Uccello, as I have said, was the first representative of two strong tendencies in Florentine painting—of art for dexterity’s sake, and art for scientific purposes. Andrea del Castagno, while also unable to resist the fascination of mere science and dexterity, had too much artistic genius to succumb to either. He was endowed with great sense for the significant, although, it is true, not enough to save him completely from the pitfalls which beset all Florentines, and even less from one more peculiar to himself—the tendency to communicate at any cost a feeling of power.