 Or we may supplement the language of propositional logic with a propositional quantifier, \(\forall\), which is allowed to bind propositional letters such as \(p\), \(q\), \(r\), …. This is, for example, the course of action taken by Prior (1971), who outlines a system of propositional quantification. Prior insisted that propositional quantification should not be confused with either objectual quantification over propositions or substitutional quantification over sentences. Rather, propositional quantification is a species of non-nominal quantification, since it is quantification into sentence position.