In this paper I defend an etiological theory of biological functions (according to which the proper function of a trait is the effect for which it was selected by natural selection) against three objections which have been influential. I argue, contrary to Millikan, that it is wrong to base our defense of the theory on a rejection of conceptual analysis, for conceptual analysis does have an important role in philosophy of science. I also argue that biology requires a normative notion (...) of a "proper function", and that a normative notion is not ahistorical. (shrink)

I defend the historical definition of "function" originally given in my Language, Thought and Other Biological Categories (1984a). The definition was not offered in the spirit of conceptual analysis but is more akin to a theoretical definition of "function". A major theme is that nonhistorical analyses of "function" fail to deal adequately with items that are not capable of performing their functions.

Biological functions are dispositions or effects a trait has which explain the recent maintenance of the trait under natural selection. This is the "modern history" approach to functions. The approach is historical because to ascribe a function is to make a claim about the past, but the relevant past is the recent past; modern history rather than ancient.

This paper argues that the medical conception of health as absence of disease is a value-free theoretical notion. Its main elements are biological function and statistical normality, in contrast to various other ideas prominent in the literature on health. Apart from universal environmental injuries, diseases are internal states that depress a functional ability below species-typical levels. Health as freedom from disease is then statistical normality of function, i.e., the ability to perform all typical physiological functions with at least typical efficiency. (...) This conception of health is as value-free as statements of biological function. The view that health is essentially value-laden, held by most writers on the topic, seems to have one of two sources: an assumption that health judgments must be practical judgments about the treatment of patients, or a commitment to "positive" health beyond the absence of disease. I suggest that the assumption is mistaken, the commitment possibly misdescribed. (shrink)

Millikan and Wilson argue, for different reasons, that the essential reference to the environment in adaptationist explanations of behavior makes (psychological) individualism inconsistent with evolutionary psychology. I show that their arguments are based on misinterpretations of the role of reference to the environment in such explanations. By exploring these misinterpretations, I develop an account of explanation in evolutionary psychology that is fully consistent with individualism. This does not, however, constitute a full-fledged defense of individualism, since evolutionary psychology is only one (...) explanatory paradigm among many in psychology. (shrink)

This paper reviews the debate on the notion of biological function and on functional explanation as this takes place in philosophy. It describes the different perspectives, issues, intuitions, theories and arguments that have emerged. The author shows that the debate has been too heavily influenced by the concerns of a naturalistic philosophy of mind and argues that in order to improve our understanding of biology the attention should be shifted from the study of intuitions to the study of the actual (...) practice of biological inquiry. (shrink)

I argue that there are at least four different ways in which the term ‘function’ is used in connection with the study of living organisms, namely: function as activity, function as biological role, function as biological advantage, and function as selected effect. Notion refers to what an item does by itself; refers to the contribution of an item or activity to a complex activity or capacity of an organism; refers to the value for the organism of an item having a (...) certain character rather than another; refers to the way in which a trait acquired and has maintained its current share in the population. The recognition of a separate notion of function as biological advantage solves the problem of the indeterminate reference situation that has been raised against a counterfactual analysis of function, and emphasizes the importance of counterfactual comparison in the explanatory practice of organismal biology. This reveals a neglected problem in the philosophy of biology, namely that of accounting for the insights provided by counterfactual comparison. (shrink)

I argue that there are at least four different ways in which the term ‘function’ is used in connection with the study of living organisms, namely: function as activity, function as biological role, function as biological advantage, and function as selected effect. Notion refers to what an item does by itself; refers to the contribution of an item or activity to a complex activity or capacity of an organism; refers to the value for the organism of an item having a (...) certain character rather than another; refers to the way in which a trait acquired and has maintained its current share in the population. The recognition of a separate notion of function as biological advantage solves the problem of the indeterminate reference situation that has been raised against a counterfactual analysis of function, and emphasizes the importance of counterfactual comparison in the explanatory practice of organismal biology. This reveals a neglected problem in the philosophy of biology, namely that of accounting for the insights provided by counterfactual comparison. (shrink)

