Any study of the philosophical literature dealing with the cluster of topics generally identified as ‘functional description’, ‘functional analysis’, and ‘teleological explanation’ naturally raises the problem of confirming, disconfirming, or at least relating the alternative logical models proposed by philosophers to the actual usage of biologists. A close examination of current biological literature reveals that acceptance or rejection of what philosophers or sociologists might call a ‘functionalist’ perspective or approach is not significant for the division of biologists into schools or (...) factions. It is certainly not the case that a functionalist perspective distinguishes the wholistic or organismic faction from the molecular biologists. In fact, molecular biologists shift back and forth from ‘functional’ to simple causal perspectives with considerable indifference. This is particularly true of the literature based upon the so-called operon hypothesis developed by the Nobel laureates Jacob and Monod. (shrink)

Functional explanations are regarded as a special type of explanation by many biologists. Philosophers of science tend to agree that they are weak forms of the common modes of explanation, although the elucidation of the logical structure involved is difficult. The present paper shows that Hempel's reconstruction of functional explanations is inadequate on pragmatic grounds. Thus his conclusion that such explanations are necessarily weak is also objectionable. There is no reason for allotting functional explanations a special logical status.