A presidential address provides a rare opportunity for public, disciplinary self-reflection. This is particularly true in the context of a joint meeting with related disciplines. Accordingly, rather than simply presenting my own view of science, I shall focus on those of us engaged in viewing science, particularly philosophers, psychologists, historians, and sociologists of science. I will, of course, be doing the viewing From the vantage point of the philosophy of science, which thus fills the foreground. The middle distance will be occupied by the sociology of science, while the history of science and cognitive studies of science occupy the background.

I begin with a historical view of the philosophy of science itself. The most common picture of the recent history of the philosophy of science in North America is that, after a long period of dominance, Logical Empiricism was superseded in the 1960s by an historical approach to the philosophy of science inspired by Kuhn's (1962) Structure of Scientific Revolutions.

The spirit of the papers that follow, reflecting the title of the original symposium, is to treat the philosophy of psychology as a branch of the philosophy of science. As such, philosophy of psychology is to be conceived on a parallel with philosophy of physics and philosophy of biology, as an instance of the “philosophy of the special sciences.” The philosophy of the special sciences treats each of the sciences as potentially having its own explanatory structures, conceptual problems, and evidentiary relations, which may be more or less similar to those once discussed under “general philosophy of science,” with its typical reliance on examples from physics. In this connection, work in the philosophy of psychology over the past two decades has analyzed the structure of psychological explanations (Cummins 1983; Hardcastle 1992; Haugeland 1978), has examined the conceptual issues attending such notions as that of representation (Dretske 1981; Hatfield 1988b; Lloyd 1989; Shapiro 1993) or qualitative experiential content (Dennett 1991; Hardin 1988), and has examined the theoretical structure and explanatory possibilities of the new connectionism (Horgan and Tienson 1991; Ramsey et al. 1991).

Philosophers of science have much to say that could be useful to philosophers of mind, especially naturalistic philosophers of psychology. We should listen. In particular, I believe that if philosophers of mind were clearer on how explanations function in science in general, then many of their present worries would either dissolve or be altered beyond recognition. In what follows, I show you what I mean.

First, though, I shall spend a few moments recapitulating the semantic view of theories and how it applies to psychology. This section will be fairly brief since details have already been presented elsewhere (see esp. Bickle 1993). However, let me emphasize at the outset that I am not adopting the semantic view because I think it is inherently superior to the more traditional models (though I do). Indeed, everything that I claim can be translated into any view of theory you might have with greater or lesser ease.

There are many different kinds of psychology: abnormal, behavioral, clinical, cognitive, developmental, physiological, personality, and social, to name some of the major categories. In recent years, philosophers of psychology (in the sense under discussion today) have focused primarily on cognitive psychology and Freudian psychoanalysis (which cross-cuts abnormal and personality). In this paper, I propose to turn my attention to one of the least discussed of these fields: social psychology. Specifically, I will consider a debate currently raging in the sub-field of social psychology known as “social perception research.”

Social psychology is - to quote from a recent textbook - “the scientific study of the thoughts, actions, and interactions of individuals as affected by the actual, implied, or imagined presence of others…. The social emphasis distinguishes social psychology from [other fields of] psychology, and the emphasis on the individual distinguishes it from sociology” (Tedeschi, Lindskold, and Rosenfeld 1985, 4-5).

Gustav Fechner published his monumental Elemente der Psychophysik in 1860. In the years to follow the book became the object of such intense criticism and such caustic invective that Fechner, prophetically, observed: “The tower of Babel was never finished because the workers could not reach an understanding on how they should build it; my psychophysical edifice will stand because the workers will never agree on how to tear it down” (Stevens 1957, 153). Fechner was right. Here we are, 134 years later, and psychophysics is still with us. Moreover, if it's true that psychophysics thrives on disagreement then likely it will be around for another millennium, for there is currently even less accord about what psychophysics is and whether it is possible than there was when Fechner was alive. Some psychophysicists retain Fechner's view of psychophysics and so claim to be searching for laws relating our sensory experience of the world to physical magnitudes in the world.

In November of 1925 Born, Heisenberg and Jordan wrote an article together in which they demonstrated that Einstein's energy fluctuation formula could be derived from quantum mechanics. They remark that the equations are subject to reinterpretation. Specifically, the states of radiation oscillators can be reinterpreted as numbers of quanta of radiation. They also connected this latter idea up with Bose-Einstein statistics. Heisenberg wrote to Pauli that it was Jordan who contributed the idea of reinterpreting the terms. This was the first step toward quantum field theory. In August of the following year Dirac derived Einstein's A and B coefficients for induced transitions between states but on the assumption that the electromagnetic field could be treated classically (Dirac 1927). In 1927 Dirac lay the mathematical foundations for quantum electrodynamics. Early that year he combined quantum mechanics, special relativity, and radiation theory in treating the electromagnetic field as if it were an infinite collection of oscillators.