There are two general approaches to characterising biological functions. One originates with Cummins. According to this approach, the function of a part of a system is just its causal contribution to some specified activity of the system. Call this the ‘C-function’ concept. The other approach ties the function of a trait to some aspect of its evolutionary significance. Call this the ‘E-function’ concept. According to the latter view, a trait's function is determined by the forces of natural selection. The C-function (...) and E-function concepts are clearly quite different, but there is an important relation between them which heretofore has gone unnoticed. The purpose of this paper is to outline that relation.This is not the first paper to discuss the relation of C-function and E-function. Previous attempts all follow either one of two strategies. The first proposes that the two concepts are ‘unified.’ The other proposes that they are radically distinct and apply to wholly different fields within biology. (shrink)

A biochemical pathway is a sequence of chemical reactions in a biological organism. Such pathways specify mechanisms that explain how cells carry out their major functions by means of molecules and reactions that produce regular changes. Many diseases can be explained by defects in pathways, and new treatments often involve finding drugs that correct those defects. This paper presents explanation schemas and treatment strategies that characterize how thinking about pathways contributes to biomedical discovery. It discusses the significance of pathways for (...) understanding the nature of diseases, explanations, and theories. (shrink)

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. (shrink)

Function and teleology can be naturalized either by reference to systems with a particular type of organization or by reference to a particular kind of history. As functions are generally ascribed to states or traits according to their current role and regardless of their origin, etiological accounts are inappropriate. Here, I offer a systems-theoretical interpretation as a new version of an organizational account of functionality, which is more comprehensive than traditional cybernetic views and provides explicit criteria for empirically testable function (...) ascriptions. I propose, that functional states, traits or items are those components of a complex system, which are under certain circumstances necessary for their self-re-production. I show, how this notion can be applied in intra- and trans-generational function ascriptions in biology, how it can deal with the problems of multifunctionality and functional equivalents, and how it relates to concepts like fitness and adaptation. Finally, I argue that most intentional explanations can be treated as functional explanations. (shrink)

"Modern History" versions of the etiological theory claim that in order for a trait X to have the proper function F, individuals with X must have been recently favored by natural selection for doing F (Godfrey-Smith 1994; Griffiths 1992, 1993). For many traits with prototypical proper functions, however, such recent selection may not have occurred: traits may have been maintained due to lack of variation or due to selection for other effects. I examine this flaw in Modern History accounts and (...) offer an alternative etiological theory, the Continuing Usefulness account, which appears to avoid such problems. (shrink)

Accounts of the concepts of function and dysfunction have not adequately explained what factors determine the line between low‐normal function and dysfunction. I call the challenge of doing so the line‐drawing problem. Previous approaches emphasize facts involving the action of natural selection (Wakefield 1992a, 1999a, 1999b) or the statistical distribution of levels of functioning in the current population (Boorse 1977, 1997). I point out limitations of these two approaches and present a solution to the line‐drawing problem that builds on the (...) second one. (shrink)

This paper will be about the relationship between mental disorder and physical disorder. I shall also be concerned with the connection between these notions and the notion of ‘illness’.

I shall begin with the "anti-psychiatry" view that the lack of a physical basis excludes many familiar mental disorders from the category of "illness". My response to this argument will be that anti-psychiatrists are probably right to hold that most mental disorders do not involve any physical disorder, but that they are wrong to conclude from this that these mental disorders are not illnesses.

In this paper I discuss recent debates concerning etiological theories of functions. I defend an etiological theory against two criticisms, namely the ability to account for malfunction, and the problem of structural doubles. I then consider the arguments provided by Bigelow and Pargetter (1987) for a more forward looking account of functions as propensities or dispositions. I argue that their approach fails to address the explanatory problematic for which etiological theories were developed.

