Landscape designer Gilles Clément and architect Philippe Rahm present their contrasting visions through installations created specifically for the Canadian Centre for Architecture, and text and image-based essays outlining their philosophy and approach. Gilles Clément advances his theory of Tiers paysage, a ground-breaking approach to abandoned or overlooked spaces in cities and the possibilities they offer. Untreated by man, such spaces are home to a rich variety of species and are seen as crucial to sustaining biological diversity in the future. In the publication, Clément discusses his installation and further research on the theme of Tiers paysage based on the city of Montréal. Philippe Rahm's installation and essay "Form and Function Follow Climate" proposes a radical new way to address the use of energy in architecture. Rahm raises the possibility that climate and invisible aspects such as temporality, temperature, and humidity can replace typology, function, and spatial form in determining the way we use and define architecture. An essay by Giovanna Borasi situates the opposing positions of Clément and Rahm within a larger cultural context, and opens a new discussion on the place of humans in relation to the environment.