More concisely, the Beautiful is nature or art obeying the universal laws of perfect existence (i. e. Beauty), easily, freely, harmoniously, and without the display of power. The Picturesque is nature or art obeying the same laws rudely, violently, irregularly, and often displaying power only.
Hence we find all Beautiful forms characterized by curved and flowing lines-lines expressive of infinity, of grace, and willing obedience: and all Picturesque forms character ized by irregular and broken lines-lines expressive of violence, abrupt action, and partial disobedience, a struggling of the idea with the substance or the condition of its being. The Beautiful is an idea of beauty calmly and harmoniously expressed; the Picturesque an idea of beauty or power strongly and irregularly expressed. As an example of the Beautiful in other arts we refer to the Apollo of the Vatican; as an example of the Picturesque, to the Laocoon or the Dying Gladiator. In nature we would place before the reader a finely formed elm or chestnut, whose well balanced head is supported on a trunk full of symmetry and dignity, and whose branches almost sweep the turf in their rich luxuriance; as a picturesque contrast, some pine or larch, whose gnarled roots grasp the rocky crag on which it grows, and whose wild and irregular branches tell of the storm and tempest that it has so often struggled against.
Andrew Jackson Downing, A Treatise on the Theory and Practice of Landscape Gardening (1859), pp. 53-54. The metaphysical component, the "universal laws of perfect existence", which Downing takes to be imitative of divine attributes, is an interesting twist on the standard Gilpin-style theory of the picturesque, and seems to be at least partly derived from Ruskin.