Define your terms

The original question was not so much "what is art?" as which "subjects of taste" are art and which are not.  For example, ballet is an art form, gymnastics is a sport.  How about rhythmic gymnastics?  Neither one nor the other.  Ballet, gymnastics and even rhythmic gymnastics are practical skills guided by rules, human skill as opposed to nature.  But they are not all art forms.

There is a similar question to be asked about where craft ends and art begins.  Is a well designed chair a work of art or is it always just a seat?  Was Chippendale a craftsman or an artist? Alessi? Issigonis?  Is wallpaper art if it was designed by William Morris or Andy Warhol.  Is wallpaper art if you can buy it in B&Q?

Practical skill guided by rules.  What rules?  Who decides?  Did Joyce or Van Gogh have the rule book?  Human skill as opposed to nature.  Can a photo of a landscape ever be considered art?

Chamber's is a start but it hasn't really helped.  We'll try again tomorrow.

Warhol by Phil (oil on tarmac, 2012)