Elliott Sober

In my paper “Intelligent Design Theory and the Supernatural—the ‘God or Extra-Terrestrial’ Reply,” I argued that Intelligent Design (ID) Theory, when coupled with independently plausible further assumptions, leads to the conclusion that a supernatural intelligent designer exists. ID theory is therefore not neutral on the question of whether there are supernatural agents. In this respect, it differs from the Darwinian theory of evolution. John Beaudoin replies to my paper in his “Sober on Intelligent Design Theory and the Intelligent Designer,” arguing that my paper faces two challenges. In the present paper, I try to address Beaudoin’s challenges.

The concept of fitness began its career in biology long before evolutionary theory was mathematized. Fitness was used to describe an organism’s vigor, or the degree to which organisms “fit” into their environments. An organism’s success in avoiding predators and in building a nest obviously contribute to its fitness and to the fitness of its offspring, but the peacock’s gaudy tail seemed to be in an entirely different line of work. Fitness, as a term in ordinary language (as in “physical fitness”) and in its original biological meaning, applied to the survival of an organism and its offspring, not to sheer reproductive output (Paul ////; Cronin 1991). Darwin’s separation of natural from sexual selection may sound odd from a modern perspective, but it made sense from this earlier point of view.

Alexander Rosenberg begins his recent article on the concept of fitness with the remark that "debates about the cognitive status of the Darwinian theory of natural selection should have ended long ago." I agree that this obsession needs to be overcome. But Rosenberg repeats some of the old mis- takes and invents epicycles on others. In this comment I will not be able to circumscribe fully the range of topics that an adequate treatment of this cluster of problems demands. A few critical re marks will indicate what I find wanting in Rosenberg's treatment

The Nature of Selection is a straightforward, self-contained introduction to philosophical and biological problems in evolutionary theory. It presents a powerful analysis of the evolutionary concepts of natural selection, fitness, and adaptation and clarifies controversial issues concerning altruism, group selection, and the idea that organisms are survival machines built for the good of the genes that inhabit them. "Sober's is the answering philosophical voice, the voice of a first-rate philosopher and a knowledgeable student of contemporary evolutionary theory. His book merits broad attention among both communities. It should also inspire others to continue the conversation."-Philip Kitcher, Nature "Elliott Sober has made extraordinarily important contributions to our understanding of biological problems in evolutionary biology and causality. The Nature of Selection is a major contribution to understanding epistemological problems in evolutionary theory. I predict that it will have a long lasting place in the literature."-Richard C. Lewontin

The naïve see causal connections everywhere. Consider the fact that Evelyn Marie Adams won the New Jersey lottery twice. The naïve find it irresistible to think that this cannot be a coincidence. Maybe the lottery was rigged or perhaps some uncanny higher power placed its hand upon her brow. Sophisticates respond with an indulgent smile and ask the naïve to view Adams’ double win within a larger perspective. Given all the lotteries there have been, it isn’t at all surprising that someone would win one of them twice. No need to invent conspiracy theories or invoke the paranormal – the double win was a mere coincidence.

Quine has developed two reasons for thinking that our ontology should not include the ontological category of properties. His first point is that the criterion for individuating properties is unclear, and the second is that postulating the existence of properties would not explain anything. In what follows I critically examine these two themes, which I will call the clarity argument and the parsimony argument. Although I will suggest that these two arguments are defective, I also will try to show that certain related arguments on behalf of the existence of properties are likewise flawed. This will set the stage for the discussion in the fourth section of the perspective provided by evolutionary theory on the question of the ontological status of properties. It will emerge that evolutionary theory provides reason for thinking that properties exist, and, additionally, gives an interesting point of view on the epistemological and metaphysical issues that Quine has addressed.

Nancy Cartwright (1983, 1999) argues that (1) the fundamental laws of physics are true when and only when appropriate ceteris paribus modifiers are attached and that (2) ceteris paribus modifiers describe conditions that are almost never satisfied. She concludes that when the fundamental laws of physics are true, they don't apply in the real world, but only in highly idealized counterfactual situations. In this paper, we argue that (1) and (2) together with an assumption about contraposition entail the opposite conclusion — that the fundamental laws of physics do apply in the real world. Cartwright extracts from her thesis about the inapplicability of fundamental laws the conclusion that they cannot figure in covering-law explanations. We construct a different argument for a related conclusion — that forward-directed idealized dynamical laws cannot provide covering-law explanations that are causal. This argument is neutral on whether the assumption about contraposition is true. We then discuss Cartwright's simulacrum account of explanation, which seeks to describe how idealized laws can be explanatory.

