The metaphysical reason of this is, that where the figures are of great value and beauty, the mind is supposed to be engaged wholly with them; and it is an impertinence to disturb its contemplation of them by any minor features whatever. As the figures become of less value, and are regarded with less intensity, accessory subjects may be introduced, such as the thoughts may have leisure for. Thus, if the figures be as large as life, and complete statues, it is gross vulgarity to carve a temple above them, or distribute them over sculptured rocks, or lead them up steps into pyramids: I need hardly instance Canova's works,[63] and the Dutch pulpit groups, with fishermen, boats, and nets, in the midst of church naves. If the figures be in bas-relief, though as large as life, the scene may be explained by lightly traced outlines: this is admirably done in the Ninevite marbles. If the figures be in bas-relief, or even alto-relievo, but less than life, and if their purpose is rather to enrich a space and produce picturesque shadows, than to draw the thoughts entirely to themselves, the scenery in which they act may become prominent. The most exquisite examples of this treatment are the gates of Ghiberti. What would that Madonna of the Annunciation be, without the little shrine into which she shrinks back? But all mediæval work is full of delightful examples of the same kind of treatment: the gates of hell and of paradise are important pieces, both of explanation and effect, in all early representations of the last judgment, or of the descent into Hades. The keys of St. Peter, and the crushing flat of the devil under his own door, when it is beaten in, would hardly be understood without the respective gate-ways above. The best of all the later capitals of the Ducal Palace of Venice depends for great part of its value on the richness of a small campanile, which is pointed to proudly by a small emperor in a turned-up hat, who, the legend informs us, is "Numa Pompilio, imperador, edifichador di tempi e chiese." § XII. Shipping may be introduced, or rich fancy of vestments, crowns, and ornaments, exactly on the same conditions as architecture; and if the reader will look back to my definition of the picturesque in the "Seven Lamps," he will see why I said, above, that they might only be prominent when the purpose of the subject was partly picturesque; that is to say, when the mind is intended to derive part of its enjoyment from the parasitical qualities and accidents of the thing, not from the heart of the thing itself. And thus, while we must regret the flapping sails in the death of Nelson in Trafalgar Square, we may yet most heartily enjoy the sculpture of a storm in one of the bas-reliefs of the tomb of St. Pietro Martire in the church of St. Eustorgio at Milan, where the grouping of the figures is most fancifully complicated by the undercut cordage of the vessel.