  Contextualist theories for an expression should be distinguished from invariantist theories that hypothesize hidden indexicals. On views of the latter sort, the expression itself is context-insensitive, but its occurrences are (often) accompanied by occurrences of an unpronounced expression that is context-sensitive. These context-sensitive expressions are sometimes said to be, or to resemble, indexicals, pronouns, or variables. For illustration, consider the gradable adjective ‘rich’. A strict contextualist theory would claim that this adjective is a unary predicate whose content in any context is a unary property. In some contexts, the content of ‘rich’ is (roughly) the property of being rich for a philosopher, while in others its content is the property of being rich for the CEO of a large company. By contrast, an invariantist theory with hidden indexicals for ‘rich’ would claim that the content of ‘rich’ does not vary from context to context: its content, in every context, is the same binary relation, roughly rich for, that can hold between a person and (roughly) a property. Sometimes the predicate ‘rich’ appears in sentences in which it has two (linguistic) arguments, as in ‘George is rich for a philosopher’. But in sentences in which there is no pronounced second argument, as in ‘George is rich’, the predicate ‘rich’ is accompanied by an unpronounced occurrence of a context-sensitive expression that resembles a pronoun. In some contexts, the content of the hidden indexical is the property of being a philosopher and in others it is the property of being a CEO of a large company. See Partee (1989), Condoravdi and Gawron (1996), Stanley and Szabo 2000.