A Taxonomy of Functions

Abstract

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’ (or ‘Cummins function’) concept. The other approach ties the function of a trait to some aspect of its evolutionary significance. Call this the ‘E-function’ (or ‘evolutionary 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.

The Function Debate in Philosophy

“…However, in the course of the 1990s the awareness grew that there are several senses of function involved in the study of biology. As I indicated in Section 2.4, nowadays many philosophers acknowledge two main notions of biological function: a teleological, evolutionary notion that serves to explain trait presence and a (non-evolutionary) physiological one that serves to explain complex activities or capacities (see for example Millikan, 1989aMillikan, , 1993aMillikan, , 2002Godfrey-Smith, 1993;Kitcher, 1993;Griffiths, 1993;Amundson andLauder, 1994, Walsh andAriew, 1996;Walsh, 1996). Whereas Millikan and Godfrey-Smith suggest that these two notions are to be analyzed in different ways (along the lines of the selected effects and the systemic approach, respectively).…”

“…Boorse (2002: 64) seems to agree. Walsh and Ariew (1996), on the other hand, see the life chances theory of Bigelow and Pargetter (1987) as an evolutionary theory of function. This is a mistake precisely because of the counterfactual character of the comparison by which functions are to be established according to Bigelow and Pargetter.…”

Teleosemantics: Etiological Foundations

“…It just causes the survival and reproduction. Moreover, on Millikan’s own definition of function, the requirement of a type’s reproduction due to its having certain effects on certain occasions when it played a pivotal role is a requirement of causal efficacy, not of selection (Buller 1998: 511; Walsh and Ariew 1996/1999: 508).…”

Functions and Health at the Interface of Biology and Technology

“…My taxonomy roughly coincides with those of Godfrey‐Smith (; ), Lewens (), Neander (), Schlosser (1993; who calls causal role approaches ‘organizational approaches’), Schwartz (), and Roszkowski (). But see Walsh & Ariew () or Perlman () for alternative and more detailed classifications. See Nanay () for a quite different ‘modal’ account of function that I do not discuss here.…”