Ethics and Authenticity

This summer I had the opportunity to attend a workshop led by well known artist/philosopher/physicist Enrique Martinez Celaya. The topic of discussion was "the challenges of making art in the age of careerism and art funds." It was a fascinating discussion that ranged over vast topics including philosophy, ethics and authenticity in art.
It was a difficult discussion to follow where every assumption made about definitions or concepts concerned were challenged. Mr. EMC as I like to refer to him (eMC2) did a comparison between the works and talent of Velásquez and Rembrandt, suggesting that perhaps Rembrandt lacked subtleness. His talent was visibly displayed in full glory on the canvas to impress. Velásquez on the other hand revealed his complexity and subtleness by what he didn't paint on the canvas.
The main idea that was consistently generated was "Why do you do art? and "Is this really art or just decoration?", "What is art?" The discussion generated many thoughts and questions such as "If someone gets paid big bucks for their art, does that legitimize it as art?"
I've been digesting the discussions throughout the summer and have decided to turn to the philosophers of old for some background and guidance, Satre, Heidegger, Hume, Kant....