If he had to paint a biblical or mythological subject, he avoided landscapes, trees, flowers, birds, beasts, and subordinate groups of figures.

He eschewed the arabesques, the labyrinths of foliage and fruit enclosing pictured panels, the candelabra and gay bands of variegated patterns, which enabled a _quattrocento_ painter, like Gozzoli or Pinturicchio, to produce brilliant and harmonious general effects at a small expenditure of intellectual energy.

Where the human body struck the keynote of the music in a work of art, he judged that such simple adjuncts and naive concessions to the pleasure of the eye should be avoided.

An architectural foundation for the plastic forms to rest on, as plain in structure and as grandiose in line as could be fashioned, must suffice.

These principles he put immediately to the test in his first decorative undertaking.