Abstract

It is a plain fact that biology makes use of terms and expressions commonly spoken of as teleological. Biologists frequently speak of the function of biological items. They may also say that traits are 'supposed to' perform some of their effects, claim that traits are 'for' specific effects, or that organisms have particular traits 'in order to' engage in specific interactions. There is general agreement that there must be something useful about this linguistic practice but it is controversial whether it is entirely appropriate, and if so why it is.Many theorists have defended the use of seemingly teleological terms by appeal to an etiological notion of function (Wright, 1973; Millikan, 1984, 2002; Neander, 1991; ..