In the Formalities lecture series Robin Evans reviews aspects of composition with a view to finding out why those aspects are so often regarded as fundamental categories, and with a view also to showing how they interact with other kinds of phenomena. 'Modern architecture is more metaphorical than any other that there has ever been because it takes the things normally construed as being functional and construes them metaphorically'. Evans discusses the content and development of Le Corbusier's Modulor system of proportion and its relationship to the design and construction of Notre-Dame du Haut, Ronchamp. By distinguishing the ways in which the idea of the mechanical and rational manifests itself in terms of form and by tracing the return of descriptive geometry to modern architecture following the 19th century division between architecture and engineering, he attempts to clarify some of the issues surrounding the critical quest to comprehend Le Corbusier's creativity.NB: Two lectures.