What is above laid down, will enable us to determine a very important question concerning emotions raised by the fine arts, _viz._ What ought to be the rule of succession; whether ought resemblance to be studied or contrast? The emotions raised by the fine arts, are generally too nearly related to make a figure by resemblance; and for that reason, their succession ought to be regulated as much as possible by contrast. This holds confessedly in epic and dramatic compositions: and the best writers, led perhaps by a good taste more than by reasoning, have generally aimed at this beauty. In the same cantata, all the variety of emotions that are within the power of music, may not only be indulged, but, to make the greatest figure, ought to be contrasted. In gardening there is an additional reason for the rule. The emotions raised by that art, are at best so faint, that every artifice should be used to give them their utmost strength. A field may be laid out in grand, sweet, gay, neat, wild, melancholy scenes. When these are viewed in succession, grandeur ought to be contrasted with neatness, regularity with wildness, and gaiety with melancholy; so as that each emotion may succeed its opposite. Nay it is an improvement to intermix in the succession, rude uncultivated spots as well as unbounded views, which in themselves are disagreeable, but in succession heighten the feeling of the agreeable objects. And we have nature for our guide, who in her most beautiful landscapes often intermixes rugged rocks, dirty marshes, and barren stony heaths. The greatest matters of music, have the same view in their compositions: the second part of an Italian song seldom conveys any sentiment; and, by its harshness, seems purposely contrived to give a greater relish for the interesting parts of the composition. A small garden comprehended under a single view, affords little opportunity for this embellishment. Dissimilar emotions require different tones of mind; and therefore in conjunction can never make a good figure[87]. Gaiety and sweetness may be combined, or wildness and gloominess; but a composition of gaiety and gloominess is distasteful. The rude uncultivated copartment of furze and broom in Richmond garden, hath a good effect in the succession of objects; but a spot of this nature would be insufferable in the midst of a polished parterre or flower-plot. A garden therefore, if not of great extent, will not admit of dissimilar emotions. And in ornamenting a small garden, the safest course is to confine it to a single expression. For the same reason, a landscape ought also to be confined to a single expression. It is accordingly a rule in painting, That if the subject be gay, every figure ought to contribute to that emotion.