 This distinction between artifact kinds and functional kinds is relevant for the status of such kinds in comparison to other notions of kinds. Philosophy of science has emphasized that the concept of natural kind, such as exemplified by ‘water’ or ‘atom’, lies at the basis of science. On the other hand it is generally taken for granted that there are no regularities that all knives or airplanes or pistons answer to. This, however, is loosely based on considerations of multiple realizability that fully apply only to functional kinds, not to artifact kinds. Artifact kinds share an operational principle that gives them some commonality in physical features, and this commonality becomes stronger once a particular artifact kind is subdivided into narrower kinds. Since these kinds are specified in terms of physical and geometrical parameters, they are much closer to the natural kinds of science, in that they support law-like regularities; see for a defense of this position (Soavi 2009). A recent collection of essays that discuss the metaphysics of artifacts and artifact kinds is Franssen, Kroes, Reydon and Vermaas 2014.