In their book What Darwin Got Wrong, Jerry Fodor and Massimo Piattelli-Palmarini construct an a priori philosophical argument and an empirical biological argument. The biological argument aims to show that natural selection is much less important in the evolutionary process than many biologists maintain. The a priori argument begins with the claim that there cannot be selection for one but not the other of two traits that are perfectly correlated in a population; it concludes that there cannot be an evolutionary theory of adaptation. This article focuses mainly on the a priori argument.

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.

The positivists suggest that some truths may be immune from empirical refutation and yet lacking in rational justification. Quine holds that every proposition is in principle empirically refutable so there are no a priori truths. I’ll provide a working characterization of the idea of “rational revisability” and argue it’s impossible for us to take a chain of rational revision and end up revising everything which we now believe. Quine's position on revisability is also in tension with certain theses about epistemic holism. Finally, I discuss a more general context in which rational argument is viewed as one mechanism among many for reliably modifying beliefs. This more biological perspective allows us to formulate Quine's claims about revisability in a new way and to raise some interesting questions about the potential impact of natural selection on our cognitive capacities.

In what follows I will discuss an example of the Duhem-Quine problem in which Pr(H A), Pr(A H), and Pr(OI +H& ?A) (where H is the hypothesis, A the auxiliary assumptions, and O the observational prediction) can be construed objectively; however, only some of those quantities are relevant to the analysis that I provide. The example involves medical diagnosis. The goal is to test the hypothesis that someone has tuberculosis; the auxiliary assumptions describe the er- ror characteristics of the test procedure. Although it can make sense to talk about the objective probability that someone (randomly drawn from a given population) has tuberculosis and it also can make sense to talk about the objective probability that a test procedure has a certain set of error characteristics, neither of these quantities will enter into the analysis. The analysis proceeds entirely via likelihoods, what one needs to consider is just the probability of the observations conditional on four conjunctions of the form (?H & +A).' It is a special feature of the example that all four of these conjunctions are simple statistical hypotheses in the technical sense that each unambigu-ously confers a probability on the observations.'o After describing how the likelihood concept applies to the example concerning medical diagnosis, I will show how similar patterns can arise in the context of a second inferential framework-that of H. Akaike's criterion of model selection;" this time the example will involve phylogenetic inference.

Solipsism poses a familiar epistemological problem. Each of us has beliefs about a world that allegedly exists outside our own minds. The problem is to justify these nonsolipsistic convictions. One standard approach is to argue that the existence of things outside our own sensations may reasonably be inferred from regularities that obtain within our sensations. Certain experiences, which I will call tiger sounds and tiger visual images, exhibit a striking correlation. We can explain the existence of this correlation by postulating an entity that is a cause of both. If there were tigers, it would be no surprise that certain sights and certain sounds tend to co-occur. Our rejection of solipsism can thus be justified by appeal to an abductive argument; we advance an inference to the best explanation conforming to the pattern that Reichenbach called the principle of the common cause.

Is all explanations causal explanation? Puzzles about barometer readings "explain" storms and shadow lengths "explaining" flagpole heights make it attractive to think so. Wesley Salmon (1984) has endorsed this causal thesis. One way to test this thesis is to assess the explanatory import of pseudo-processes. I do so by discussing the concept of heritability, which measures a pseudo-process, and one role it played in the theory of natural selection: explaining response to selection. This will show, not just that heritability has heuristic or predictive utility, but that it can be explanatory. Possible responses to this case are also discussed.

The logical empiricists said some good things about epistemology and scientific method. However, they associated those epistemological ideas with some rather less good ideas about philosophy of language. There is something epistemologically suspect about statements that cannot be tested. But to say that those statements are meaningless is to go too far. And there is something impossible about trying to figure out which of two empirically equivalent theories is true. But to say that those theories are synonymous is also to go too far. My goal in this paper is not to resuscitate all these positivist ideas, but to revisit just one of them. Instrumentalism is the idea that theories are instruments for making predictions. Of course, no one would disagree that this is one of the things we use theories to do. In just the same way, no one could disagree with the emotivist claim that one of the things we do with ethical terms like "good" and "right" is to express our feelings of approval and disapproval. Instrumentalism and emotivism become contentious, and therefore interesting, when these claims are supplemented.

In this paper I want to clarify what biologists are talking about when they talk about the evolution of altruism. I’ll begin by saying something about the common sense concept. This familiar idea I’ll call ‘vernacular altruism.’ One point of doing this is to make it devastatingly obvious that the common sense concept is very different from the concept as it’s used in evolutionary theory. After that preliminary, I’ll describe some features of the evolutionary concept. Then I’ll conclude by briefly considering what explanatory relation might obtain between vernacular altruism and evolutionary altruism. Although the points I’ll make are rather elementary ones, their interest is not restricted to those who have never heard of the evolutionary problem. The reason for this is that there is some amount of confusion about evolutionary altruism among evolutionary biologists themselves.