Emmanuel Petit describes his 2013 book Irony; or, The Self-Critical Opacity of Postmodern Architecture as an extension of his interest in how new ideas of humanity lead to new urban forms. He finds the most compelling new human “spaces of coexistence” articulated in Peter Sloterdijk’s Spheres (1998-2004), which deals with successively wider areas of human engagement, from the personal “microsphere,” to “macrosphere” nations and global structures. Petit goes on to discuss postmodern architecture in terms of two other philosophers. The pre-Socratic Zeno of Elea provides a model of doubled spaces of paradox, which are seen in a range of divided house projects by a range of work that cuts across conventional historical categories. Søren Kierkegaard’s image of ironic presence-in-absence provides Petit with a way of understanding the seminal 1980 Presence of the Past exhibition, and other spaces haunted by meaning. Petit stresses that postmodernism’s self-criticality–it’s opacity–and awareness of incongruity are qualities very much needed in current architectural discourse.