Hildebrand claims to have uncovered some deep motives that apply to most of Wrights houses which may explain why they are so extremely popular. He bases these motives on notions first identified and defined by Jay Appleton. Appleton noted that prospect and refuge are two conditions that have deep appeal to humans. Prospect means the potential of a site of offering a sight covering a considerable distance. Refuge means the potential of providing a hiding-place. Having both a sense for prospect and refuge aids in survival, when one is attracted to find places which enable to see but not to be seen.

Following Appleton in this mode, Hildebrand founds architectural analysis on human cognition and psychology. In order to further his apparatus of analysis he includes other factors that seem to have an influence well established: complexity and order. Complexity meets man's desire for changing impulses, while order satisfies his need for recognizing regularities and commonalities. Next to these factors, which Hildebrand readily sees applicable to Wrights houses, he identifies two other factors which are less pervasive: hazard and mystery. Hazard indicates a condition which might be threatening while mystery indicates a situation where other spaces are suggested but not revealed.

The key to both Hildebrand and Appleton is, that these traits have been and are so fundamental for man's survival, that they are inherently structured in his genetic make-up. Thus, these factors need not be consciously aware of in order for them to operate and assure survival. The control-structure present to exercise this influence is, as with other survival behaviors like eating and copulation, the inherent pleasure they give. Thus meeting these fundamental needs is satisfying.

Appleton developed his theory for landscape architecture, and it is Hildebrand's merit to recognize their potential value for architecture. He argues that the same factors which influence appreciation in landscape-sites and settings, also operate when apprehending the built environment. Furthermore, he claims that Wright in his designs has applied these factors in a consistent pattern which leads to a joint appreciation by both clients and colleagues.

In "The Wright Space" he sets out to analyze Wright's Prairie Houses, both Taliesin complexes, California Houses, Fallingwater, and the Usonians. He transforms the landscape concepts to architectural concepts and applies them on Wright's work, which he demonstrates in clear diagrams, drawings, and photo's. Not only makes he plausible the presence of the concepts mentioned, but he also shows they form a coherent and consistent pattern in most of Wrights houses between 1902 and 1950 (Hildebrand mentions Taliesin West and Ocatillo camp as the only exceptions in which the pattern does not fully show).

Wright's houses had and still do have "conspicuous faults". Hildebrand: "Many of Wright's plans defy reasonable furniture arrangements, many frustrate even the storage of reasonable and treasured possessions. In many cases, severe problems afflict the architectural fabric: leaking roofs, unserviceable detailing, even structural inadequacies. A number of the houses were over budget to a degree that challenges belief. And, one must add, there were problems of personality as well: it is a matter of record that many of Wright's clients found him arrogant, careless, slow, and misleading, and were not by any means amused by his temperament." Hildebrand argues that they still have such strong appeal because these houses display in a unique interplay the pattern that meets the strong unconscious factors of refuge, prospect, complexity, order, hazard, and mystery.

Hildebrand generalizes his ideas and tests them against other architects. He deals with Wright's contemporaries like Charles Rennie Mackintosh, Henry Mather, Charles Sumner Greene, as well as Prairie School architects and followers like Richard Neutra to show that the outstanding quality of Wright's work is not a matter of outside style, but of the degree of applying the pattern. He argues that it is possible to realize the pattern without returning to the typical Wrightian architectural means to realize the pattern. In order to demonstrate this, he analyzes Wendell Lovett's work and Mario Botta's houses.

"The Wright Space" forwards Hildebrand's case through a clear and very readable text, a multitude of beautiful black-and-white contemporary photo's of Wright's work, provides well drawn plans, and illuminating diagrams. He outlines an interesting and plausible theory which proves to be significant for current design.