Society requires that architecture not only communicate theaspirations of its institutions but also fulfill their practical needs. Differences in expression, apart from differences in planning, distinguish the forms of architectural types (the house from thechurch, etc.), the kinds of use (the Catholic from the Protestant church), and the traditions and customs of users (the English from the Swiss Protestant church). When architectural forms become the vehicles of content—in plan, elevation, and decoration—they are symbolic. Theirsymbolism can be understood consciously or unconsciously, by association (e.g., spire = church) to abuilding one has seen before and by the fact that it suggests certain universal experiences (e.g., vertical forms “rise”; low roofs “envelop”). One comprehends the meaning of symbols that are new, as well as those that are known, by association, because the laws of statics restrain builders from putting them into forms so completely unfamiliar that they do not suggest some tradition, just as the structure of language permits endless new meanings but retains a fairly constant vocabulary. The meaning of architectural symbols—or of words—may even change, but the process must be both logical and gradual, for, if the change is irrational, the purpose—communication—is lost.

The architectural plan, when used symbolically, communicates through its shape. From prehistoric times and in manycultures, thecircle, with its suggestion of the planets and othermanifestations of nature, gained a symbolic, mystical significance and was used in the plans of houses, tombs, and religious structures. By slow processes it came to be employed formemoria and shrines and for hero cults in both the East and the West. When building techniques permitted, its symbolism often merged with that of the dome. In Hindutemples, thesquare (and the cross plans developed from it) expressed celestialharmony. Thecentral-plan Christian church (circle, polygon, Greek cross, ellipse) fascinated the architects of theRenaissance with its symbolic and traditional values, and it is found in their drawings andtreatises to the virtual exclusion of the more practical longitudinal basilicas that architects were often commissioned to build.

Plan symbolism remained almost exclusively in the sphere of religion after antiquity, and its traditions gradually disappeared in the course of the 19th century. The modern plan is determined by problems of form (space-mass relationships, etc.) and by the practical demands of use rather than by symboliccommunication.

In elevation the most consistent symbolic forms have been thedome, thetower, thestairway, the portal, and thecolonnade. Domes imply the meanings of the circle and more, since a dome is a covering. Long before masonry domes could be built, the hemisphere was associated with the heavens as a “cosmic canopy,” and throughout history domes have been decorated with stars and astrological symbols. Inancient Rome and among Christians and Indian Buddhists, the dome came to mean universal power. During the Renaissance it spread from religious structures to palaces and government buildings, retaining some of itsimplications of power. In theUnited States the nationalcapitol is domed, and there are few state capitols without domes; the symbol has survived the loss of its original meanings. Thetower, with origins in early nature rites, has consistently symbolized power. The Chinesepagoda extends central-plan symbolism into towers; many towers and spires rose from the northern European Gothiccathedral, and themedieval Italian city was a forest of towers erected by nobles in constant competition to express their supremacy. This meaning survives in modern skyscrapers; their height is more frequently boasted of than theirefficiency or beauty.

Architectural elements conceived tofacilitate the use of buildings may also take on symbolic significance. Thestairway, employed in the past to give “monumentality” to important buildings, frequently became more expressive than convenient, especially in Baroque palaces.Portals, from the time of ancient Egyptiantemple pylons and Babylonian city gates, became monuments in themselves, used to communicate a heightened significance to what lay behind them. In the Gothic cathedral they became the richest element of the facade—a translation of biblical doctrine into stone. Since the development of the classical Greek temple, the colonnade on the exterior of buildings has borne similar implications.

Such symbols have becomearchaic in modernculture and appear as asign of resistance to new forms. This resistance is especially evident in the popular symbolism of domestic architecture, where the atmosphere of the home is often expressed by cottage-like roofs, shutters, trellises, mullioned windows, grilles, and other associations with a more peaceful past.

Decoration, the most easily recognized medium of content, communicates meaning either through architectural elements or through the figural arts (sculpture,painting,mosaic,stained glass, etc.). The architectural elements used decoratively, such as the classicalorders, usually originate in technique and in time lose their structural significance to become symbols. In ancient Rome and from the Renaissance to the 20th century, the formal Grecian orders were applied to buildings of many different techniques as expressions of the continuing influence of Greek institutions. Similarly, the new vocabulary ofGothic architecture, developed with new building techniques (the pointed arch, theflying buttress, etc.), became in later periods a source for religious andromantic symbolism. TheArt Nouveau of the turn of the 20th century, a system ofornament based on floral and other organic forms, survived for only two decades, perhaps because its symbols were neither drawn from a tradition nor derived from astructural system. (Architectural ornament will be further treated below.)

The function of the figural arts in conveying content is a subject outside the scope of this article, but its importance for architecture must be mentioned. The figural arts not only offer the means of expressing more specific ideas than any architectural symbols, but in many architectural styles they define the character of mass andspace. The sculptures of theHindu temple, the mosaics of theByzantine church, and the stuccoes of Moorish palaces are not ornamental applications; they determine the form of the building itself.

The virtual absence of traditional symbols in modern architecture is evidence of the failure of these symbols to express the cultural patterns of the 20th and 21st century. In these times, architecture, like painting, sculpture, and other arts, has tended to be abstract, to emphasize qualities of form rather than the communication of familiar ideas through symbols.