing the relationship between observational and theoretical structures as that of submodel to model the observational properties are simply correlated by way of an embedding (as opposed to an identity) map with their appropriate theoretical counterparts.

In several recent papers, Arthur Fine has developed a far-reaching attack upon both the standard realist interpretations of science and their most prominent anti-realist alternatives (1986a, 1986b, 1986c). In their place, Fine proposes not another position on the realist/anti-realist axis, but an attitude toward science, the “natural ontological attitude” (NOA), which is supposed to remove any felt need for a philosophical interpretation of science.

In this paper I will be concerned with Fine’s reasons for adopting NOA rather than his arguments against realism and anti-realism. Unless these reasons are adequate, Fine’s papers are likely to set off a scramble for new and better arguments concerning realism, rather than the reorientation of the philosophy of science which his polemics are clearly intended to provoke. Thus for my purposes, we can presume that Fine’s criticisms of standard positions are generally sound. The question is whether Fine’s proposed alternative attitude can then satisfy the same argumentative standards.

Ludwik Fleck’s Genesis and Development of a Scientific Fact is an extended argument for the inclusion of social factors in the history and philosophy of science. Fleck uses the history of syphilis as his case study, which falls into two parts. In the first two chapters of his book, Fleck presents a history of the change of the concept of syphilis as a “carnal scourge with strong moralistic connotations” in the middle ages to the modern concept of syphilis as an infectious disease (1979, 77). In the second part of the book, he presents a detailed account of the development of a serum test for syphilis, the Wasserman reaction. Fleck also argues that perception is theory-laden, for example, in his comparative study of anatomical drawings, and for the importance of social pressures on the development of science, for example, in his discussion of the rivalry between nations to first develop a cure for syphilis, as demanded by politicians (1979, 133 ff. and 68).

Philosophers of science, e.g. Cartwright (1979) and Skyrms (1980), have given accounts of general causation in probabilistic terms; not surprising since we often accept general causal sentences as true despite being aware of apparent counterinstances. Consider:

(E1) Smoking is a cause of heart attacks.

We accept (E1) as true though aware of smokers who never have a heart attack. Here I quickly review familiar problems in two existing probabilistic accounts, offer a new objection, and suggest the beginnings of an alternative account.

The traditional model of general causation maintains that causes, and only causes, raise the probability of the effect That is:

(TM) F is a cause of G if and only if .

Despite some intuitive appeal, the traditional model faces at least three basic objections. First, consider cases of epiphenomena in which there are properties F, G, and H such that F is a cause of G, F is a cause of H, but G is not a cause of H and H is not a cause of G.