There is an emerging story about many particle quantum mechanics (MPQM) and quantum field theory (QFT) based partly on views inherited from physics, and partly on new work, especially that of Paul Teller and Michael Redhead. Three important steps in the tale go like this—(a) The transition from classical mechanics (CM) to quantum mechanics (QM) involves a significant change in particle metaphysics, (b) QFT cannot be viewed as particulate even in a MPQM sense, although (c) an ontologically enlightening understanding of QFT can be obtained from the occupation representation. Though there is some truth to all of these claims, I wish to argue that, as usually understood, they are in fact false.

The ever present danger in metaphysical debates such as these is that participants will be running around on the same pitch but playing different games; some waving cricket bats at the ball, some aiming for a netball hoop and others trying for a touch-down.

Intuitively the vacuum state of the Universe is the state that would obtain if the spacetime arena were emptied of its contents. The idea is that if we removed all the material particles, such as quarks and electrons, together with all the force-carrying particles such as photons and gluons, so there was no matter or force in the Universe, then we would be left with a featureless space-time, the bare arena of physics, and this would be the vacuum.

There are many reasons why such an idea is problematic. On a strict relationist conception of space-time, the procedure envisaged would leave us, not with empty spacetime, but literally with nothing. Having removed the relata, the spatio-temporal relations would also disappear. This problem does not arise for space-time substantivalists, but general relativity now raises difficulties.

Relativistic quantum theory poses a number of conceptual problems over and above the non-relativistic mechanics. From a purely mathematical point of view it is also much more sophisticated. Even the kinematic theory poses considerable difficulties: locality, antimatter, negative energy, and charge are already systematically linked in ways that cannot simply be paraphrased. A further complication is that in the midst of this structure we have what is usually called the Newton-Wigner representation (or, in the case of the Dirac theory, the Foldy-Wouthuysen representation), in which fields and states are no longer covariantly described and where the “local” self-adjoint quantities (NW-local observables) do not obey microcausality, but only satisfy equal-time commutators with respect to a particular inertial frame. If we pass to this represenation, we obtain at a stroke the basic structure of non-relativistic quantum field theory; it is not too hard to descend from that to a many-particle mechanics, and to recover the usual definitions of localization.

This essay explores one of the fundamental ways in which feminist methodology in philosophy of science differs from most standard philosophy of science. Methodology in general arises from goals which the methods are designed to reach. Feminist goals in philosophy have been scandalous precisely because they are avowed political interventions into what has been considered a cool, apolitical academic activity. Another way to put this point is that feminism self-consciously inserts certain moral and political values into an activity considered to be neutral among moral and political values; it advocates a moral and political point of view in an area presumed to be objective in the sense that it is without any point of view. And precisely because the goals of feminist efforts in philosophy of science are moral and political ones, they appear inimical to the central goals of philosophy of science itself—the morally neutral and apolitical production of theories about how science works.

There are many reasons why my “special science,” psychology—and more specifically cognitive psychology—lends itself to particularly fruitful feminist philosophical analysis. Many central questions in feminist philosophy of science and feminist science studies are well illuminated there, especially those that are reflected in specific methodological issues. For example, in feminist science critiques tensions have arisen about the role of empiricism: many stress the importance of paying careful attention to certain strictures of empiricist methodology (close attention to accuracy in data collection, hypothesis formation, replication of “findings” about sex differences, and so on), yet concerns have also been raised about empiricism as an overall feminist epistemological framework—specifically, concerns about whether such a framework can adequately entertain the most transformative feminist political projects. I think such tensions in feminist science criticism are best addressed by paying close attention to their deployment in particular working contexts of feminist science.

Commonly-cited criteria for the assessment of hypotheses, research projects, and theories include empirical adequacy, simplicity, conservatism, explanatory power, generality of scope, fecundity, reproducibility, and interconnectedness with other going theories. The list of criteria for good scientific practice typically includes objectivity (though what objectivity comes to is much disputed), respect for evidence, open mindedness, and tentativeness. Feminist scientists and science scholars have of late proposed additional and, in some cases, alternative criteria (e.g., Biology and Gender Study Group 1989, Bleier 1984, Fausto-Sterling 1985, Haraway 1978, Keller 1983 and 1985, Longino 1994, and Nelson 1990). We here consider the nature and rationale of some of these proposed criteria, focusing on several articulated by Helen Longino. A research program in neuroendocrinology investigating a hormonal basis for alleged sex-differentiated lateralization and feminist critiques of this research serve as our case study.

