FORMAL AND FINAL CAUSES

The question of the status of functional explanation is inextricably bound up with the problem of teleology. Teleology is defined – somewhat infelicitously as we shall see – by the Oxford English Dictionary as “the doctrine or study of ends or final causes.” According to countless accounts of the rise of modern science, it is the rejection of such causes that characterizes science in the modern age. Thus, if functional explanations are closely associated with final causality, their scientific status would seem to be open to serious doubt.

Teleology, like so many polysyllabic philosophical terms of Greek origin and so intimately associated with Aristotle, was in fact the product of early modern German university philosophy, specifically of that inimitable conceptual taxonomist and philosophical pedant, Christian Wolff. It was introduced to denote a part of physics (or natural philosophy) that still lacked a name: namely the study of final causes as opposed to efficient causes, in particular the study of God's intentions in creating the world and the various things in it. This is precisely the sort of thing that Descartes and other heroes of the Scientific Revolution had banished from science and its philosophy.

A distinction is commonly made between a Platonic or “external” teleology and an Aristotelian or “internal” teleology. In the case of external teleology, the end achieved (or at least striven for) is the end desired by some intentional agent external to the object created or modified, and the value or good attained or conferred by achieving the goal is value for, at least from the perspective of, that agent.