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Reductionism is often understood to include two theses: (1) every singular occurrence that the special sciences can explain also can be explained by physics; (2) every law in a higher-level science can be explained by physics. These claims are widely supposed to have been refuted by the multiple realizability argument, formulated by Putnam (1967, 1975) and Fodor (1968, 1975). The present paper criticizes the argument and identifies a reductionistic thesis that follows from one of the argument's premises.

Critique de l'ouvrage de W. A. Dembsky intitule «L'inference du dessein» (198) qui examine les contextes non-theologiques de l'argument philosophique du dessein. L'A. rejette la methode epistemologique de Dembsky, fondee sur la hasard et la probabilite, qui ne rend pas compte de la these creationniste ni de la theorie evolutionniste de l'univers.

Physicalism -like other isms -has meant different things to different people. The main physicalistic thesis I will discuss here is the claim that all occurrences supervene on physical occurrences -that the physical events and states of affairs at a time determine everything that happens at that time. This synchronic claim has been discussed most in the context of the mind/body problem, but it is fruitful to consider as well how the supervenience thesis applies to what might be termed the organism/body problem. How are the biological properties of a system at a time related to its physical properties at that time?

An empirical procedure is suggested for testing a model that postulates variables that intervene between observed causes and observed effects against a model that includes no such postulate. The procedure is applied to two experiments in psychology. One involves a conditioning regimen that leads to response generalization; the other concerns the question of whether chimpanzees have a theory of mind.

In Chapter 12 of Warrant and Proper Function, Alvin Plantinga constructs two arguments against evolutionary naturalism, which he construes as a conjunction E&N. The hypothesis E says that “human cognitive faculties arose by way of the mechanisms to which contemporary evolutionary thought directs our attention” (p. 220). With respect to proposition N, Plantinga (p. 270) says “it isn't easy to say precisely what naturalism is,” but then adds that “crucial to metaphysical naturalism, of course, is the view that there is no such person as the God of traditional theism.” Plantinga tries to cast doubt on the conjunction E&N in two ways. His “preliminary argument” aims to show that the conjunction is probably false, given the fact (R) that our psychological mechanisms for forming beliefs about the world are generally reliable. His “main argument” aims to show that the conjunction E&N is self-defeating – if you believe E&N, then you should stop believing that conjunction. Plantinga further develops the main argument in his unpublished paper “Naturalism Defeated” (Plantinga 1994). We will try to show that both arguments contain serious errors.

John Beatty (1995) and Alexander Rosenberg (1994) have argued against the claim that there are laws in biology. Beatty's main reason is that evolution is a process full of contingency, but he also takes the existence of relative significance controversies in biology and the popularity of pluralistic approaches to a variety of evolutionary questions to be evidence for biology's lawlessness. Rosenberg's main argument appeals to the idea that biological properties supervene on large numbers of physical properties, but he also develops case studies of biological controversies to defend his thesis that biology is best understood as an instrumental discipline. The present paper assesses their arguments.

The six commentaries raise five issues about multi-level selection theory that we attempt to address: (1) replicators without vehicles, (2) group selection and movement between groups, (3) absolute versus relative fitness, (4) group-level psychological adaptions, and (5) multi-level selection as a predictive theory.

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.

If a parsimony criterion may be used to choose between theories that make different predictions, may the same criterion be used to choose between theories that are predictively equivalent? The work of the statistician H. Akaike (1973) is discussed in connection with this question. The results are applied to two examples in which parsimony has been invoked to choose between philosophical theories-Shoemaker's (1969) discussion of the possibility of time without change and the discussion by Smart (1959) and Brandt and Kim (1967) of mind/body dualism and the identity theory.

In the past few decades, sex differences in spatial cognition have often been attributed to adaptation in response to natural selection. A common explanation is that home range size differences between the sexes created different cognitive demands pertinent to wayfinding in each sex and resulted in the evolution of sex differences in spatial navigational ability in both humans and nonhuman mammals. However, the assumption of adaptation as the appropriate mode of explanation was nearly simultaneous with the discovery and subsequent verification of the male superiority effect, even without any substantive evidence establishing a causal role for adaptation. An alternate possibility that the sex difference in cognition is a genetic or hormonal side effect has not been rigorously tested using the comparative method. The present study directly evaluates how well the range hypothesis fits the available data on species differences in spatial ability by use of a phylogenetically based, cross-species, comparative analysis. We find no support for the hypothesis that species differences in home range size dimorphism are positively associated with parallel differences in spatial navigation abilities. The alternative hypothesis that sex differences in spatial cognition result as a hormonal side effect is better supported by the data.

