 There is, however, a certain ambiguity in the notion of a name of the piece of clay, inasmuch as the piece of clay may be any number of absolutely distinct objects. The notion of relative rigidity presupposes that a name for the piece of clay refers, with respect to some parameter \(p\), to whatever object counts as the piece of clay relative to that parameter. This may be sufficient in the case of the piece of clay, but in other cases it is not. With respect to a fixed parameter \(p\) there may be no unique object to serve as the referent of the name. For example, if any number of dog parts count, at a fixed time, as the same dog, then which of these objects serves as the referent of ‘Oscar’? We shall leave this question open for the time being but suggest that it may be worthwhile to view names such as ‘Oscar’ as instantial terms — terms introduced into discourse by means of existential instantiation. The name ‘Oscar’ might be taken as denoting a representative member of the equivalence class of distinct objects qualifying as the same dog as Oscar. It would follow, then, that most ordinary names are instantial terms. (An alternative is that of Geach 1980, who draws a distinction between a name of and a name for an object; see Noonan 1997 for discussion of Geach’s distinction.)