An artist worthy of the name should express all the truth of nature, not only the exterior truth, but also, and above all, the inner truth.
When a good sculptor models a torso, he not only represents the muscles, but the life which animates them — more than the life, the force that fashioned them and communicated to them, it may be, grace or strength, or amorous charm, or indomitable will.
In the works of Michael Angelo, the creative force seems to rumble; in those of Luca della Robbia it smiles divinely. So each sculptor, following his temperament, lends to nature a soul either terrible or gentle.

p. 178 - Art, 1912 - Ch. Mystery in Art