Historical sciences like evolutionary biology reconstruct past events by using the traces that the past has bequeathed to the present. The Markov Chain Convergence Theorem and the Data Processing Inequality describe how the mutual information between present and past is affected by how much time there is in between. These two results are very general; they pertain to any process, not just to the biological processes that occur in evolution. To study the specifically biological question of how the present state of a lineage provides information about its evolutionary past, we use a Moran process framework and consider how the kind of evolutionary process (drift, and selection of various kinds) at work in a lineage affects the epistemological relation of present to past., 22 pages, 4 figures

The evolutionary problem of the units of selection has elicited a good deal of conceptual work from philosophers. We review this work to determine where the issues now stand.

L'A. etudie la question de l'augmentation de l'entropie dans un systeme thermodynamique, en reference a l'ouvrage de M. Barrett et E. Sober intitule «When and Why Does Entropy Increase?». Mesurant la probabilite de distribution d'energie dans un systeme physique, la seconde loi de thermodynamique souleve le probleme de l'asymetrie temporelle. L'entropie concerne le desordre ou l'incertitude liee a un ensemble n de causes dichotomiques provoquant un ensemble m d'effets dichotomiques

In both biology and the human sciences, social groups are sometimes treated as adaptive units whose organization cannot be reduced to individual interactions. This group-level view is opposed by a more individualistic one that treats social organization as a byproduct of self-interest. According to biologists, group-level adaptations can evolve only by a process of natural selection at the group level. Most biologists rejected group selection as an important evolutionary force during the 1960s and 1970s but a positive literature began to grow during the 1970s and is rapidly expanding today. We review this recent literature and its implications for human evolutionary biology. We show that the rejection of group selection was based on a misplaced emphasis on genes as “replicators” which is in fact irrelevant to the question of whether groups can be like individuals in their functional organization. The fundamental question is whether social groups and other higher-level entities can be “vehicles” of selection. When this elementary fact is recognized, group selection emerges as an important force in nature and what seem to be competing theories, such as kin selection and reciprocity, reappear as special cases of group selection. The result is a unified theory of natural selection that operates on a nested hierarchy of units.The vehicle-based theory makes it clear that group selection is an important force to consider in human evolution. Humans can facultatively span the full range from self-interested individuals to “organs” of group-level “organisms.” Human behavior not only reflects the balance between levels of selection but it can also alter the balance through the construction of social structures that have the effect of reducing fitness differences within groups, concentrating natural selection (and functional organization) at the group level. These social structures and the cognitive abilities that produce them allow group selection to be important even among large groups of unrelated individuals.

Traditional analyses of the curve fitting problem maintain that the data do not indicate what form the fitted curve should take. Rather, this issue is said to be settled by prior probabilities, by simplicity, or by a background theory. In this paper, we describe a result due to Akaike [1973], which shows how the data can underwrite an inference concerning the curve’s form based on an estimate of how predictively accurate it will be. We argue that this approach throws light on the theoretical virtues of parsimoniousness, unification, and non ad hocness, on the dispute about Bayesianism, and on empiricism and scientific realism.

The use of optimality models in the investigation of adaptation remains controversial. Critics charge that advocates of the optimality approach assume that the traits they analyze are optimal. Advocates of the approach deny this but admit to assuming that the traits have adaptive explanations. This controversy is part of the ongoing debate about adaptationism. We believe that this controversy remains unresolved in part because of ambiguity in the definition of adaptationism. In this article, we clarify the thesis of adaptationism, show how the structure of optimality models relates to that thesis, and describe how the thesis of adaptationism is testable. In addition, we describe the types of analyses that are essential to a test of an optimality model if the optimality of the trait is to be assessed and if assessments of the success of specific models are to contribute to a test of adaptationism. These analyses allow one to distinguish between the hypothesis that natural selection has had some influence o...

