Friederike Moltmann Part Structures, Integrity, and the Mass-count Distinction

The notions of part and whole play an important role for ontology. They also play an important role in many areas of the semantics of natural language such as the mass-count distinction, certain semantic selectional requirements, and expressions whose lexical meaning is sensitive to the part structure of an object such as whole, together, and individual. In recent analyses both in philosophy and linguistic semantics, usually a particular notion of part structure has been used, that of extensional mereology. According to this notion, a part structure consists simply of a set of objects and an ordering among them, and objects are identical just in case they have the same parts. This paper argues that such a notion is insufficient for ontology and, especially, for the semantic analysis of the relevant constructions of natural language. What is needed for the notion of part structure, in addition to an ordering among parts, is the notion of integrated whole. Integrity plays a role for the identity of objects in that two objects that have the same parts may fail to be identical because one has integrity and the other does not, an example being a heap and the sand of which the heap consists. But integrity need not be essential for an object: an object may be only an accidental integrated whole, an example being the sand when taking the shape of a heap. Moreover, an entity may be only a conceived integrated whole, for example, the sand by being looked at as an ‘amount’ of sand. It is such a more general notion of integrity, comprising essential, accidental and conceived integrity, that, as I will argue, is important for the analysis of the relevant constructions of natural language. Given the possibility of accidental and conceived integrity, the same object may have integrity of different sorts in different ‘situations of reference’ or ‘contexts’ or be an integrated whole in one context and fail to be one in another context. Given that conditions of integrity are constitutive of part structures, this also means that an object may have different part structures in different contexts. The notion of integrated whole not only adds complexity to part structures; it also is responsible for why certain extensional mereological properties hold only conditionally for part structures in the new sense – in