By retaining the traces of past and future—a past and future it nonetheless transforms—the photograph sustains the presence of movement, the pulses whose rhythm marks the afterlife of what has been understood, within the movement it gorgonizes. Only when the Medusan glance of either the historical materialist or the camera has momentarily transfixed history can history as history appear in its disappearance. Within this condensation of past and present, time is no longer to be understood as continuous and linear, but rather as spatial, an imagistic space that Benjamin calls a ‘constellation’ or ‘monad.’ — Eduardo Cadava, Words of Light: Theses on the Photography of History (Princeton, N.J: Princeton University Press, 1997), 60.