The great masters of the Middle Age had set themselves to express in stone or colour the delicate beauty of the soul, its terror, too, in the loneliness of the world, where only as it were by chance it might escape everlasting death. The subtle beauty and pathos of their art has escaped our eyes filled as they are with the marvellous work of Greece, unknown till our own time, the splendid and joyful work of the Renaissance, the mysterious and lovely work of our own day: it remains, nevertheless, a consummate and exquisite art in its dawn, in its noon, in its decadence, but it seeks to express something we have forgotten, and its secret is for the most part altogether hidden from us. It is from this art, as beautiful in its expression of itself as that of Greece, that Niccolo Pisano turns away, not to Nature, but to Antiquity. The movement which followed, producing while it continued almost all that is to-day gathered in the Bargello, together with much else that is still happily where it was born, is as it were an appeal from Antiquity to Life, to Nature. In the simplicity and impulse of this movement, so spontaneous, so touching, so full of a sense of beauty, which sometimes, though not often, becomes prettiness, the art of sculpture, awakened at last from the mysticism of the Middle Age, seems to look back with longing to the antique world, which it would fain claim as its brother, and after a little moment in the sun falls again into a sort of mysticism, a new kingdom of the spirit with Michelangelo, and of the senses merely with Sansovino and Giovanni da Bologna. Really Tuscan in its birth, the art of the Quattrocento became at last almost wholly Florentine, a flower of the Val d'Arno or of the hills about it, where even to-day at Settignano, at Fiesole, at Majano, at Rovezzano, you may see the sculptors at work in an open bottega by the roadside, the rough-hewn marble standing here and there in many sizes and shapes, the chips and fragments strewing the highway. In the twilight of this new dawn of the love of nature, perhaps the first figure we may descry is Piero di Giovanni Tedesco (1386-1402), who carved the second south door of the Duomo about 1398, where amid so many lovely natural things, the fig leaf and the oak leaf and the vine, you may see the lion and the ox, the dog and the snail, and man too; little fantastic children peeping out from the foliage, or blowing through musical reeds, or playing with a kitten, tiny naked creatures full of life and gladness.