This is a short overview of the biological functions debate in philosophy. While it was fairly comprehensive when it was written, my short book ​A Critical Overview of Biological Functions has largely supplanted it as a definitive and up-to-date overview of the debate, both because the book takes into account new developments since then, and because the length of the book allowed me to go into substantially more detail about existing views.

Explores the development of the ideas of evolutionary biology, particularly as affected by the increasing understanding of genetics and of the chemical basis of inheritance.

Comprehensive evaluation and study of man's theories and knowledge of genetical characteristics and the evolutionary processes.

A common misunderstanding of the selected effects theory of function is that natural selection operating over an evolutionary time scale is the only functionbestowing process in the natural world. This construal of the selected effects theory conflicts with the existence and ubiquity of neurobiological functions that are evolutionary novel, such as structures underlying reading ability. This conflict has suggested to some that, while the selected effects theory may be relevant to some areas of evolutionary biology, its relevance to neuroscience is (...) marginal. This line of reasoning, however, neglects the fact that synapses, entire neurons, and potentially groups of neurons can undergo a type of selection analogous to natural selection operating over an evolutionary time scale. In the following, I argue that neural selection should be construed, by the selected effect theorist, as a distinct type of function-bestowing process in addition to natural selection. After explicating a generalized selected effects theory of function and distinguishing it from similar attempts to extend the selected effects theory, I do four things. First, I show how it allows one to identify neural selection as a distinct function-bestowing process, in contrast to other forms of neural structure formation such as neural construction. Second, I defend the view from one major criticism, and in so doing I clarify the content of the view. Third, I examine drug addiction to show the potential relevance of neural selection to neuroscientific and psychological research. Finally, I endorse a modest pluralism of function concepts within biology. (shrink)

Despite the voluminous literature on biological functions produced over the last 40 years, few philosophers have studied the concept of function as it is used in neuroscience. Recently, Craver (forthcoming; also see Craver 2001) defended the causal role theory against the selected effects theory as the most appropriate theory of function for neuroscience. The following argues that though neuroscientists do study causal role functions, the scope of that theory is not as universal as claimed. Despite the strong prima facie superiority (...) of the causal role theory, the selected effects theory (when properly developed) can handle many cases from neuroscience with equal facility. It argues this by presenting a new theory of function that generalizes the notion of a ‘selection process’ to include processes such as neural selection, antibody selection, and some forms of learning—that is, to include structures that have been differentially retained as well as those that have been differentially reproduced. This view, called the generalized selected effects theory of function, will be defended from criticism and distinguished from similar views in the literature. (shrink)

The effects of mental disorder are apparent and pervasive, in suffering, loss of freedom and life opportunities, negative impacts on education, work satisfaction and productivity, complications in law, institutions of healthcare, and more. With a new edition of the 'bible' of psychiatric diagnosis - the DSM - under developmental, it is timely to take a step back and re-evalutate exactly how we diagnose and define mental disorder. This new book by Derek Bolton tackles the problems involved in the definition and (...) boundaries of mental disorder. It addresses two main questions regarding mental illness. Firstly, what is the basis of the standards or norms by which we judge that a person has a mental disorder - that the person's mind is not working as it should, that their mental functioning is abnormal? Controversies about these questions have been dominated by the contrast between norms that are medical, scientific or natural, on the one hand, and social norms on the other. The norms that define mental disorder seem to belong to psychiatry, to be medical and scientific, but are they really social norms, hijacked and disguised by the medical profession? Secondly, what is the validity of the distinction between mental disorder and order, between abnormal and normal mental functioning? To what extent, notwithstanding appearances, does mental disorder involve meaningful reactions and problem-solving? These responses may be to normal problems of living, or to not so normal problems - to severe psycho-social challenges. Is there after all order in mental disorder? With the closing of asylums and the appearance of care in the community, mental disorder is now in our midst. While attempts have been made to define clearly a concept of mental disorder that is truly medical as opposed to social, there is increasing evidence that such a distinction is unviable - there is no clear line between what is normal in the population and what is abnormal. 'What is Mental Disorder?' reviews these various crucial developments and their profound impact for the concept and its boundaries in a provocative and timely book. (shrink)

Kenneth F. Schaffner compares the practice of biological and medical research and shows how traditional topics in philosophy of science—such as the nature of theories and of explanation—can illuminate the life sciences. While Schaffner pays some attention to the conceptual questions of evolutionary biology, his chief focus is on the examples that immunology, human genetics, neuroscience, and internal medicine provide for examinations of the way scientists develop, examine, test, and apply theories. Although traditional philosophy of science has regarded scientific discovery—the (...) questions of creativity in science—as a subject for psychological rather than philosophical study, Schaffner argues that recent work in cognitive science and artificial intelligence enables researchers to rationally analyze the nature of discovery. As a philosopher of science who holds an M.D., he has examined biomedical work from the inside and uses detailed examples from the entire range of the life sciences to support the semantic approach to scientific theories, addressing whether there are "laws" in the life sciences as there are in the physical sciences. Schaffner's novel use of philosophical tools to deal with scientific research in all of its complexity provides a distinctive angle on basic questions of scientific evaluation and explanation. (shrink)

