TELEOLOGICAL EXPLANATION IN BIOLOGY*†

EXPRESSIONs like ' function', ' purpose ',' role ' and ' in order to' occur in sentences in biology. For example: 'A function of liver is to secrete bile', ' The heart beats in order to circulate the blood', ' The role of the sodium chloride is to prevent the cells from taking up too much water '. Such sentences have been called ' functional analyses '. Functional analyses containing the expressions 'purpose', 'role ', ' in order to ' and similar teleological locutions can be rewritten using only 'function'. Thus 'A function of the heartbeat is to circulate the blood' says what the second example given above says. Functional analysis raises two closely related philosophical problems. The first centres on the teleological word 'function' e Does biology contain, irredeemably, sentences utilising teleological notions? Put another way : Can all functional analyses containing the locution 'function' be translated into sentences which contain neither 'func