In effect, Schaffner is arguing that the biomedical sciences employ a causal, rather than a teleological, concept of function. This is in the spirit of Cummins’s (1975) systemic analysis of function as the causal contribution a structure makes to the overall operation of the system that includes it. Cummins’s concept of function is not a historical or evolutionary concept. According to Cummins, a component of a system may have a function even it was not designed or selected for. Wakefield has ti