Norberg-Schulz does not view architecture in isolation. Instead, he constructs an "intellectual edifice" by weaving together diverse scientific and philosophical disciplines:
In the post-war era, architectural theory was largely dominated by the legacy of the International Style and the functionalist maxim "form follows function." By the early 1960s, however, a growing dissatisfaction with the sterile universality of Modernism began to emerge. It was in this climate that Christian Norberg-Schulz, a Norwegian architectural theorist, published Intentions in Architecture (1963).
If you have just located the PDF, do not read it like a novel. Norberg-Schulz writes in dense, German-accented English. His sentences are long, and his references (to Piaget, Merleau-Ponty, and Gibson) are rapid.