The Oxford Companion to Philosophy (2 ed.)
From the Greek word for goal, task, completion, or perfection. Teleological explanations attempt to account for things and features by appeal to their contribution to optimal states, or the normal functioning, or the attainment of goals, of wholes or systems they belong to. Socrates' story (in Plato's Phaedo) of how he wanted to understand things in terms of what is best is an early discussion of teleology. Another is Aristotle's discussion of ‘final cause’ explanations in terms of that for the sake of which something is, acts, or is acted upon. Such explanations are parodied in Voltaire's Candide.
There are many cases in which an item's contribution to a desirable result does not explain its occurrence. For example, what spring rain does for crops does not explain why it rains in the spring. But suppose we discovered that some object's features were designed and maintained by an intelligent creator to enable it to accomplish some purpose. Then an understanding of a feature's contribution to that purpose could help us explain its presence without mistakenly assuming that everything is as it is because of the effects it causes. There are many things (e.g. well-designed clocks in good working order) known to have been produced by intelligent manufacturers for well-understood purposes, whose features can, therefore, be explained in this way. But if all teleological explanation presupposes intelligent design, only creationists could accept teleological explanations of natural things, and only conspiracy theorists could accept teleological explanations of economic and social phenomena.
Teleological explanations which do not presuppose that what is to be explained is the work of an intelligent agent are to be found in biology, economics, and elsewhere. Their justification typically involves two components: an analysis of the function of the item to be explained and an aetiological account.
Functional analysis seeks to determine what contribution the item to be explained makes to some main activity, to the proper functioning, or to the well-being or preservation, of the organism, object, or system it belongs to. For example, given what is known about the contribution of normal blood circulation to the main activities and the well-being of animals with hearts, the structure and behaviour of the heart lead physiologists to identify its function with its contribution to circulation. Given the function of part of an organism, the function of a subpart (e.g. some nerve-ending in the heart) can be identified with its contribution—if any—to the function of the part (e.g. stimulating heart contractions). Important empirical problems in biology and the social sciences and equally important conceptual problems in the philosophy of science arise from questions about the evaluation of ascriptions of purposes and functions.
Functional analysis cannot explain a feature's presence without an aetiological account which explains how the feature came to be where we find it. In natural-selection explanations, aetiological accounts typically appeal to (a) genetic transmission mechanisms by which features are passed from one generation to the next and (b) selection mechanisms (e.g. environmental pressures) because of which organisms with the feature to be explained have a better chance to reproduce than organisms which lack it. The justification of teleological explanations in sociobiology, anthropology, economics, and elsewhere typically assumes the possibility of finding accounts of transmission and selection mechanisms roughly analogous to (a) and (b).
- A. Ariew, R. Cummins, and M. Perlman (eds.), Functions (Oxford, 2002).
- Morton O. Beckner, Biological Ways of Thought (Berkeley, Calif., 1968), chs. 6–8.
- Larry Wright, ‘Functions’, Christopher Bourse, ‘Wright on Functions’ Robert Cummins, ‘Functional Analysis’ (along with further references to standard literature), in Elliott Sober (ed.), Conceptual Issues in Evolutionary Biology (Cambridge, Mass., 1984).