A formal framework for agency and autonomy

With the recent rapid growth of interest in Multi-Agent Systems, both in articial intelligence and soft-ware engineering, has come an associated diculty concerning basic terms and concepts. In particular, the terms agency and autonomy are used with increas-ing frequency to denote dierent notions with dier-ent connotations. In this paper we lay the foundations for a principled theory of agency and autonomy, and specify the relationship between them. Using the Z speci cation language, we describe a three-tiered hi-erarchy comprising objects, agents and autonomous agents where agents are viewed as objects with goals, and autonomous agents are agents with motivations