Suppose that several observations “coincide,” meaning that they are similar in some interesting respect. Is this coinciding a mere coincidence, or does it derive from a common cause? Those who reason about this kind of question—whether they embrace the first answer or the second—often deploy a mode of inference that I call probabilistic modus tollens. In this chapter I criticize probabilistic modus tollens and consider likelihood and Bayesian frameworks for reasoning about coincidences. I also consider the perspective offered by model selection theory (including the Akaike information criterion), and argue that model selection often provides important insights.

Publisher Summary Akaike helped to launch the field in statistics now known as model selection theory by describing a goal, proposing a criterion, and proving a theorem. The goal is to figure out how accurately models will predict new data when fitted to old. The criterion came to be called the Akaike Information Criterion (AIC). The theorem that Akaike proved made it natural to understand AIC as a frequentist construct. AIC is a device for estimating the predictive accuracy of models. Bayesians assess an estimator by determining whether the estimates it generates are probably true or probably close to the truth. This chapter shows that it is an estimator whose estimates should be taken seriously by Bayesians, its frequentist pedigree notwithstanding. Frequentists often maintain that the question of how an individual estimate should be interpreted is meaningless—that the only legitimate question concerns the long-term behavior of estimators. Bayesians prove that interpretation of individual estimates is pressing in view of the fact that a given estimate might be produced by any number of different estimation procedures.

Richard Levins's 1966 article "The strategy of model building in population biology" is an extremely influential analysis of the nature of scientific model building. His claims that model building involves a necessary trade-off among generality, realism and precision, and that truths about nature can be revealed by finding "robust theorems" are important and deserve careful scrutiny. We clarify the concepts of generality, realism and precision and argue that there is no necessary conflict among them. We also examine the idea of robustness and conclude that it lacks proper definition and that its bearing on the question of whether a proposition is true is highly problematic. Accordingly, we believe that neither of Levins's claims should be accepted.

A system whose expected state changes with time cannot have both a forward-directed translationally invariant probabilistic law and a backward-directed translationally invariant law. When faced with this choice, science seems to favor the former. An asymmetry between cause and effect may help to explain why temporally oriented laws are usually forward-directed.

Dans le debat scientifique entre realisme et empirisme, l'A. explique la position de Van Fraassen quant a son empirisme constructif. Il souleve differents problemes epistemologiques concernant le role des hypotheses et leur utilisation dans les sciences

Evolutionary theory is awash with probabilities. For example, natural selection is said to occur when there is variation in fitness, and fitness is standardly decomposed into two components, viability and fertility, each of which is understood probabilistically. With respect to viability, a fertilized egg is said to have a certain chance of surviving to reproductive age; with respect to fertility, an adult is said to have an expected number of offspring.1 There is more to evolutionary theory than the theory of natural selection, and here too one finds probabilistic concepts aplenty. When there is no selection, the theory of neutral evolution says that a gene’s chance of eventually reaching fixation is 1/(2N), where N is the number of organisms in the generation of the diploid population to which the gene belongs. The evolutionary consequences of mutation are likewise conceptualized in terms of the probability per unit time a gene has of changing from one state to another. The examples just mentioned are all “forward-directed” probabilities; they describe the probability of later events, conditional on earlier events. However, evolutionary theory also uses “backwards probabilities” that describe the probability of a cause conditional on its effects; for example, coalescence theory allows one to calculate the expected number of generations in the past that the genes in the present generation find their most recent common ancestor.

Hedonism is a species of egoism. Egoism holds that all of our ultimate desires are self-directed. Hedonism goes further; it says that our only ultimate desire is the self-directed desire for pleasure and the avoidance of pain. 1 Although psychological egoism is fundamental to every major school of twentieth century psychology,2 many philosophers believe that decisive objections have been developed against that position. My goal in this article is not to review these various philosophical arguments, but to focus on just one of them. Bishop Butler is widely regarded as having refuted hedonism. His argument is succinctly stated in the following passage: "That all particular appetites and passions are towards external things themselves, distinct from the pleasure arising from them, is manifested from hence; that there could not be this pleasure, were it not for that prior suitableness between the object and the passion: there could be no enjoyment or delight from one thing more than another, from eating food more than from swallowing a stone, if there were not an affection or appetite to one thing more than another."3 I'll call this argument "Butler's stone." Echoes of Butler's reasoning can be heard when subsequent philosophers explain why hedonism is mistaken. C. D. Broad claims that misers and "almost any keen politician" give the lie to hedonism, since they desire money and power even when these items conflict with the attainment of happiness. He then remarks

The idea that the changing entropy of a system is relevant to explaining why we know more about the system's past than about its future has been criticized on several fronts. This paper assesses the criticisms and clarifies the epistemology of the inference problem. It deploys a Markov process model to investigate the relationship between entropy and temporally asymmetric inference.

