Online research in philosophy

A meaningful distinction can be made between functions and mere effects in biological systems without resorting to teleological arguments: (i) biological systems must cope with a multitude of problems or they will cease to exist; (ii) the solutions to these problems invariably depend on circular causal chains (“feedback loops”); and (iii) biological functions are attributes of elements in biological systems that have an effect which, by contributing to the correcting behavior of a feedback control system, assists in solving a biological problem. The analysis is applied to several biological systems. The proposed solution is discussed primarily in its relation to two popular approaches to the concept of biological function, i.e., the “causal role accounts” and the “selected effect accounts”.

According to historical theories of biological function, a trait's function is determined by natural selection in the past. I argue that, in addition to historical functions, ahistorical functions ought to be recognized. I propose a theory of biological function which accommodates both. The function of a trait is the way it contributes to fitness and fitness can only be determined relative to a selective regime. Therefore, the function of a trait can only be specified relative to a selective regime. Apart from its desirable pluralism, only this view of relational function can support the function/accident and function/malfunction distinctions commonly thought to be part of the concept of function. Furthermore, only relational function correctly characterizes the explanatory consequences of function attributions in evolutionary biology.

"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.

Operational definitions of biological altruism in terms of actual fitness exchanges will not work because they include accidental acts as altruistic and exclude altruistic acts that have gone awry. I argue that the definition of biological altruism should contain an analogue of the role intention plays in psychological altruism. I consider two possibilities for this analogue, selected effect functions and the proximate causes and effects of behavior. I argue that the selected-effect function account will not work because it confuses the explanation of some altruistic behavior with the definition of all of it and the information needed to justify a selected effect account of function is too often inaccessible. Close attention to the proximate explanations of a behavior is all that is needed to determine if an act is biologically altruistic, returning biological altruism to descriptive ethology, where it belongs.

Both biological traits and artifacts have proper functions. But accounts of proper function are typically based on the biological case. So adapting these accounts to the artifact case requires finding cultural analogues of biological concepts. This can go wrong in two ways. The biological concepts may not pick out either biological or cultural proper functions correctly; or they may have no cultural analogues. I argue that things have gone wrong in the first way with regard to selection and in the second way with regard to fitness. Finally, I argue that the only way forward is to examine the phenomena of reproduction and use in material culture.

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.

Most philosophers adopt an etiological conception of functions, but not one that uniformly explains the functions attributed to material entities irrespective of whether they are natural or man-made. Here, I investigate the widespread idea that a combination of the two current etiological theories, SEL and INT, can offer a satisfactory account of the proper functions of both organisms and artifacts. (Roughly, SEL equates a function with a selected effect and INT with an intentional content). Making explicit what a realist theory of function supposes, I first show that SEL offers a realist theory of biological functions in which these are objective properties of a peculiar sort. I argue next that an artifact function demonstrates the same objective nature as a biological function when it is accounted for by SEL, but not when it is accounted for by INT. I explain why a dual theory of artifact functions admitting both INT and SEL functions is to be dismissed. I establish that neither INT nor SEL alone can account for all artifact functions. Drawing the conclusion that we need a new etiological theory of function, I show how one can overcome the apparent inevitability of INT for some artifact functions. Finally, I outline a new etiological theory of functions that applies equally to biological entities and to artifacts.

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.

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.

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.