The statement “art for art’s sake” means that true art has no any moral, didactic, religious, historical, social or utilitarian functions. It is also known as an approximate equivalent of Latin slogan “Ars gratia artis” used by American company Metro-Goldwyn-Mayer as opening credits.
The phrase can be applied to such movements of art as Abstract Expressionism and other forms of abstract art. Nevertheless there are still lot of opponents of it. Indeed it is quite difficult to separate art from any functions and meanings. While abstract artists create for art’s sake, their opponents try to connect art with life naming it and explaining possible variants of meaning. The subject is really controversial and pretty complicated. And to tell the truth I have never thought about it seriously.