As has been suggested, proportion, in its character, is not only simple but complex, and its effects cannot be produced on a large scale without the most careful and profound study. These effects, too, are still capable of further development. The forms of Greek, Gothic, Moorish, Romanesque, or Renaissance art have no more exhausted the possibilities of architecture than analogous developments in poetry, painting, or music. In this land and age, we can, and should, have an architecture of our own, to meet the requirements of our climate, as the Greek may not; of our customs, as the Gothic may not; and of our artistic instincts, as the Queen Anne may not. Such an architecture can be thoroughly original, yet if, in trying to make it so, we neglect the principles according to which the minds that are to view it must judge of it, we cannot expect it to commend itself to general approval, even in our own times, and much less in coming times. Whatever may be the nature of his designs, the architect who deals with shapes must remember that shapes fill space just as sounds fill time, and that for the purposes of art the appearances of similarly related measurements in the one are as necessary as in the other. In short he must never forget that which it has been found necessary to repeat so many times already, that the fundamental principle in art is to group sizes as well as shapes by putting together those that, if not as wholes, in parts at least, can be made to seem alike.Proportion and Harmony of Line and Color, XIII.
When a style is just beginning to be developed, a builder, having learned nothing from his own experience or that of others, necessarily makes mistakes. His work is the expression of his thought. It is original; but not always artistic. Much later on, in the development of the style, precisely the opposite condition is found. The highest conception of the builder seems to be that his forms should be modelednot partly, which would be unobjectionable, but entirely,upon those of preceding buildings, ancient or modern. These preceding buildings are either wholly copied by him, in which case the new product is a mere imitation; or else several different buildings are copied in part and in part combined with other forms that he originates; in which case, because the method in accordance with which such forms as he combines were brought together by the earlier architects is not known, often not even studied, his new product is incongruous. Its effects are produced with too little regard for the considerations which must have influenced those who produced the original forms which are imitatednamely, the requirements of the design of the building and of the eye and mind as affected by great natural laws like those of propriety, proportion, and symmetry.