Marcus will present MaterialNatures at ACSA. Over the last century, two paradigms have dominated attempts at dealing with the challenges of the city. On one hand, a "substantive" approach that aims to control the physical substance of the city, treated as a completely predetermined object: form and life dictated by some architects who claim a universal understanding of the goals and values of society to which they incorporate the advances of science in order to improve the conditions of the city. On the other, a "procedural” or strategic approach where the focus is on the process, better understood as a form of social action, a negotiated creation involving many stakeholders with overlapping or competing interests in the process of developing visions, identity and, of course, physical projects. The substantive and the procedural are not antagonistic concepts, but two different approaches to controlling the evolution of urban space. Furthermore, in the context of the city as a collective production that is at the same time poetic and pragmatic, the distinction of the procedural and the substantive is inevitably subsumed by the “practice” of city building as distinct from city design.