The Logical Structure of Functional Explanations in Biology

The philosophical literature is heavy with discussions of the logical structure of various proposed schema of functional explanation (most of which are modifications of Hempel's schema [7]) but it is very light on detailed analysis of the way in which these schema actually work or the way in which they apply to the instances in which functional explanations are used by scientists. These papers use statements by scientists ascribing particular functions to particular traits, along with intuitions about the way in which ‘function’ is used in ordinary language, to ascertain the referents of the term and thus to determine the class of uses against which any schema should be tested; but such examples only show whether the schema under discussion refer to the same things as those the scientists’ refer to; they do not show whether the logical structure of the schema really captures the logical structure underlying the scientists’ use.