When does self-interest counsel cooperation? This question pertains both to the labile behaviors produced by rational deliberation and to the more instinctive and fixed behaviors produced by natural selection. In both cases, a standard starting point for the investigation is the one-shot prisoners' dilemma. In this game, each player has the option of producing one or the other of two behaviors (labeled “cooperate” and “defect”). The pay-offs to the row player are as follows

A simple and general criterion is derived for the evolution of altruism when individuals interact in pairs. It is argued that the treatment of this problem in kin selection theory and in game theory are special cases of this general criterion.

Brandon ([1982] 1984, 1990) has argued that Salmon's (1971) concept of screening-off can be used to characterize (i) the idea that natural selection acts directly on an organism's phenotype, only indirectly on its genotype, and (ii) the biological problem of the levels of selection. Brandon also suggests (iii) that screening-off events in a causal chain are better explanations than the events they screen off. This paper critically evaluates Brandon's proposals.

Like Darwin's own theory of evolution, the modern Darwinian theory of evolution has two main elements: “The Tree of Life: All organisms now alive on earth trace back to a common ancestor. / Natural Selection: Natural selection has been an important cause of the similarities and differences that exist in the earth's biota.” / The first of these propositions says that any two contemporary organisms have a common ancestor. Human beings are genealogically related to each other, but each human being also has a common ancestor with chimps, dogs, clams, daffodils, bacteria and yeast. The second proposition, as I have formulated it, does not say that natural selection is the only cause of evolution. Indeed, it should be understood to leave open the possibility that there are traits for which natural selection is entirely irrelevant. This is the big picture, and evolutionary biology is devoted to filling in the details. Although Darwinism is easy to describe, this simple theory gives rise to a rich range of metaphysical and epistemological questions. It is the purpose of this chapter to discuss some of them. In conformity with the structure of Darwinian theory, I have chosen one metaphysical and one epistemological problem from each of the two big ideas.

A model of a Markov process is presented in which observing the present state of a system is asymmetrically related to inferring the system's future and inferring its past. A likelihood inference about the system's past state, based on observing its present state, is justified no matter what the parameter values in the model happen to be. In contrast, a probability inference of the system's future state, based on observing its present state, requires further information about the parameter values.

