We examine to what extent an adequate ontology of technical artefacts can be based on
existing general accounts of the relation between higher-order objects and their material
basis. We consider two of these accounts: supervenience and constitution. We take as our
starting point the thesis that artefacts have a 'dual nature', that is, that they are both material
bodies and functional objects. We present two criteria for an adequate ontology of artefacts,'
Underdetermination'(UD) and 'Realizability Constraints'(RC), which address aspects of the …