A harmonious design requires that nothing be added or taken away.
Architects should be educated, skillful with the pencil, instructed in geometry, know much history, have followed the philosophers with attention, understand music, have some knowledge of medicine, know the opinions of the jurists, and be acquainted with astronomy and the theory of the heavens.
Building well has three conditions: firmness, commodity, and delight.
Pictures should not be given approbation which are not likenesses of reality; even if they are refined creations executed with artistic skill.