Here in the Bargello it is chiefly that art of the fifteenth century that we see in all its beauty and realism:  and though for the proper understanding of it some knowledge of its derivation might seem to be necessary, a knowledge not to be had in the Museo itself, it is really a new impulse in sculpture, different from, though maybe directed by, that older art which we come upon, and may watch there, in its dawn and in its splendour, till with Bandinelli and the pupils of Michelangelo it loses itself in a noisy grandiosity, a futile gesticulation.

Realism, I said in speaking of the character of this fifteenth century work, and indeed it is just there that we come upon the very thought of the time.  Sculpture is no longer content with mere beauty, it has divined that something is wanting, yes, even in the almost miraculous work of Niccolo Pisano himself; is it only an expression of character, of the passing moment, of movement that is lacking, or something comprising all these things—­some indefinable radiance which is very life itself?  It is this question which seems to have presented itself to the sculptors of the fifteenth century:  and their work is their answer to it.

For even as the philosophers and alchemists had sought so patiently for life, for the very essence of it, through all the years of the Middle Age, so art now set out in search of it, the greatest treasure of all, and seems to have found it at last, not hardly or hidden away in some precipitous place of stones, or among the tombs, but as a little child playing among the flowers.

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.