Abstract

'Modern History' views claim that in order for a trait X to have the proper function F, X must have been recently favored by natural selection for doing F (Griffiths 1992, 1993; Godfrey-Smith 1994). For many traits with prototypical proper functions, however, such recent selection may not have occurred, since traits may have been maintained owing to lack of variation or selection for other effects. I explore this flaw in Modern History accounts and offer an alternative etiological theory, which I call the 'Continuing Usefulness' account. According to my view, a trait has the proper function F if and only if, first, the trait was favored by selection for doing F at some point (perhaps far in the past), and, secondly, the trait has recently contributed to survival and reproduction by doing F. This separates the requirement involving natural selection from the one involving the recent past, two issues that the Modern History account conflates. The clear separation allows a detailed analysis of the causal judgments and form of adaptationism that ground the etiological approach to function.