Recently, biologists and computer scientists who advocate the “strong thesis of artificial life” have argued that the distinction between life and nonlife is important and that certain computer software entities could be alive in the same sense as biological entities. These arguments have been challenged by Sober (1991). I address some of the questions about the rational reconstruction of biology that are suggested by these arguments: What is the relation between life and the “signs of life”? What work (if any) might the concept of “life” (over and above the “signs of life”) perform in biology? What turns on scientific disputes over the utility of this concept? To defend my answers to these questions, I compare “life” to certain other concepts used in science, and I examine historical episodes in which an entity's vitality was invoked to explain certain phenomena. I try to understand how these explanations could be illuminating even though they are not accompanied by any reductive definition of “life.”

Although most philosophers are not aware of it, research in cognitive development and in learning in the last decade has made considerable use of the characterizations of the nature and development of scientific knowledge proffered by philosophers of science. In a “reflexive” move, Alison Gopnik proposes philosophers of science can profit from the research of psychologists investigating cognitive development-specifically from that group of researchers who advocate the “theory theory.”

Recent controversy over the existence of biological laws raises questions about the cognitive aims of theoretical modeling in that science. If there are no laws for successful theoretical models to approximate, then what is it that successful theories do? One response is to regard theoretical models as tools. But this instrumental reading cannot accommodate the explanatory role that theories are supposed to play. Yet accommodating the explanatory function, as articulated by Brandon and Sober for example, seems to involve us once again in a reliance on laws. The paper concludes that we must rethink both the nature of laws and theoretical explanation in biology.

The supervenience and multiple realizability of biological properties have been invoked to support a disunified picture of the biological sciences. I argue that supervenience does not capture the relation between fitness and an organism's physical properties. The actual relation is one of causal dependence and is, therefore, amenable to causal explanation. A case from optimality theory is presented and interpreted as a microreductive explanation of fitness difference. Such micro-reductions can have considerable scope. Implications are discussed for reductive physicalism in evolutionary biology and for the unity of science.

Peter Lipton has attempted to flesh out a model of Inference to the Best Explanation (IBE) by clarifying explanation in terms of a causal model. But Lipton's account of explanation makes an adequate explanation depend on a principle which is virtually identical to Mill's Method of Difference. This has the result of collapsing IBE on Lipton's account of it into causal inference as conceived by the Causal-Inference model of induction. According to this model, many of our inductions are inferences from effects to their probable causes, and Mill's Methods are canons to guide such inferences. Thus, Lipton's account of IBE fails to represent an advance over the already familiar Causal-Inference Model of induction.

In this paper I provide a novel argument against the claim that classical genetics is being reduced to molecular genetics. Specifically, I demonstrate that reductionists must subscribe to the unargued and problematic thesis that molecular genetics is ‘independent’ of classical genetics. I also argue that several standard antireductionist positions can be faulted for unnecessarily conceding the Independence Thesis to the reductionists. In place of a ‘tale of two sciences’, I offer a ‘heroic’ stance that denies classical genetics is being reduced, yet sees classical and molecular genetics as fundamentally unified.

In Warrant and Proper Function, Alvin Plantinga claims that metaphysical naturalism, when joined to a naturalized epistemology, is self-undermining. Plantinga argues that naturalists are committed to a neoDarwinian account of our origins, and that the reliability of our cognitive faculties is improbable or unknown relative to that theory. If the theory is true, then we are in no position to know that, whereas theism, if true, underwrites cognitive reliability. I seek to turn the tables on Plantinga, showing that neoDarwinism provides strong reasons for expecting general cognitive reliability, whereas the likelihood of that relative to theism is unknowable.

This note aims to make more familiar to philosophers yet another bizarre quantum mechanical effect with disturbing metaphysical implications. It is possible to modify the classic double-slit experiment so that one can register the path of a particle to determine which slit it passes through, and then erase this registered information so that the interference effects which would normally disappear upon registration of the “which path” information are reconstituted. Thus the “trajectory” of particles can be effected by temporally and spatially distant operations on the slit detectors. Nonetheless, no untoward effects (such as superluminal signalling) can result from the operation of the eraser.

Recent work in the Philosophy of Mind has suggested that alternatives to reduction are required in order to explain the relationship between psychology and biology or physics. Emergence has been proposed as one such alternative. In this paper, I propose a precise definition of emergence, and I argue that chaotic systems provide concrete examples of properties that meet this definition. In particular, I suggest that being in the basin of attraction of a strange attractor is an emergent property of any chaotic nonlinear dynamical system. This shows that non-reductive accounts of inter-theoretic relations are necessary, and that non-reductive accounts of the mental are possible. Moreover, this work provides a foundation for future work investigating the nature of explanation, prediction, and scientific understanding of non-reductive phenomena.

