Self-supporting structures of intellectual bureaucracy, built on mud. They keep their integrity even as they're sinking. More examples:

"Picasso not only worshiped the gods Dionysius, Priapus and Mithra..."

In about ten years of crisis during which it's been made clear he hardly understood what he was doing, Picasso made the most important series of paintings in the 20th century and some of the most important art from that century in any medium. But that was bracketed by periods of adolescent sentimentalism, mannerism, and kitsch. The grandiose statements reflect increasing insecurity; the confidence rings embarrassingly false.
"Picasso used to be a great painter, now he is merely a genius." It's doesn't make Braque a better painter to agree.

I'm not in the mood to make the longer argument.