It's an old question: What is art? What is "good" art? Do you love the art because it appeals to you or just because it's in an art gallery? It's not just about beauty, because some of the world's most famous artworks are quite ugly or horrific.
There's also the question of "real" art versus "fakes". Is the art of any less value if the brush was wielded by one of Rembrandt's students rather than the master himself? Does knowing whether a work is authentic add to your appreciation?
The new ABC Radio National show, Books & Arts Daily, recently ran an interview with Professor Martin Kemp about his research with neuroscientists into how the brain responds to "authentic" and "fake" art. Listen here. Fascinating!