Two months after the attacks of 9/11, the Bush administration, in the midst of what it perceived to be a state of emergency, authorized the indefinite detention of noncitizens suspected of terrorist activities and their subsequent trials by a military commission. Here, distinguished Italian philosopher Giorgio Agamben uses such circumstances to argue that this unusual extension of power, or "state of exception," has historically been an underexamined and powerful strategy that has the potential to transform democracies into totalitarian states.

The sequel to Agamben's Homo Sacer:...