Of every subject Unity is the soul: unity, of course, is inseparable from legitimate chiaroscuro: hence the individual light and shade of every figure that makes part of a given or chosen subject, whether natural or ideal, as well as the more compound one of the different intermediate groups, must act as so many rays emanating from one centre and terminate, blazing, evanescent, or obscured, in rounding it to the eye. Truth is the next requisite of chiaroscuro, whatever be the subject. Some it attends without ambition, content with common effects; some it invigorates or inspires: but in either case, let the effect be that of usual expanded day-light, or artificial and condensed, it ought to be regulated by truth in extent, strength, brilliancy, softness, and above all, by simplicity in its positive and purity in its negative parts. As shade is the mere absence of light, it cannot, except from reflexes, possess any hue or colour of its own, and acquires all its charms from transparency. But to the rules which art prescribes to Chiaroscuro, to round each figure of a composition with truth, to connect it with the neighbouring groups, and both with the whole--it adds, that all this should be done with strict adherence to propriety, at the least possible expense of the subordinate parts, and with the utmost attainable degree of effect and harmony--demands which it is not my duty to inquire, whether they entered ever with equal evidence the mind of any one artist, ancient or modern: whether, if it be granted possible that they did, they were ever balanced with equal impartiality; and grant this, whether they ever were or could be executed with equal felicity. A character of equal universal power is not a human character--and the nearest approach to perfection can only be in carrying to excellence one great quality with the least alloy of defects. Thus in the School of Athens, Raffaello's great aim being to embody on the same scene the gradations, varieties and utmost point of human culture _as it proceeds from the individual to society, and from that ascends to God_; he suffered expression and character to preponderate over effect and combination of masses, and contriving to unite the opposite wings with the centre by entrance and exit at each extremity, as far as expression could do it, succeeded, to make what in itself is little more than apposition of single figures or detached groups, one grand whole.--I say, as far as expression could satisfy a mind qualified to contemplate and penetrate his principle, however unsatisfied a merely picturesque eye might wander over a scattered assemblage of figures equally illuminated and unconnected by a commanding mass of light and shade.