...were it not for the aid of light and dark, you could not make those muscles, because you could not see them. The sculptor says that it is he who makes light and dark be born by his removing from the sculpted material; it is answered that not he but nature makes the shadow, and not art; and that if he sculpted in the darkness he would see nothing, because there is no variety; nor even in the mists surrounding the sculpted material with equal brightness would one see anything other than the terminations of the sculpted material within the terminations of the mist that borders it. And I ask you, sculptor, why do you not bring works to that perfection in the open country, surrounded by the uniform universal light of the air, as you do under a particular light that descends from above to illuminate your work? And if you make the shadow be born at your pleasure in removing the material, why do you not likewise make it be born in the sculpted material under the universal light, as you do under the particular light? Certainly you deceive yourself, for it is another master that makes those shadows and lights, to whom you are a servant, only preparing the material where he imprints these accidents. So do not glory in the works of others; for you it is enough to have the lengths and thicknesses of the members of any body and their proportions, and this is your art; the rest, which is the whole, is made by nature, a greater master than you. The sculptor says that he will work in low relief, and will show by way of perspective that which is not in fact there; it is answered that perspective is a member of painting, and that in this case the sculptor makes himself a painter, as was demonstrated before.