How thoroughly he comprehended the classic spirit is proved by the bronze patera wrought for his patron Ruberto Martelli, and by the frieze of the triumphant Bacchus.[87] Yet the great achievements of his genius were Christian in their sentiment and realistic in their style.

The bronze "Magdalen" of the Florentine Baptistery and the bronze "Baptist" of the Duomo at Siena[88] are executed with an unrelenting materialism, not alien indeed to the sincerity of classic art, but divergent from antique tradition, inasmuch as the ideas of repentant and prophetic asceticism had no place in Greek mythology.
Donatello, with the uncompromising candour of an artist bent on marking character, felt that he was bound to seize the very pith and kernel of his subject.

If a Magdalen were demanded of him, he would not condescend to model a Venus and then place a book and skull upon a rock beside her; nor did he imagine that the bloom and beauty of a laughing Faun were fitting attributes for the preacher of repentance.

It remained for later artists, intoxicated with antique loveliness and corroded with worldly scepticism, to reproduce the outward semblance of Greek deities under the pretence of setting forth the myths of Christianity.

Such compromise had not occurred to Donatello.