This keeps popping up, so I thought I would throw in my two cents worth, well actually an art professor's two cents. I asked one who has years of experience in the classroom and is now a Dean of a university. Her opinion was that knives would fall under the same guidelines for art as sculpture. A knife can be art and judged as such. Some might be judged highly, while some would not. Just like a piece of rock or steel someone worked on and calls sculpture. I got the impression that some "art knives", to her, were busy looking and difficult to figure out what the maker wanted people to see, while some more simple, undecorated knives were classic examples of good sculpture. By her own admission she is very critical of "art". She is familiar with a wide range of custom and handmade knives since her husband is a collector. Her opinions and acceptance of knives as sculpture were a welcome surprise to me,