Authors frequently refer to gene-based selection in biological evolution, the reaction of the immune system to antigens, and operant learning as exemplifying selection processes in the same sense of this term. However, as obvious as this claim may seem on the surface, setting out an account of “selection” that is general enough to incorporate all three of these processes without becoming so general as to be vacuous is far from easy. In this target article, we set out such a general (...) account of selection to see how well it accommodates these very different sorts of selection. The three fundamental elements of this account are replication, variation, and environmental interaction. For selection to occur, these three processes must be related in a very specific way. In particular, replication must alternate with environmental interaction so that any changes that occur in replication are passed on differentially because of environmental interaction. One of the main differences among the three sorts of selection that we investigate concerns the role of organisms. In traditional biological evolution, organisms play a central role with respect to environmental interaction. Although environmental interaction can occur at other levels of the organizational hierarchy, organisms are the primary focus of environmental interaction. In the functioning of the immune system, organisms function as containers. The interactions that result in selection of antibodies during a lifetime are between entities (antibodies and antigens) contained within the organism. Resulting changes in the immune system of one organism are not passed on to later organisms. Nor are changes in operant behavior resulting from behavioral selection passed on to later organisms. But operant behavior is not contained in the organism because most of the interactions that lead to differential replication include parts of the world outside the organism. Changes in the organism's nervous system are the effects of those interactions. The role of genes also varies in these three systems. Biological evolution is gene-based (i.e., genes are the primary replicators). Genes play very different roles in operant behavior and the immune system. However, in all three systems, iteration is central. All three selection processes are also incredibly wasteful and inefficient. They can generate complexity and novelty primarily because they are so wasteful and inefficient. Key Words: evolution; immunology; interaction; operant behavior; operant learning; replication; selection; variation. (shrink)

In this essay I defend functional explanations in sociobiology against the charge that they are exercises in speculative story-telling. I distinguish proximate and ultimate biological functions, and discuss their role in functional explanations. I characterize functional explanations as a kind of "consequence explanation", and argue that sociobiologists need to justify a "functional fact" in addition to a "consequence law". Two methods used to supply evidence for functional hypotheses, the technique of optimality analyses and the comparative method, are discussed and illustrated (...) with examples. I argue that adequate evidence for hypothesis about the function of a trait can be provided by the method of comparison, but not by optimality analyses. The comparative method contains an inductive phase that provides independent warrant for, and so serves to establish the high probability of, functional hypotheses. Independent warrant cannot be provided by optimality analyses alone: the model-building approach itself mandates the sacrifice of the truth of a hypothesis to its predictive power. I conclude that while the sociobiologist may wish to employ the optimality analysis as a heuristic strategy, reliable functional explanations are better sought through the use of the comparative method. (shrink)

The etiological approach to ‘proper functions’ in biology can be strengthened by relating it to Robert Cummins' general treatment of function ascription. The proper functions of a biological trait are the functions it is assigned in a Cummins-style functional explanation of the fitness of ancestors. These functions figure in selective explanations of the trait. It is also argued that some recent etiological theories include inaccurate accounts of selective explanation in biology. Finally, a generalization of the notion of selective explanation allows (...) an analysis of the proper functions of human artifacts. (shrink)

This paper examines the relationship between a family of concepts involving reliable correlation, and a family of concepts involving adaptation and biological function, as these concepts are used in the naturalistic semantic theory of Dretske's "Explaining Behavior." I argue that Dretske's attempt to marry correlation and function to produce representation fails, though aspects of his failure point the way forward to a better theory.