An examination of the foundations of Elliot Sober's philosophy of biology as reflected in his introductory textbook of that title reveals substantial and controversial philosphical commitments. Among these are the claim that all understanding is historical, the assertion that there are biological laws but they are necessary truths, the view that the fundamental theory in biology is a narrative, and the suggestion that biology adverts to ungrounded probablistic propensities of the sort to be met with elsewhere only in quantum mechanics.

Although there has been some discussion in the literature of Bas van Fraassen's modal interpretation of Quantum Mechanics, it has for the most part been concentrated on difficulties that van Fraassen's viewpoint shares with those of some other authors, including Kochen, Dieks, and Healey. van Fraassen's approach has, however, some problems of its own; in this note we want to focus on what seems to us to be one of the most serious of these. The difficulty concerns immediately repeated non-disturbing measurements of the same observable on a single system. As is well known, von Neumann's Projection Postulate guarantees that such measurements will always give the same outcome; likewise, in the approaches of the “modalists” mentioned above, such ‘consilience of repeated measurements’ is in one way or another built into the formalism. By contrast, we shall argue, van Fraassen's modal interpretation neither guarantees this result nor adequately explains why it is unnecessary to do so.

I analyze a number of widespread misconceptions concerning species. The species category, defined by a concept, denotes the rank of a species taxon in the Linnaean hierarchy. Biological species are reproducing isolated from each other, which protects the integrity of their genotypes. Degree of morphological difference is not an appropriate species definition. Unequal rates of evolution of different characters and lack of information on the mating potential of isolated populations are the major difficulties in the demarcation of species taxa.

Newton's methodology emphasized propositions “inferred from phenomena.” These rest on systematic dependencies that make phenomena measure theoretical parameters. We consider the inferences supporting Newton's inductive argument that gravitation is proportional to inertial mass. We argue that the support provided by these systematic dependencies is much stronger than that provided by bootstrap confirmation; this kind of support thus avoids some of the major objections against bootstrapping. Finally we examine how contemporary testing of equivalence principles exemplifies this Newtonian methodological theme.

Once upon a time in evolutionary theory, everything happened for the best. Predators killed only the old or the sick. Pecking orders and other dominance hierarchies minimized wasteful conflict within the group. Male displays ensured that only the best and the fittest had mates. In the culmination of this tradition, Wynne-Edwards (1962, 1986) argued that many species have mechanisms that ensure groups do not over-exploit their resource base. The “central function” of territoriality in birds and other higher animals is “of limiting the numbers of occupants per unit area of habitat” (1986, 6). Species with dominance hierarchies, species with lekking breeding systems, and species with communal breeding regulate their populations. These social mechanisms have population regulation as their “underlying primary function” (1986, 9). Wynne-Edwards argued that these mechanisms evolve through group selection. Populations without such mechanisms are apt to go extinct by eroding their own resource base.

Owens (1993) argues that one cannot accept the anti-individualistic conclusions of arguments inspired by Twin Earth thought experiments and still maintain that folk psychological states causally explain behavior. Saidel (1994) has argued that Owens' argument illegitimately individuates the contents of folk psychological states widely and causal powers narrowly. He suggests that causal powers may well be wide, and that the conditions that militate in favor of wide content also militate in favor of wide causal powers; mutatis mutandis for narrow content and narrow causal powers. I argue that these suggestions are in error, and hence that Saidel's criticism is ineffective. Owens' original point is therefore likely to stand.

After some background setting in which it is shown how Maudlin's (1989, 1990) response to the hole argument of Earman and Norton (1987) is related to that of Rynasiewicz (1994), it is argued that the syntactic proposals of Mundy (1992) and of Leeds (1995), which claim to dismiss the hole argument as an uninteresting blunder, are inadequate. This leads to a discussion of how the responses of Maudlin and Rynasiewicz relate to issues about gauge freedom and relativity principles.

Biographical studies have shown that visual mental imagery plays a significant role in the conduct of scientific research, particularly in the generation of hypotheses. But the nature of visual mental imagery and its participation in abductive inference is not systematically understood. This paper discusses examples of visual abductive reasoning by archaeologists, analyzing them according to the visual information and the process of inference employed. This work supports the conclusion that visual abduction is useful to scientists under certain conditions and that it is amenable to detailed study.

I am grateful to Philip Kitcher for inviting me to comment on Alexander Rosenberg's (1996) review of Philosophy of Biology (Sober 1993) and to Rosenberg for his kind words about my book at the very beginning and the very end of his review. However, I cannot help feeling that most of the material in Rosenberg's review describes a different book from the one I wrote. Of the four philosophical claims that he ascribes to me, only one of them is asserted or implied in Philosophy of Biology. Rosenberg is right that I have argued that many evolutionary laws turn out, when stated carefully, to be a priori mathematical truths. However, he is mistaken in thinking that I am a “historicist” who holds that “fundamental theory in biology is narrative.” Rosenberg also misconstrues my views on the meaning of probability statements in evolutionary theory.