Harmony, therefore, though a necessary principle in all art, does not push herself to the front as does Principality. She follows naturally, if allowed to.
The Must Be's and May Be's of Composition
Of the other [principles], Consistency or breadth, Continuity and its complement, Contrast, associate themselves in greater or less degree with Principality and Harmony, which are the must [pg 270] be's; while Repetition, Radiation, Curvature and Interchange are reckoned as the may be's of composition.
Perspective
The basis of all plane presentation is founded on perspective, an absolute science giving absolute satisfaction to all who would have it. Knowing that a figure must be of a certain height if it occupy a given space is often a shorter road to the fact even though it demand a perspective working plan than feeling for it with the best of artistic intentions. One may feel all around the spot before finding it, and meanwhile the scientist has been saving his temper.
In all compositions demanding architectural environment or many figures, perspective becomes essential, at least as a time saver. Yet if the science never existed such art as embraces many figures and architecture could find adequate expression at the hands of the discerning artist.
The science of perspective does no more than acquaint the artist with any given angle. His knowledge of cause and effect in the universe, with an added art instinct, are equipment sufficient to obtain this.
No part of art expression commands more of the mysterious reverence of the atechnic than perspective. It is that universal art term that includes very much to many people. When, after writing a thorough treatise on the subject, Mr. Ruskin remarked the essence of the whole thing can be known in twenty minutes, it was doubtless [pg 271] in rebuke of the unqualified suppositions of the artless public.
Balance
The conception of balance clearly understood in the length, the height and the depth of a picture contains the whole truth of pictorial composition. The elements which war against unity and which we seek to extract, reveal themselves as the disturbers of balance and are to be found when the principles of balance are put into motion.