Selection type theories solve adaptation problems. Natural selection, clonal selection for antibody production, and selective theories of higher brain function are examples. An abstract characterization of typical selection processes is generated by analyzing and extending previous work on the nature of natural selection. Once constructed, this abstraction provides a useful tool for analyzing the nature of other selection theories and may be of use in new instances of theory construction. This suggests the potential fruitfulness of research to find other theory (...) types and construct their abstractions. (shrink)

Formulations of the essential commitment of the etiological theory of functions have varied significantly, with some individual authors' formulations even varying from one place to another. The logical geography of these various formulations is different from what is standardly assumed; for they are not stylistic variants of the same essential commitment, but stylistic variants of two non-equivalent versions of the etiological theory. I distinguish these “strong” and “weak” versions of the etiological theory (which differ with respect to the role of (...) selection in their definitions of function), draw out their respective implications, and argue that the weak version is to be preferred to the strong. (shrink)

Philosophers of evolutionary biology favor the so-called etiological concept of function according to which the function of a trait is its evolutionary purpose, defined as the effect for which that trait was favored by natural selection. We term this the selected effect (SE) analysis of function. An alternative account of function was introduced by Robert Cummins in a non-evolutionary and non-purposive context. Cummins''s account has received attention but little support from philosophers of biology. This paper will show that a similar (...) non-purposive concept of function, which we term causal role (CR) function, is crucial to certain research programs in evolutionary biology, and that philosophical criticisms of Cummins''s concept are ineffective in this scientific context. Specifically, we demonstrate that CR functions are a vital and ineliminable part of research in comparative and functional anatomy, and that biological categories used by anatomists are not defined by the application of SE functional analysis. Causal role functions are non-historically defined, but may themselves be used in an historical analysis. Furthermore, we show that a philosophical insistence on the primary of SE functions places practicing biologists in an untenable position, as such functions can rarely be demonstrated (in contrast to CR functions). Biologists who study the form and function of organismal design recognize that it is virtually impossible to identify the past action of selection on any particular structure retrospectively, a requirement for recognizing SE functions. (shrink)

Recently something close to a consensus about the best way to naturalize the notion of biological function appears to be emerging. Nonetheless, teleological notions in biology remain controversial. In this paper we provide a naturalistic analysis for the notion of natural design. Many authors assume that natural design should be assimilated directly to function. Others find the notion problematic because it suggests that evolution is a directed process. We argue that both of these views are mistaken. Our naturalistic account does (...) not simply equate design with function. We argue that the distinction between function and design is important for understanding the evolution of the physical and behavioral traits of organisms. (shrink)

With the advent of the Human Genome Project there have been many claims for the genetic origins of complex human behavior including insanity, criminality, and intelligence. But what does it really mean to call something 'genetic'? This is the fundamental question that Sahotra Sarkar's book addresses. The author analyses the nature of reductionism in classical and molecular genetics. He shows that there are two radically different kinds of reductionist explanation: genetic reduction (as found in classical genetics) and physical reduction (found (...) in molecular genetics). This important book clarifies the meaning of the term 'genetic', shows how molecular studies have affected genetics, and provides the philosophical background necessary to understand the debates over the Human Genome Project. It will be of particular interest to professionals and students in the philosophy of science, the history of science, and the social studies of science, medicine, and technology. (shrink)

INTRODUCTION The appeal to teleological principles of explanation within the body of natural science has had an unfortunate history. ...

The book presents a new way of understanding Darwinism and evolution by natural selection, combining work in biology, philosophy, and other fields.

Preface by Daniel C. Dennett Beginning with a general theory of function applied to body organs, behaviors, customs, and both inner and outer representations, ...

This text addresses the profound human questions of love and work. Beginning with a historical introduction, the author progresses through adaptive problems that humans face, and concludes by showing how evolutionary psychology encompasses all branches of psychology.

The philosophy of medicine and psychiatry has considered the defining of disease, illness, and disorder an important project for over three decades. Within this literature, accounts based on adaptive "functions" have been prominent, particularly in the DSM nosology. In response to this trend, Jerome Wakefield has presented a view of mental disorder as "harmful dysfunction." In this view, "harm" contributes the value-element to disorder concepts, while "dysfunction" implies a value-free foundation as long as the latter is grounded in evolutionary biology. (...) In a critical review of Wakefield's and others' functionalist arguments for disorder concepts, we make four major points. We recommend a shift away from the definition of value-free disorder concepts, instead emphasizing the analysis of the logical features and the value commitments in nosological categories. (shrink)