One need not speak as categorically as Nietzsche, who thought the spread of irony throughout a culture always signified the floodtide of decadence and the approaching end of that culture's vitality and powers. In the post-political, electronically connected cosmopolis in which all serious modern artists have taken out premature citizenship, certain organic connections between culture and "thinking" (and art is certainly now, mainly, a form of thinking) may have been broken, so that Nietzsche's diagnosis no longer applies. Still, there remains a question as to how far the resources of irony can be stretched. It seems unlikely that the possibilities of continually undermining one's assumptions can go on unfolding indefinitely into the future, without being eventually checked by despair or by a laugh that leaves one without any breath at all.

-- Susan Sontag, The Aesthetics of Silence