If Giovanni Pisano developed the dramatic and emphatic qualities of Gothic sculpture, Andrea was attracted to its allegories; if Giovanni infused romantic vehemence of feeling into the frigid classicism of his father, Andrea diverged upon another track of picturesque delineation.

A new sun had now arisen in the heavens of art.

This was the sun of Giotto, whose genius, eminently pictorial, brought the Italians to a true sense of their aesthetical vocation, illuminating with its brightness the elder and more technically finished craft of the stone-carver.

Sculpture, which in the school of Niccola Pisano had been subordinate to architecture, became a sub-species of painting in the hands of Andrea.
It was thus, as I have elsewhere stated, that the twofold doom of plastic art in Italy was accomplished.

In order to embody the ideas of Christianity, art had to think more of expression than of pure form.
Expression is the special sphere of painting; and therefore sculpture followed the lead of the sister art, as soon as painting was strong enough to give that lead, instead of remaining, as in Greece, the mistress of her own domain.