Why do scientists accept or reject theories? More specifically: why do they change from one theory to another? What is the role of empirical tests in the evaluation of theories?

This paper focuses on a narrowly-defined question: in judging theories, do scientists give greater weight (other things being equal) to successful novel predictions than to successful deductions of previously-known facts? The affirmative answer is called the “predictivist thesis” (Maher 1988).

It is primarily philosophers who are interested in this question, and they have treated it mostly as a normative or logical problem. Can the writings of historians of science tell us how scientists have treated novel predictions in the past? Until recently historians have rarely addressed this point.

A common device in popular presentations of science is a sequence of views from cosmic to terrestrial to local to microscopic, thereby placing the subject to which the program is devoted in a proper perspective. I wish to use an adaptation of this device to place the announced topic of our panel — “Do Explanations or Predictions Provide More Evidential Support for Scientific Theories?” — in perspective. My four steps, from the largest to the smallest scale, are the following:

1. 1. A brief summary of the world view suggested by the discoveries of the natural sciences and by philosophical reflections on them;

2. 2. a consideration of the methodology for scientific investigation, upon assumption that this world view is approximately correct;

3. 3. the formulation of a version of Bayesian scientific inference satisfying the desiderata of step 2;

4. 4. the topic of our panel — explanation vs. prediction.

According to a standard view, predictions of new phenomena provide stronger evidence for a theory than explanations of old ones. More guardedly, a theory that predicts phenomena that did not prompt the initial formulation of that theory is better supported by those phenomena than is a theory by known phenomena that generated the theory in the first place. So say various philosophers of science, including William Whewell (1847) in the 19th century and Karl Popper (1959) in the 20th, to mention just two.

Stephen Brush takes issue with this on historical grounds. In a series of fascinating papers he argues that generally speaking scientists do not regard the fact that a theory predicts new phenomena, even ones of a kind totally different from those that prompted the theory in the first place, as providing better evidential support for that theory than is provided by already known facts explained by the theory.

The primary focus of philosophy of science in this century has been on theories and theoretical knowledge. Except for concern about whether phenomenal reports or reports of objects and events should count as data reports and whether data might be theory-laden and what consequences that might have for objectivity of science, data have been taken to be relatively unproblematic. But for scientists, questions about what are the data are often of paramount concern. Such controversies often overshadow controversies over theories or explanatory models. Scientists’ questions about data, moreover, do not turn on the philosophical questions just identified. Instead, for scientists, the overriding question is whether purported data is actually informative about the phenomenon in nature under investigation or whether it represents an artifact; that is, whether it was so much the product of the procedures used to generate the data that it could not be interpreted as providing information about the underlying phenomenon.

In the spring of 1994, Lindley Darden spent five months as a visitor in Joshua Lederberg's Laboratory for Molecular Genetics and Informatics (MGI) at Rockefeller University. Michael Cook is a Research Associate in the MGI Lab. This paper discusses reasoning strategies at use in that lab. In Part I, Lindley Darden recounts her experiences in the lab and discusses reasoning strategies that she observed in use there. In Part II, Michael Cook presents a technique of methodical hypothesis generation in the light of an anomaly for a model.

The reasoning strategies to be discussed in this paper are reasoning in hypothesis formation, reasoning in experimental design, and reasoning to generate hypotheses in the light of an anomaly. More specifically, the reasoning strategies may be characterized as (1) abstraction-instantiation (Darden, 1987; 1991; Darden and Cain, 1989), (2) the systematic scan (Lederberg, 1965), and (3) modular anomaly resolution (Darden, 1991; 1992; forthcoming).

In this paper, I revisit a problem in immunology and molecular genetics that I had first tried to understand some philosophical implications of over twenty years ago. At that time, some immunologists such as Mel Cohn at the Salk Institute, referred to it as the GOD problem, which was the acronym for Generator Of Diversity (also see Cohn's more recent discussion in his 1994, 41-48). In the early 1970s there were three or four different theories that had been proposed to account for the way in which antibody diversity is generated and considerable argument among the proponents of the different approaches to the problem (see Cohn, 1994). In 1971-72 I attempted to assess the strengths and weaknesses of the competing theories of antibody diversity from the perspective of a “logic of comparative theory evaluation” that had seemed to work reasonably well in physics (Schaffner, 1970), and I drafted an essay that ultimately sided with one of those theories (somatic mutation).