What is Art?
This is the age old question artists and critics have bantered around since before writing.
Leo Tolstoy wrote an essay about it called What is Art?.
"A large part of the beauty of a picture arises from the struggle which an artist wages with his limited medium." - Henri Matisse
"Art is a man made object that is created to release an emotion from the artist and to invoke an emotion in a viewer." - Colin Kaminski
A very informative treatment can be found in Maragret Benyon's Holography as Art