In architecture, to composemeans to conceive of a building according to the principles of regularity and hierarchy, or according to the principles of the creation of equilibrium. Still, it was only in the 19th century that composition truly began to mean architectural conception, notably thanks to Jena-Nicholas-Louis Durand and his statement on the Marche à suivre dans la composition d'un projet quelconque (Method for the composition of projects in general). This concept rapidly wears out during the course of the 20th century with the arrival of attempts to move beyond compositional principles, such as the adoption of neutral architectural systems, the use of aggregating processes, and the development of "objective" operations. Composition Non-compositioninvites the reader to discover this untold history of architectural theory. This work offers insight into attitudes that are often in conflict with each other, as well as into the obliteration of certain concepts and the emergence of others. The book provides many original keys to understanding contemporary architecture and thus offers an instructive reference for students in architecture and for architects.