It is all about inspiration that would categorize a piece of art. When I want to create art without the inspiration it will never happen. If inspiration is not strong enough art doesnt get finished. A "block" needs to be overcome with reinspiration. An interesting observation of early art reveals that inspiration of that artist was his need to express with pictures to tell the story of his hunt or what type of animal could be found at a scene of a hunt. That early artist created intentional and representational art not thinking into the future how today's critics would view the drawings.
The art field has widened today to include artifacts that have been found that were actually tools, weapons and utensils. These were not intended to be art by the maker, but are important as art because of the skills used by that person. Some of the tools created today will likely be art in a distant future.
My personal definition of art is all about the inspiration. An inspired human creates work that is representational of his idea into a format to be used or studied by others.