Discussion of domains

There are two things to notice about domains which were not true with regards to type. First, many entities in the world are best represented as a set of cross-domain concepts within this knowledge system. For example, consider Professor Hugo from Zoo.   Hugo is a person, which is a kind of physical agent. He is also a showman, which is a social agent. A reader of the story might wish to view him as a con artist as well; this would introduce another social agent to his description. Similarly, actions are often a combination of several domains. Characters in the story gave money to Hugo. At one level, this represents a physical action of transferring money from one agent to another. However, the customer agent aspect of the characters are engaging in a social action whereby they are purchasing the right to view the animals in the zoo. There is one action described in the text; to comprehend it requires viewing it as existing within two domains at the same time.

Second, notice that the lexical relationship which existed for types of entities does not hold when discussing domain. There are no lexical tags which allow a reader to determine the proper domain in which to place a portion of a text. For example, consider John blocked Bill. This might be a physical action or a social action; it is impossible to tell from the lexical tagging of the sentence.

Finally, as with the types of entities, there is research which indicates the domain distinction is one which human reasoners possess. Early in cognitive development, there is a division made between the physical and the non-physical   ([#!change:carey1!#,#!change:carey2!#]). This occurs later in growth than the earlier division between objects and events. Additionally, a number of researchers   (see, for example, [#!phil:johnson1!#]) have suggested that at least three domains of entities exist in the world--there is a physical domain, capturing the well-known physical world around a reasoner; the psychological domain, which involves internal mental and emotional structures, such as ideas; and a temporal domain, involving aspects related to time.