Nor, in a merely artistical point of view, is it less important to note, that the greatest advance in power was made when painters had few subjects to treat. The day has perhaps come when genius should be shown in the discovery of perpetually various interest amidst the incidents of actual life; and the absence of inventive capacity is very assuredly proved by the narrow selection of subjects which commonly appear on the walls of our exhibitions. But yet it is to be always remembered, that more originality may be shown in giving interest to a well-known subject than in discovering a new one; that the greatest poets whom the world has seen have been contented to retouch and exalt the creations of their predecessors; and that the painters of the middle ages reached their utmost power by unweariedly treading a narrow circle of sacred subjects. Nothing is indeed more notable in the history of art than the exact balance of its point of excellence, in all things, midway between servitude and license. Thus, in choice and treatment of subject it became paralysed among the Byzantines, by being mercilessly confined to a given series of scenes, and to a given mode of representing them. Giotto gave it partial liberty and incipient life; by the artists who succeeded him the range of its scenery was continually extended, and the severity of its style slowly softened to perfection. But the range was still, in some degree, limited by the necessity of its continual subordination to religious purposes; and the style, though softened, was still chaste, and though tender, self-restrained. At last came the period of license: the artist chose his subjects from the lowest scenes of human life, and let loose his passions in their portraiture. And the kingdom of art passed away. As if to direct us to the observation of this great law, there is a curious visible type of it in the progress of ornamentation in manuscripts, corresponding with the various changes in the higher branch of art. In the course of the 12th and early 13th centuries, the ornamentation, though often full of high feeling and fantasy, is sternly enclosed within limiting border-lines;--at first, severe squares, oblongs, or triangles. As the grace of the ornamentation advances, these border-lines are softened and broken into various curves, and the inner design begins here and there to overpass them. Gradually this emergence becomes more constant, and the lines which thus escape throw themselves into curvatures expressive of the most exquisite concurrence of freedom with self-restraint. At length the restraint vanishes, the freedom changes consequently into license, and the page is covered with exuberant, irregular, and foolish extravagances of leafage and line.