Contemporary architectural theory emphasizes the importance of "tectonics," the term used to articulate the relationship among construction, structure, and architectural expression. Yet, little consideration has been given to the term's origins or historical significance. In this study, Oechslin examines the attempts by early Modern theoreticians of architecture to grapple with the relationship between appearance and essence. He locates the culmination of this search for "truth" in architectural expression in the work of Adolf Loos and the writings of theorists such as Bötticher, Le Corbusier, and Lux.