Universal, Eternal, and Unfree?

“The subject is to the painter what the rails are to the locomotive. He cannot do without it. In fact, when he refuses to seek or accept a subject his own plastic methods and his own aesthetic theories become his subject instead. And even if he escapes them, he himself becomes the subject of his work. He becomes nothing but an illustrator of his own state of mind, and in trying to liberate himself he falls into the worst sort of slavery.” -Diego Rivera

This is a useful antidote to my old fantasy of art uncorrupted by any situational particularity of space or time. Purity becomes slavery, just as Said said (ha) about aestheticism in literature. Or am I wrongly conflating the notion of art for art’s sake with that of decontextualization? For me at least they are the same.