If this argument is sound, then physical theory will never provide us with a complete and adequate account of the nature of the material world. The job of physics is to provide us with mathematical models that accurately predict the behaviour of matter. This is incredibly useful information; rich understanding of the causal structure of matter has enabled us to manipulate the natural world in all sorts of extraordinary ways, allowing us to build lasers and hairdryers, and to put men on the moon. Indeed we can explain the extraordinary success of physics in terms of the fact that from Galileo onwards it focused on this more limited project of capturing matter’s causal structure, rather than speculating about the underlying nature of the stuff that has that structure.