 A proper name—the name of a primary substance—signifies a concrete individual (hoc aliquid), picking out its bearer as personally distinct from all else. Therefore, proper names are semantically singular referring expressions, closely allied to indexicals, demonstratives, and singular descriptions (or descriptive terms). Common names, by contrast, are semantically allied with expressions that have what Abelard calls “plural signification”. On the one hand, common names are like plural nouns; the common name ‘man’ is grammatically singular but operates like the plural term ‘men’—each refers to every man, although the plural term signifies individuals as part of a collection, whereas the common name distributively refers to each individual. On the other hand, common names are like terms such as ‘trio’ or ‘pair’ in that they pick out a determinate plurality of individuals, but only on an occasion of use, since their extension is variable.