Both formal analysis in the sense of proving theorems about the properties of agent and mechanism design and the use of formalisms as representation languages have been central elements in the foundation of multi agent systems research. The choice and frequently the development of formalisms for the specification and description of multi agent systems has been guided by intuition regarding the importance and nature of such concepts as belief and intention. An alternative to this foundational approach is a representational approach developed by modellers of observed social systems who design agents and mechanisms to capture observed behaviour and modes of social interaction. While the foundational approach has had an important influence on the research agenda of agent based social simulation, the representational techniques of agent based social simulation modellers have had no discernable influence on formalistic approaches to software engineering for multi agent systems. The purpose of this paper is to define a means of making available the lessons of real social systems to adopting formal approaches to MAS design. The means employed turns on the development of a canonical model capturing features of an observed social system in a way that relates explicitly to concepts such as belief, desire, intention, commitment, norms, obligation and responsibility. As a result, it is possible to define these concepts with minimal ambiguity either as an alternative to the use of formalisms as representation languages or as a bridge to such formalisms.