On the Representation of Normative Sentences in FOL

Rules, regulations and policy statements quite frequently contain nested sequences of normative modalities as in, for example:

The database manager is obliged to permit the deputy-manager to authorise access for senior departmental staff.

Parking on highways ought to be forbidden. [24]

Accordingly, a knowledge-representation language for such sentences must be able to accommodate nesting of this kind. However, if—as some have proposed—normative modalities such as

obligatory, permitted,

and

authorised

are to be interpreted as first-order predicates of named actions, then nesting appears to present a problem, since the scope formula of

obligatory

in “obligatory that it is permitted that

a

” (where

a

names an action) is not a name but a sentence.

The ‘disquotation’ theory presented in Kimbrough (“A Note on Interpretations for Federated Languages and the Use of Disquotation”, and elsewhere) may provide a candidate solution to this FOL problem. In this paper we rehearse parts of that theory and evaluate its efficacy for dealing with the indicated normative nesting problem.