Andrea Branzi was among the first architects to incorporate the philosophical postmodernity -as it was formulated by Jean-François Lyotard and, soon after, by Gianni Vattimo- into his discourse. In the early 80’s the Italian philosopher puts forward the pensiero debole (weak thought): a philosophy meant to be consistent with this new situation marked by an ahistorical condition, a fragmented and babelian scenario, and the weakening of being. Branzi not only brings this new intellectual framework to his discourse very early, but also translates it to the architectural field in an extremely clear and explicit way through many of his writings and, above all, via his "models of weak urbanization." Urban proposals marked by fragmentation, instability and lightness and where a process of dissolution of architecture -that is perfectly analogous to the dissolution of being described by Vattimo- takes place: The open and adaptable structures of these cities represent a kind of ontologically attenuated architecture that relates to the canonical architectural object like the ‘weak being’ relates to the strong, metaphysical being in the philosopher’s discourse. However, despite the undeniable adherence of the architect’s work and discourse to pensiero debole, the relationship between Branzi and Vattimo is far from being the simple and mere absorption of an intellectual corpus that was absolutely alien until that point. Quite the contrary, it proves to be very revealing about the invariants that Branzi has stubbornly kept throughout his long career and, more broadly, about how architects relate to their cultural environment.