Although in philosophical literature the notion of an agent as a cognitive subject has been around for a long time, in the last decade or so the area of ‘Intelligent Agents’ has also become a major area of research within artificial intelligence and computer science, an area with a big promise as there are a myriad of possible applications (see e.g. [4]). As might be expected, within the latter areas the concept of an agent generally has a more technical meaning, although there is no general consensus on its definition. But mostly by an agent is meant a (software or hardware) entity that has some degree of autonomy, which typically comes down to displaying reactive and/or proactive behaviour (that is to say that the agent is capable of reacting to its environment and taking initiative, independent of the user, respectively), might possess reasoning and learning capabilities, and is able to communicate in some intelligent way with other agents. Sometimes agents are ascribed ‘mental attributes’ such as a mental state comprising knowledge, belief, Whether these mental attributes are merely metaphorical (i.e. a convenient means of describing agents) or ‘real’ in the sense that these artificial agents possess some ‘truly cognitive’ capabilities like human or, to a lesser extent, animal agents do, is of course a matter of philosophical debate but also a question depending to a large extent on the application one has in mind.