Designators

Designators are linguistic expressions that designate or refer to entities in the world. In philosophy of language, the term groups expressions by their referential role rather than their truth-conditions alone. Common designators include proper names (Aristotle), definite descriptions (the inventor of bifocals), demonstratives (this book), and indexicals (now, here). A designator may pick out its referent through different mechanisms depending on the theory of reference.

Two influential accounts are the direct reference (causal) theory and descriptivism. The direct reference view, associated with Kripke and Putnam, holds that a name refers to a specific object through a historical chain of usage, independently of any descriptive content. The descriptivist view maintains that a designator conveys or relies on a bundle of descriptions that determine which object qualifies as referent, possibly aided by context.

Designators can be rigid, naming the same object in all possible worlds (proper names are often treated as rigid designators), or non-rigid, whose reference can vary with context. Key issues include how designators behave in opaque contexts, how they handle nonexistence or fictional entities, and how demonstratives depend on context. The study of designators also informs semantics of truth-conditions, presupposition, and the interaction of language with knowledge and belief.

In logic and computer science, the term is used more broadly for symbols that designate specific elements within a system, such as constant symbols, identifiers, or labels in databases and programming languages.