From these two examples of their general effect, some notion may be gathered of the different systems of the two Artists; and though no mention has been made of the particular lines employed, their distinctive character may readily be inferred from the kind of motion given to the eye in the descriptions we have attempted. In the rapid, abrupt, contrasted, whirling movement in the one, we have an exposition of an irregular combination of curves and angles; while the simple combination of the parabola and the serpentine will account for all the imperceptible transitions in the other.
It would be easy to accumulate examples from other Artists who differ in the economy of line not only from these but from each other; as Raffaelle, Michael Angelo, Correggio, Titian, Poussin,--in a word, every painter deserving the name of master: for lines here may be called the tracks of thought, in which we follow the author's mind through his imaginary creations. They hold, indeed, the same relation to Painting that versification does to Poetry, an element of style; for what is meant by a line in Painting is analogous to that which in the sister art distinguishes the abrupt gait of Crabbe from the sauntering walk of Cowley, and the "long, majestic march" of Dryden from the surging sweep of Milton.
Of Continuity little needs be said, since its uses are implied in the explanation of Line; indeed, all that can be added will be expressed in its essential relation to a _whole_, in which alone it differs from a mere line. For, though a line (as just explained) supposes a continuous course, yet a line, _per se_, does not necessarily imply any relation to other lines. It will still be a line, though standing alone; but the principle of continuity may be called the unifying spirit of every line. It is therefore that we have distinguished it as a separate principle.
In fact, if we judge from feeling, the only true test, it is no paradox to say that the excess of variety must inevitably end in monotony; for, as soon as the sense of fatigue begins, every new variety but adds to the pain, till the succeeding impressions are at last resolved into continuous pain. But, supposing a limit to variety, where the mind may be pleasurably excited, the very sense of pleasure, when it reaches the extreme point, will create the desire of renewing it, and naturally carry it back to the point of starting; thus superinducing, with the renewed enjoyment, the fulness of pleasure, in the sense of a whole.