I dwell on the necessity of completion especially, because I have lost much time myself from my sympathy with the feverish intensity of the minds of the great engravers; and from always fastening on one or two points of my subject and neglecting the rest.
18. We have seen, then, that every subject is to be taken up first in its terminal lines, then in its light and shade, then in its color.
First of the terminal lines of landscape, or of drawing in outline.
I think the examples of shell outline in your copying series must already have made you feel the exact nature of a pure outline, the difficulty of it, and the value.
But we have now to deal with limits of a more subtle kind.
The outline of any simple solid form, even though it may have complex parts, represents an actual limit, accurately to be followed. The outline of a cup, of a [shell], or of an animal's limb, has a determinable course, which your pen or pencil line either coincides with or does not. You can say of that line, either it is wrong or right; if right, it is in a measure suggestive, and nobly suggestive of the character of the object. But the greater number of objects in a landscape either have outlines so complex that no pencil could follow them (as trees in middle distance), or they have no actual outline at all, but a gradated and softened edge; as, for the most part, clouds, foam, and the like. And even in things which have determinate form, the outline of that form is usually quite incapable of expressing their real character.
19. Here is the most ordinary component of a foreground for instance, a pleasantly colored stone. Any of its pure outlines are not only without beauty, but absolutely powerless to give you any notion of its character, although that character is in itself so interesting, that here Turner has made a picture of little more than a heap of such stones, with blue water to oppose their color. In consequence of these difficulties and insufficiencies, most landscape-painters have been tempted to neglect outline altogether, and think only of effects of light or color on masses more or less obscurely defined. They have thus gradually lost their sense of organic form, their precision of hand, and their respect for limiting law; in a word, for all the safeguards and severe dignities of their art. And landscape-painting has, therefore, more in consequence of this one error than of any other, become weak, frivolous, and justly despised.
20. Now, if any of you have chanced to notice at the end of my "Queen of the Air," my saying that in landscape Turner must be your only guide, you perhaps have thought I said so because of his great power in melting colors or in massing light and shade. Not so. I have always said he is the only great landscape-painter, and to be your only guide, because he is the only landscape-painter who can draw an outline.
His finished works perhaps appear to you more vague than any other master's: no man loses his outlines more constantly. You will be surprised to know that his frankness in losing depends on his certainty of finding if he chooses; and that, while all other landscape-painters study from Nature in shade or in color, Turner always sketched with the point.