Today I went with a friend to see Tate Britain’s “Art Under Attack” show. It’s an interesting, if uneven, affair that entertains but doesn’t quite succeed in everything it attempts to do. The big word that you learn is iconoclasm: the act of attacking an object believed to represent particular beliefs. The show splits into two parts: ideological acts of iconoclasm committed against works of art in Britain and the work of British artists who embrace iconoclasm as a means for making art.