... the mainstream can tolerate and even requires a certain amount of naughty avant-garde art works that shock, criticize, provoke and attack corporate assumptions, in order to claim legitimacy in historical terms. But, there are precise limits to what can be done and promoted for profit, and they are tightly drawn. Any serious, non-ironic invocation of socialism will be ignored by the marketplace. Or any serious invocation of actual revolution, under the aegis of any ideology. Or any serious invocation of a future that does not include capitalism as its centerpiece. The list is long, but little discussed in public—that, too, is avoided by artists and critics who adopted long ago a self-censoring caution, lest they be considered terrorist sympathizers or otherwise unfit for the marketplace.