 A third form of philosophy of biology occurs when philosophers appeal to biology to support positions on traditional philosophical topics, such as ethics or epistemology. The extensive literature on biological teleology is a case in point. After a brief flurry of interest in the wake of the “modern synthesis”, during which the term ‘teleonomy’ was introduced to denote the specifically evolutionary interpretation of teleological language (Pittendrigh 1958), the ideas of function and goal directedness came to be regarded as relatively unproblematic by evolutionary biologists. In the 1970s, however, philosophers started to look to biology to provide a solid, scientific basis for normative concepts, such as illness, disorder, or malfunction (Wimsatt 1972; Wright 1973; Boorse 1976). Eventually, the philosophical debate produced an analysis of teleological language fundamentally similar to the view associated with modern synthesis (Millikan 1984; Neander 1991; Godfrey-Smith 1994). According to the “selected effects” theory of function, the functions of a trait are those activities in virtue of which the trait was selected. The idea of proper function has become part of the conceptual toolkit of philosophy in general and of the philosophy of language and the philosophy of mind in particular (Dretske 1991, 1997; Millikan 1995, 2004, 2005; Papineau 1987, 1993; Neander 2017; Garson 2019).