...(another's) opinion; and consider well and think well whether the one who blames you has cause to blame you or not; and if you find that he does, put it right; and if you find that he does not, make as though you had not understood him; or, if he is a man you esteem, show him by reasoning how he is mistaken.

[76] That in works of importance a man must never trust so much in his own memory that he scorns to draw from nature. The master who should give himself to believe that he can keep within himself all the forms and effects of nature would certainly seem to me to be adorned with much ignorance; seeing that these effects are infinite, and our memory is not of such capacity as to suffice. Therefore you, painter, take care that greed for gain does not overcome in you the honour of the art, for the gain of honour is far greater than the honour of riches. So that, for these and other reasons that might be given, you will first attend with drawing to give in demonstrative form to the eye the intention and the invention first formed in your imagination. Then go on removing and adding until you are satisfied; then have men arranged, clothed or nude, in the manner you have ordered upon the work, and see that, by measure and size subject to perspective, no part of the work passes that is not well considered by reason and by the effects of nature. And this will be the way to make yourself honoured by your art.

[77] b. Of those who blame those who draw on feast days, and who investigate the works of God. Among the number of the foolish there is a certain sect, called hypocrites, who continually study to deceive themselves and others, but others more than themselves;