This is a book series for the fith edition of Lisbon Architecture Triennale. A unique and limited collection edited by the curatorial team of The Poetics of Reason: a sparkling intellectual reflection from a three-year investigation on architectural rationality. With stunning visual references, these five books explore the various subjective and non-scientific dimensions of architecture with contributions from architects, philosophers, artists and acclaimed authors. ECONOMY OF MEANS Form is the horizon of any human activity. Architecture is a discipline aiming at defining the form of buildings. Economy of Means : How Architecture Works aims at defining the good architectural form. Economy of means is its D.N.A. Beyond this, by questioning the economy of means both as an aesthetic category and as a conceptual tool, the book proposes to renew architecture to face global warming and scarcity of resources from within the architecture discipline. WHAT IS ORNAMENT? The book is organized as a reader: a collection of contributions, ranging from Vitruvius to the current day dealing, in different ways with the debate around ornament. Exploring patterns, intended as regularly repetitive arrangements reflecting the time and the society in which they are conceived; looking at information superstructures like texts, frescoes and screens, when they become the main instrument to compose a building; enlarging ornament to the whole urban environment, embracing the complexity of shared space and imagining it as a scene for the development of public life. INNER SPACE Inner Space is part of an ongoing research project into the construction of the architectural imagination, which the authors have pursued in the last decade through an online visual atlas (socks-studio.com), an architectural practice and teaching activity. This essay investigates the space between inner and outer reality, looking for those moments in which the two realms interact most vividly. TAKING THE COUNTRY?S SIDE. AGRICULTURE AND ARCHITECTURE Are metropolises really the ?manifest destiny? of humankind? Is the environmental predicament calling for more concentration and incorporation? Or is it conducive to some kind of urban exodus? By and large, what might be the principles and ethics of design in such a condition? These are some of the issues that this book addresses. NATURAL BEAUTY On the one hand, the publication takes the form of a series of statements on architecture, construction, rationality and photography. On the other, it proceeds as a photographic essay of Tatiana Macedo, that gathers side by side constructive forms, taking advantage of the structure of a book.