In The Semantic Web, Syllogism, and Worldview, Clay Shirky debunks the notion of semantic web — the short of it is the problem of semantics is hard; the trivial use cases that have been proposed to date don’t scale and aren’t that useful any way. Spend a couple of months studying the history of knowledge representation (from artificial intelligence, back through math and philosophy) and you’ll find that this is problem with a long history and little progess.
One thing in Shirky’s article that’s not quite right: He gives an example of how syllogisms fail that’s not quite right:
Consider the following assertions:
- Count Dracula is a Vampire
- Count Dracula lives in Transylvania
- Transylvania is a region of Romania
- Vampires are not real
You can draw only one non-clashing conclusion from such a set of assertions — Romania isn’t real.
You wouldn’t conclude Romania isn’t real unless all the predicates had been “is a”. This does, however, highlight another problem of semantics: how do you come to a shared, complete, and consistent set of predicates well defined inferential properties.