...but in truth they deceive themselves more than others. And these are they who reprove the painters who study, on feast days, the things pertaining to the true knowledge of all the figures that the works of nature possess, and who with diligence strive to acquire the knowledge of them, so far as is possible to them. But let such reprovers be silent, for this is the way to know the maker of so many marvellous things, and this is the way to love so great an inventor; for in truth great love is born of great knowledge of the thing that is loved, and if you do not know it, little or nothing will you be able to love it. And if you love it for the good you expect from it, and not for its supreme worth, you do as the dog that wags its tail and makes festivity, rising up toward him who can give it a bone; but if it knew the worth of such a man it would love him much more, if that worth were suited to its purpose.

[78] a. Of the variety of figures. The painter must seek to be universal, for it lacks much dignity in him to do one thing well and another badly: like many who study only the measured and proportioned nude, and do not seek out its variety; for a man may be proportioned and yet be stout and short, or long and slender, or middling; and he who takes no account of this variety always makes his figures as if from a stamp, so that they seem to be all brothers, a thing that deserves great reproof.

[79] b. Of being universal. It is an easy thing for the man who knows to make himself universal, for all terrestrial animals have a likeness of limbs, that is muscles, nerves and bones, and they vary in nothing save in length or in thickness, as will be demonstrated in the anato-[my]...