For Batson and Shaw, altruism does not require self-sacrifice. One reason for separating these two features is that altruism is a property of motives, whereas self-sacrifice is a consequence of actions. I might have the altruistic intention of helping you even though my subsequent action happens to yield (unanticipated) benefits to me and so is not costly at all. The motive was altruistic, although the consequent action did not involve self-sacrifice. Batson and Shaw go further than this. Not only does altruism not require actual self-sacrifice; it also does not require the willingness to sacrifice one's self. Explaining this further implication of their definitions will help highlight what the empathy-altruism hypothesis actually says. I need to distinguish what I call the self-directed and the other-directed preferences an agent might have in some situation. A self-directed preference describes the situation of the agent, but not the situation of anyone else. An other-directed preference describes the situation of someone else, but not of the agent. An example of the first sort of preference would be my preferring that I have more money rather than less. An example of the second would be my preferring that you have more money rather than less. In addition to these two "pure" sorts of preferences, there also are mixed preferences, which describe the situations of both self and other; these can be left to one side. Agents decide which action to perform in a situation by seeing which of the available actions maximizes their preferences. For example, suppose you are contemplating whether to send a check for $25 to a charity. This action, you believe, will benefit malnourished children. It will cost you a modest amount of money. And there are the psychic consequences as well; you will think well of yourself and avoid feeling guilty. Suppose you send the check to the charity. The action you performed was the upshot of the various preferences you had. Perhaps you preferred that the children be better off rather than worse off; perhaps you also preferred that you feel good about yourself rather than bad. For simplicity, I ignore the other preferences you may have had (including the one about money), and focus on just these two possibilities. Note that one of them is other-directed, and the other is self-directed. There are four relationships that might obtain among these two possible preferences. They are depicted in Table 1. The numbers indicate a preference order; their absolute values have no significance. Individuals with the preference structure I call extreme egoism care only about themselves; the welfare of others does not matter to them at all. Symmetrically, people with the preference structure I call extreme altruism care only about others, not about themselves. Each of these structures says that people are motivated by a single kind of preference. Note that, when people face choices in which self-interest and the welfare of others coincide, they will perform the same action, regardless of whether they are extreme egoists or extreme altruists. When the choice is between the upper left and lower right cells, the agent will select the former (because 4 > 1). The other two structures depicted in Table 1 each say that people are motivated by two sorts of preferences. Moderate egoists and moderate altruists, as I call them, care both about themselves and about others. They differ when they face a choice situation in which self-interest and the welfare of others conflict. When the choice is between the upper right and lower left cells, a moderate egoist will place self-interest ahead of the welfare of others. A moderate altruist, in the same situation, will sacrifice self-interest for the sake of the other. Moderate and extreme egoists are not willing to sacrifice self for the sake of another. Moderate and extreme altruists are willing to do so. The difference between altruism and egoism, when defined in this way, does not concern whether people have other-directed preferences, but whether self or other matters more in the choice situation at hand (Sober, 1989). In describing these four preference structures, I do not assume that a person will have the same preference structure from one choice situation to another. Presumably, a person might be an altruist in one situation but an egoist in another. Nor does this framework assume that there is such a thing as "the altruistic personality." The personality factors that cause an individual to have a particular motivational structure, in a given circumstance, are left open. This way of thinking about altruism and egoism predicates those properties of motivational structures or of persons in choice situations. Batson and Shaw, however, define altruism and egoism so that they are properties of motives. The empathy-altruism hypothesis says that people have irreducibly other-directed motives. It is the existence of such motives, not their strength, that Batson and Shaw wish to establish. So the empathy-altruism hypothesis would be true if people were sometimes altruistic (in the sense just defined) in at least some of the choice situations they face. But note that this hypothesis would also be true even if people were moderate egoists in every situation they ever encountered. Moderate egoists have genuinely other-directed motives, but these are always weaker than the concern they have for selfinterest. The empathy-altruism hypothesis is consistent with people never being willing to sacrifice their own welfare for the sake of anyone else. Although I think this is an accurate characterization of the idea behind their hypothesis, Batson and Shaw sometimes give a rather different representation of what the issue is. For

How should the concept of evidence be understood? And how does the concept of evidence apply to the controversy about creationism as well as to work in evolutionary biology about natural selection and common ancestry? In this rich and wide-ranging book, Elliott Sober investigates general questions about probability and evidence and shows how the answers he develops to those questions apply to the specifics of evolutionary biology. Drawing on a set of fascinating examples, he analyzes whether claims about intelligent design are untestable; whether they are discredited by the fact that many adaptations are imperfect; how evidence bears on whether present species trace back to common ancestors; how hypotheses about natural selection can be tested, and many other issues. His book will interest all readers who want to understand philosophical questions about evidence and evolution, as they arise both in Darwin's work and in contemporary biological research.

When philosophers discuss the topic of explanation, they usually have in mind the following question: given the beliefs one has and some proposition that one wishes to explain, which subset of the beliefs constitutes an explanation of the target proposition? That is, the philosophical ‘problem of explanation’ typically has bracketed the issue of how one obtains the beliefs; they are taken as given. The problem of explanation has been the problem of understanding the relation ‘x explains y’. Since Hempel (1965) did so much to canonize this way of thinking about explanation, it deserves to be called ‘Hempel's problem’.

This chapter examines values and scientific evidence. It argues that one way to put the ideal of value freedom is believing that a proposition has good or bad ethical consequences is not evidence for its truth. The evidence relation is a three-place one between data, hypothesis, and background knowledge, thus allowing background knowledge to link fact and value. It is also argued that there is a qualified sense in which the value-free ideal is right: judgments about the moral consequences of a proposition cannot provide new information about its truth.

This article reviews two standard criticisms of creationism/intelligent design (ID): it is unfalsifiable, and it is refuted by the many imperfect adaptations found in nature. Problems with both criticisms are discussed. A conception of testability is described that avoids the defects in Karl Popper’s falsifiability criterion. Although ID comes in multiple forms, which call for different criticisms, it emerges that ID fails to constitute a serious alternative to evolutionary theory.