This letter, written by the architect Vittorio Gregotti to the philosopher Giorgio Agamben, was originally published in 1997 in the Italian Journal Rassegna, which Gregotti directed from 1979 to 1998. It is perhaps the very first time that a practicing architect and theorist discussed the concept of “biopolitics” in relation to architecture and urban planning, and it was translated from Italian to English by Anna Karla de Almeida Santos. Gregotti recalls that isolation is an old way of organizing the territory, through which the figure of the architect plays a distinct role by reproducing the “exception” as an ordinary design action. Such action constitutes “a tangible architectural rule” for organizing the human settlement. Here, the notion of exception is expressed in the “morphological and productive ways of organizing the city” and is oriented towards satisfying the inhabitants’ biological life—what the Ancient Greeks called zoè.