The more knowledge you have of these, the more worthy of praise will be your work. And for those things in which you have no practice, do not disdain to copy from nature. When you are painting, you should take a flat mirror and often look at your work within it. It will be seen in reverse, and will appear to be by some other master, and you will be better able to judge of its faults than in any other way. It is also a good plan every now and then to go away and have a little relaxation, for then, when you come back to the work, your judgment will be surer, since to remain constantly at work will cause you to lose the power of judgment. Surely, while one paints one should not reject any man's judgment; for we know very well that a man, even if he be no painter, has knowledge of the forms of another man, and will judge aright whether he is hump-backed, or has one shoulder too high or too low, or whether he has too large a mouth or nose, or other faults; and if we are able rightly to judge the work of nature in men, how much more is it fit to admit that they are able to judge our mistakes. You know how much man may be deceived about his own works, and if you do not know it of yourself, observe it in others, and you will derive benefit from other people's mistakes. Therefore, you should be eager to listen patiently to the views of other men and consider and reflect carefully whether he who finds fault is right or not in blaming you. If you find that he is right, correct your work; but if not, pretend not to have understood him; or show him, if he be a man whom you respect, by sound argument, why it is that he is mistaken in finding fault. _Do Not Disdain to Work from Nature_ A master who let it be understood that his mind could retain all the forms and effects of nature, I should certainly hold to be endowed with great ignorance, since the said effects are infinite, and our memory is not of such capacity as to suffice thereto. Therefore, O painter, see that the greed for gain do not outweigh within you the honour of art, for to gain in honour is a far greater thing than to be honoured for wealth. For these and other reasons that might be adduced, you should endeavour first to demonstrate to the eye, by means of drawing, a suggestion of the intention and of the invention originated first by your imagination. Then proceed, taking from it or adding to it, until you are satisfied with it. Then have men arranged as models, draped or nude, in the manner in which they are disposed in your work, and make the proportions and size in accordance with perspective, so that no part of the work remains that is not counselled by reason as well as by nature.