Norms as Mental Objects - From Normative Beliefs to Normative Goals

The study of norms (Ns) is recent but growing concern in the AI field (cf. [MOS92]; [SHO92]) as well within other formal approaches to social action, such as Game Theory (where theories of Ns began to appear long before, cf.[LEW69]; [ULL77]). The normative is an essential dimension of social life. An explicit model of such dimension is crucial for any theory of social action. Notions such as "social commitment" (cf. [GAS91]; [COH90]; etc.) "joint intentions", "teamwork" [COH91], "negotiation" [DAV83], "social roles" [WER89] etc. will not escape a purely metaphorical use if their normative character is not accounted for. Indeed, one’s committing oneself before someone else causes the latter to be entitled, on the very basis of commitment, to expect, control, and exact the action one has committed oneself to. Social commitment is a customary, if not the most frequent, source of entitlements in everyday interaction: first of all, a promise creates an entitled expectation in the addressee, namely a belief that the promised course of action will be realized. As a consequence, the addressee feels entitled to exact the action expected, that is, to control its occurrence and react if it is not performed. In particular, the addressee is entitled to express a public protest and receive the consent and support of the community of witnesses before whom the action of commitment took place. Furthermore, there is no true negotiation without control for cheaters and norm of reciprocation (of. [GOU60]). When social agents negotiate an exchange of resources, they actually