ABSTRACT
To investigate the conceptual domain of necessity and possibility we constructed a language, Ln, described below, in which these modalities never fall within each others’ scopes. Thus, for a given proposition, p, the language can express “necessarily p” and “possibly p,” but not, for example, “possibly necessarily p,” or “necessarily necessarily p.” The reason for the restriction is that intuitions about the truth of the latter kind of construction are tenuous at best, so that their elimination does not seriously threaten the observational adequacy of the system. Since Lq does not allow quantifiers within each others’ scopes (see Section 3.1), and since only monadic predicates are included in that language, Lq and Ln turn out to be highly similar languages. The details follow.
