Sartre, in his 1960 critique of orthodox Marxism called Search for a Method, has an interesting comment about absent presences that reminds me of my last post about absent militaries, absent militantisms:
“The city is a material and social organization which derives its reality from the ubiquity of its absence. It is present in each one of its streets insofar as it is always elsewhere, and the myth of the capital with its mysteries demonstrates well that the opaqueness of direct human relations comes from this fact, that they are always conditioned by all others. The Mysteries of Paris stem from the absolute interdependence of spots connected by their radical compartmentalization. Each urban collective has its own physiognomy.” (p. 80 in the english translation)