 Dennett (1971) has put forward the notion of the intentional stance: the strategy of interpreting the behaviour of an entity by treating it as if it were a rational agent that governed its choice of action by a consideration of its beliefs and desires. As such it is an anthropomorphic instance of the so called design (functionality) stance, contra the physical stance, towards systems. This stance has been proved to be extremely influential, not only in cognitive science and biology/ethology (in connection with animal behavior), but also as a starting point of thinking about artificial agents.