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history of the philosophy of science in North America is that, after a long period of dominance, Logical Empiricism was superseded in the 1960s by an historical approach to the philosophy of science inspired by Kuhn's (1962) Structure of Scientific Revolutions.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).

Since the mid-1970s, when philosophical scrutiny of biology began to be focused on evolutionary theory, the center of philosophical attention in that field has been what is called the “units of selection” controversy. In particular, two problems have attracted philosophical and, on occasion, biological attention: (i) should natural selection be regarded as capable of operating on groups of individuals as distinct units, or should such a process only be regarded as a special type of selection on the constituent individuals of such groups even when every member of the group, by virtue of its membership of that group, is affected by selection in an identical manner?; and (ii) similarly, should selection be regarded as “ultimately” operating only on individual alleles since, even when the genotype seems to feel the action of selection more directly, any change in the genotypic composition of a population also consists of a change in its allelic composition?

Within evolutionary ecology, there is a substantial tradition treating natural selection as an optimizing agent tending to produce maximal adaptedness to the environment. This includes the work of Sewall Wright and R.A. Fisher, as well as a number of influential modern defenders such as G.C. Williams, J.R. Krebs, Richard Levins, Robert MacArthur, E.O. Wilson, and John Maynard Smith. In one widely deployed class of models, the phenotype or behavior of organisms is predicted on the basis of optimization principles, assuming ”… that the organisms’ preferences are related to evolutionary fitness and that the options more prefeaed must lead to greater survival and reproduction” (Real and Caraco 1986, 371-2). Optimality is measured by some “currency,” or what Richard Lewontin (1987) calls a “criterion scale,” providing an independent operational measure of fitness.

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).

Imagine two theories in a scientific controversy cast as competing teams in the Super Bowl, and you may get a “Scoreboard of experimental evidence” such as the following, published in a review article in 1970 (after Racker 1970, 135):

This figure compares two hypotheses in a debate in bioenergetics in the 1960s and 70s known as the Ox-Phos Controversy (Rowen 1986; Allchin 1990; Weber 1991). But its format, suggested by its title, bears a striking resemblance to the half-time recaps in televised football games: parallel assessments in several categories ask us to compare, say, how many yards rushed, number of first downs, passes completed, evidence for the role of the membrane, or evidence for ion transport, etc. (see also Sindermann 1982). Why did the review author—Efraim Racker, a research biochemist—borrow the scoreboard framework from sports to convey his assessment in science?

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.

Many ecologists have questioned the status of proposed ecological “laws,” charging that they are devoid of empirical content and predictive power or that they are tautological, trivial, circular, or nontestable (Peters 1976, 1978,1991; Simberloff 1983, 1984; Simberloff and Boecklen 1981; Strong and Simberloff 1981; Strong and Levin 1979; see also Williams 1970; Ferguson 1976; Rosenberg 1978; Stebbins 1978; Caplan 1978; and Shrader-Frechette and McCoy 1990). As a result, a number of ecologists have urged their colleagues instead to “study … real organisms,” rather than worry about untestable theories and laws (Van Valen and Pitelka 1974, 925; Mclntosh 1982, 23).

In this essay we investigate the epistemological status of a prominent “ecological law” in order to gain insights about the characteristics of ecological explanation.

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.

In “Facts, Artifacts, and Mesosomes: Practicing Epistemology with the Electron Microscope” (1993), Nicolas Rasmussen presents an account of the mesosome, a bag-shaped membranous structure first observed by electron microscopists in grampositive bacteria, as a test case for robustness. Rasmussen argues that robustness as a criterion for the reality or artifactuality of experimental results fails this test; for, after 15 years of interpreting electron micrographs of specimens prepared by a variety of techniques as supporting evidence for the existence of mesosomes, electron microscopists ultimately concluded that mesosomes were an artifact produced by these preparation techniques. According to Rasmussen, electron microscopists did not use robustness to “decide reliably between conflicting observations” (ibid., 231). Moreover, Rasmussen also claims that research on mesosomes “resembles that of high flux gravity waves as described by Harry Collins, especially in the obviousness of ‘experimenter's regress’ or logical circularity entailed in the evaluation of experiments according to their results…“(ibid., 256).

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.

I hope to convince you that one way of testing the mettle of a theory of scientific explanation is to inquire what that theory entails about the status of brute facts. In what follows I briefly consider the nature of brute facts, and then survey several contemporary accounts of explanation vis a vis this subject. These include the Friedman-Kitcher theory of explanatory unification (Friedman (1974), Kitcher (1981) and (1989)), Peter Lipton's (1991) account of the nature of explanatory loveliness, and the causal theory of event explanation developed by Paul Humphreys in his (1989). It is my view that each of these accounts of explanation entails (or at least lends itself to) a false view about the nature of brute facts: according to each account, a brute fact is unexplainable and thus represents a scientific ‘mystery’, where by this expression I mean some manner of a lack of scientific understanding.

The premise of the present paper is the primacy of understanding over explanation. The question “is the act of explaining a goal in itself, or is it a means to an end?” is here answered by “explaining is a pragmatic concept and serves the purpose of responding credibly to a request for understanding.” Explaining is secondary, understanding is primary.

Given this view of scientific explanation, one is faced with the received view and the recent literature based on it. Models of explanation cast into the covering law format do not necessarily ensure understanding, nor do they necessarily provide sufficient information for credibility.

After explicating this dissatisfaction (Section 2) I shall first clarify what I mean by scientific theory, law, and model (Section 3) since these concepts are crucial for the covering theory model proposed in Section 4.

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.