Robinson's Regress Argument from Vagueness to Dualism

Howard Robinson's *From the Knowledge Argument to Mental Substance* contains two quite different arguments from the vagueness of composite objects to the conclusion that I am not a physical object at all. One of them, developed over the course of several chapters, takes the following form: All composite physical objects (and only composite physical objects are candidates to be a human being) are non-fundamental; non-fundamental things are inevitably vague in various ways; this vagueness shows that we must "make a conceptual interpretation of them", treating them as "artefacts of conceptualisation"; and this in turn precludes our identifying ourselves with any such things. Some interesting morals fall out of close consideration of Robinson's argument; but, in the end, materialists can reasonably resist it.