Debate about adaptationism in biology continues, in part because within “the” problem of assessing adaptationism, three distinct problems are mixed together. The three problems concern the assessment of three distinct adaptationist positions, each of which asserts the central importance of adaptation and natural selection to the study of evolution, but conceives this importance in a different way. As there are three kinds of adaptationism, there are three distinct "anti-adaptationist" positions as well. Or putting it more formally, there are three different (...) dimensions here, and strongly adaptationist views, strongly anti-adaptationist views, and moderate views are possible for each dimension. (shrink)

How should we define ‘health’ and ‘disease’? There are three main positions in the literature. Naturalists desire value-free definitions based on scientific theories. Normativists believe that our uses of ‘health’ and ‘disease’ reflect value judgments. Hybrid theorists offer definitions containing both normativist and naturalist elements. This paper discusses the problems with these views and offers an alternative approach to the debate over ‘health’ and ‘disease’. Instead of trying to find the correct definitions of ‘health’ and ‘disease’ we should explicitly talk (...) about the considerations that are central in medical discussions, namely state descriptions and normative claims . This distinction avoids the problems facing the major approaches to defining ‘health’ and ‘disease’, and it more clearly captures what matters in medical discussions. (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)

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)

This essay replies to critics since 1995 of my “biostatistical theory” of health. According to the BST, a pathological condition is a state of statistically species-subnormal biological part-functional ability, relative to sex and age. Theoretical health, the total absence of pathological conditions, is then a value-free scientific notion. Recent critics offer a mixture of old and new objections to this analysis. Some new ones relate to choice of reference class, situation-specificity of function, common diseases and healthy populations, improvements in population (...) health, the practice of pathologists, “Cambridge changes” in health status, and comparative vs. absolute health concepts. I make no changes in doctrine, except to consider treating “normal aging” as pathological by taking young adults as the standard for all adults. (shrink)

I adopt a cladistic view of species, and explore the possibility that there exists an equally valuable cladistic view of organismic traits. This suggestion seems to run counter to the stress on functional views of biological traits in recent work in philosophy and psychology. I show how the tension between these two views can be defused with a multilevel view of biological explanation. Despite the attractions of this compromise, I conclude that we must reject it, and adopt an essentially cladistic (...) conception of biological traits. (shrink)

Many objects in the world have functions. Typewriters are for typing. Can-openers are for opening cans. Lawnmowers are for cutting grass. That is what these things are for. Every day around the world people attribute functions to objects. Some of the objects with functions are organs or parts of living organisms. Hearts are for pumping blood. Eyes are for seeing. Countless works in biology explain the “Form, Function, and Evolution of... ” everything from bee dances to elephant tusks to pandas’ (...) ‘thumbs’. Many scientific explanations, in areas as diverse as psychology, sociology, economics, medical research, and neuroscience, rest on appeals to the function and/or malfunction of things or systems. They talk of how humans and other organisms or their parts work, what their functions are, why they are present, and how different situations will affect them and how they will react. Philosophers, going back to Aristotle, used to make generous use of functions in describing objects, organisms, their interactions, and even as the basis of ethics and metaphysics. And yet, since the Enlightenment, talk of the function of natural objects, teleological function, began to be viewed with suspicion, as the mechanical model of the world replaced the old Aristotelian model. From a religious standpoint, it used to be easy to see how objects in the natural world could have natural functions, for God was said to instill functions by design throughout Creation. But philosophers became increasingly reluctant to invoke God to solve every difficult philosophical problem, and became unwilling to indulge in such religious explanations of teleology. (shrink)

The most recent resurgence of philosophical attention to the so-called ‘functional talk' in the sciences can be summarized in terms of the following questions: (Q1) What kind of restrictions, and in particular, what kind of evolutionary restrictions as well as to what extent, is involved in functional ascriptions? (Q2) How can we account for the explanatory import of function-ascribing statements? This paper addresses these questions through a modified version of Cummins' functional analysis. The modification in question is concerned with phylogenetical (...) restrictions on causal role functions, and it stems from an analysis of some primary areas in molecular biology. I examine how evolutionary consideration affects the so-called ‘function-analytical explanatory strategy' (Cummins [1975] 1998, 2002). Finally, I argue that the neo-functional analysis here proposed accounts for a certain convergence between the main rival theories of biological function. ‡I wish to thank David Davies, Eva Jablonka, Thomas Reydon, and Marcel Weber for their helpful comments. †To contact the author, please write to: Department of Philosophy, University of Rijeka, Omladinska 14, 51000 Rijeka, Croatia; e-mail: [email protected]. (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)

The crucial problem in the philosophy of psychiatry is to determine under which conditions certain behaviors, mental states, and personality traits should be regarded as symptoms of mental illnesses. Participants in the debate can be placed on a continuum of positions. On the one side of the continuum, there are naturalists who maintain that the concept of mental illness can be explained by relying on the conceptual apparatus of the natural sciences, such as biology and neuroscience. On the other side (...) of the continuum, there are normativists who maintain that the appropriate characterization of the concept of mental illness cannot avoid reference to epistemic, moral and other social values. Although, this article is primarily an introduction to the debate, we stress the importance of the normativist positions. (shrink)