The course makes a systematic overview of the most common key concepts that appear during the architectural design process. The aim is to offer a solid theoretical and philosophical background for their use and to present ways that these concepts are interpreted by various architects in different historical periods. Methodologically, the course presents these concepts in pairs or dipoles proposing, thus, that as the architect designs, consciously or unconsciously, she keeps on making decisions that place her lines in a tensed conceptual field that characterize each work. The students are expected to execute an analysis of an existing building based on these pairs of concepts, explaining thus the way that each of them contributes in the design process.