What's in a symbol: ontology, representation
Sergei Nirenburg and Yorick Wilks
This paper is in a form unconventional in modern journals but
traditional for the discussion of foundational questions: a dialogue.
It is a form that makes it possible to contrast two deeply held but
incompatible views, each with its standard forms of defense, in order
to seek common ground and make the differences more precise. In
artificial intelligence, or at least in the major part of it still
committed to symbolic representations, there is a long history of
discussion of the origin and nature of the symbols we use in
representations, symbols which normally look like words, English words
in fact, but which most researchers deny are such words, since to
concede that would put in question the abstract nature of the
representation. In what follows, we examine our common ground and then
diverge over five specific questions on the issue of representations.
The discussion focuses on symbol use in representations of language,
because there the similarity is most acute -- between the
representation and the represented -- but the issues are general and
apply to symbolic AI as such.