The traditional role of the architect as "master builder" has required him to assimilate knowledge from many different disciplines. The question is sometimes raised as to whether architecture as a distinct discipline has a theory of its own, or whether it is merely an amalgamation of theories borrowed from other disciplines. Architecture involves "hard" sciences such as structures, acoustics, thermodynamics, physiology and psychology, as well as "soft" sciences such as sociology, philosophy, and aesthetics. Inasmuch as the whole is more than the sum of its parts, architecture does have a distinct theoretical base, but it is perhaps not as concise or as mathematically precise as the theories of engineering disciplines. The integration of theories from associated disciplines mirrors the role of the architect as the integrator of the built environment. This chapter rests heavily on architectural theory as put forth by Hesselgren , Prak , Thiis-Evensen , Norberg-Schulz , Scully , and Banham . Other sources are cited where appropriate.
Hesselgren's starting point is perception psychology. We do not "know" the external physical environment - we can only detect it from its effects on our sense organs. These sensations and perceptions are studied, through the method of phenomenology, as entities distinct from the physical stimuli that give rise to them: we "see" not with our eyes, but with our minds. Hesselgren illustrates this point with numerous examples of visual illusions, in which the perception is clearly at odds with the stimulus. He gives particular attention to visual perceptions, as they are the easiest to convey on the printed page, but he discusses other modalities as well: tactile, haptic, kinesthetic, auditive, and olfactory (smell and taste). There are "transformation tendencies" between these modalities - for example: a perception of visual texture gives rise to a mental image of tactile grain. Building up from this foundation, he draws on Gestalt psychology to examine how perceptions evoke meanings that are subject to autonomous aesthetic evaluations. These evaluations are - in various degrees - formal, semantic, and emotional. Architectural theory is primarily concerned with evaluations that are spontaneous and common; those that are private or individualistic are of less theoretical interest. The expression of meaning in built form that serves practical function is what distinguishes architecture from both engineering and sculpture. Hesselgren ends with a discussion of architectonic room and "townscape", which he characterizes as "the unit of highest dignity which can be found in architecture" .
Prak's approach is similar but complementary. Like Hesselgren, he bases his theory on aesthetic evaluations rooted in the psychology of perception. He begins with a discussion of formal and symbolic aesthetics as they apply to architecture, and shows how rules of composition may transcend period and style. Working somewhat reverse to Hesselgren, Prak moves from aesthetics, to symbolism, basic architectural concepts (place, space, and structure), and classification of forms based on gestalts. While Hesselgren concentrates on the analytical development of architectural theory, Prak by comparison summarizes the essential points and devotes most of his attention to practical application illustrated by historic examples. An important hypothesis in Prak's analysis is that architectural aesthetics are a subconscious emotional reaction to prevailing social conditions. (For example: the gradual progression of medieval sculpture from abstraction to realism was due not to rediscovery of lost classical skills, but rather to growing economic and political stability that made reality more attractive.)
Thiis-Evensen focuses on elements of composition that contribute to existential expression of shared experience. He identifies three qualitative concepts that form the basis of this expression: motion, weight, and substance. If we decompose "weight" into its more universally applicable constituents of "force" and "mass", these concepts evoke Newton's Laws - regarding the motion of mass - along with the principle that a substance occupies a unique and distinct position in space and time. Thus, they form a good foundation for shared experience. Thiis-Evensen is concerned not with their mathematical description, but rather with their aesthetic expression. He describes an architectural grammar based on three elements - floor, wall, and roof - and four levels of expression - major form, construction system, surface treatment, and openings. "On each of these levels ... clearly defined archetypes exist which represent general solution to problems of form that remain the same regardless of time, place, or function" . Thiis-Evensen defines a "vocabulary" of these formal archetypes, and describes their shades of meaning and appropriate application.
Norberg-Schulz takes the existential philosophy of Martin Heidegger as a catalyst to studying the phenomenology of environment and "spirit of place". Like Hesselgren and Prak, he makes reference to Gestalt principles, but he forgoes detailed discussion of basic perception psychology and concentrates instead on the higher-level emotive symbolic aspects of natural and man-made environments :
Being qualitative totalities of a complex nature, places cannot be described by means of analytic, "scientific" concepts. As a matter of principle science "abstracts" from the given to arrive at neutral, "objective" knowledge. What is lost, however, is the everyday life-world, which ought to be the real concern of man in general and planners and architects in particular ... Poetry in fact is able to concretize those totalities which elude science, and may therefore suggest how we might proceed to obtain the needed understanding.
Modern tourism shows that the experience of different places is a major human interest. Qualities of the earth and sky - such as variability of terrain, degree of closure or extensibility, clearness of atmosphere, angle and intensity of sunlight - combine to create the local character. Like Thiis-Evensen, Norberg-Schulz focuses on the existential expression of shared experience. He structures his presentation around three archetypes of natural and man-made place - "romantic", "cosmic", and "classical" - and provides detailed analyses of three prime examples - Prague, Khartoum, and Rome. Of the three, Khartoum - the oasis in the desert - is most evocative of a self-contained space settlement. Notably, Norberg-Schulz describes it as "cosmic", even though he never conceives of dwelling anywhere but "on the earth", "under the sky".
Scully, like Norberg-Schulz, is concerned with the spirit of natural and man-made places, but focuses particularly on the right relationship between the natural and man-made. Echoing the sentiments of Hesselgren on architectonic room and townscape, Scully maintains that "the relationship of man-made structures to the natural world offers, in my view at least, the richest and most valuable physical and intellectual experience that architecture can show" . He traces this relationship through a historical review of places and styles, emphasizing the ways in which nature shapes the culture that shapes the architecture.
Banham traces the theoretical development of modern architecture through "the first machine age", approximately 1850-1950. During this time, new technology for production, transportation, and communication became available to the common people and radically transformed patterns of life that had remained unchanged for thousands of years. In contrast to Scully, Banham focuses on the relationship between architecture and technology, with an emphasis on the evolving priorities of form and function. He examines the philosophical foundations and subsequent development of modern architecture through the writings, teachings, and designs of its leaders.
Compared to the literature on Newtonian physics or mechanical dynamics, these discourses on architectural theory are quite diverse. Yet, there are common threads of thought that tie them together. These commonalities are profound precisely because they are manifest in so many different theoretical approaches and points of view. The next several sections highlight a few of these threads that seem particularly relevant to extraterrestrial architecture.