Abstract

Starting from the idea that functions are formally similar to actions in that they are described and explained in a similar way, so that both admit of an accordion effect, I turn to Anscombe’s insight that the point of practical reasoning is to render explicit the relation between the different descriptions of an action generated by the accordion effect. The upshot is, roughly, that an item has a function if what it does can be accounted for by functional reasoning. Put differently, a part of a system has a function if what it does is a functional part of what the system does.