Painting the face of a pretty young girl is like carving a portrait in silver. There may be great elaboration, but no likeness will be forthcoming. It is better to put the elaboration into the young lady's clothes, and trust to a touch here and a stroke there to bring out her beauty as it really is.
_Ku K'ai-Chih_ (Chinese, fourth century).
Portraiture may be great art. There is a sense, indeed, in which it is perhaps the greatest art of any. And portraiture involves expression. Quite true, but expression of what? Of a passion, an emotion, a mood? Certainly not. Paint a man or a woman with the damned "pleasing expression," or even the "charmingly spontaneous" so dear to the "photographic artist," and you see at once that the thing is a mask, as silly as the old tragic and comic mask. The only expression allowable in great portraiture is the expression of character and moral quality, not of anything temporary, fleeting, and accidental. Apart from portraiture you don't want even so much, or very seldom: in fact, you only want types, symbols, suggestions. The moment you give what people call expression, you destroy the typical character of heads and degrade them into portraits which stand for nothing.
It produces a magnificent effect to place whole figures and groups, which are in shade, against a light field. The contrary, _i.e._ figures that are in light against a dark field, cannot be so perfectly expressed, because every illuminated figure, with or without a side light, will have some shade. The nearest approach to this is when the object so treated happen to be very fair, with other objects reflecting into their shades.
Shade against shade is indefinite. Light and shade against shade are mediate. Light against shade is perspicuous. Light and shade against light is mediate. Light against light is indefinite or indistinct.
Most of the masters have had a way, slavishly imitated by their schools and following, of exaggerating the darkness of the backgrounds which they give their portraits. They thought in this way to make the heads more interesting, but this darkness of background, in conjunction with faces lighted as we see them in nature, deprives these portraits of that character of simplicity which should be dominant in them. This darkness places the objects intended to be thrown into relief in quite abnormal conditions. Is it natural that a face seen in light should stand out against a really dark background--that is to say, one which receives no light? Ought not the light which falls on the figure to fall also on the wall, or the tapestry against which the figure stands? Unless it should happen that the face stands out against drapery of an extremely dark tone--but this condition is very rare, or against the entrance of a cavern or cellar entirely deprived of daylight--a circumstance still rarer--the method cannot but appear factitious.