A thing thou beholdest is easier of belief than that thou hearest, but whatever is both heard and seen we grasp more firmly and lay hold on more securely. I will therefore do the work in both ways, that thus I may be better understood. Whosoever will, therefore, let him hear and see what I say, do, and teach, for I hope it may be of service and not for a hindrance to the better arts, nor lead thee to neglect better things. I hear moreover of no writer in modern times by whom aught hath been written and made known which I might read for my improvement. For some hide their art in great secrecy, and others write about things whereof they know nothing, so that their words are nowise better than mere noise, as he that knoweth somewhat is swift to discover. I therefore will write down with God's help the little that I know. Though many will scorn it I am not troubled, for I well know that it is easier to cast blame on a thing than to make anything better. Moreover, I will expound my meaning as clearly and plainly as I can; and, were it possible, I would gladly give everything I know to the light, for the good of cunning students who prize such art more highly than silver or gold. I further admonish all who have any knowledge in these matters that they write it down. Do it truly and plainly, not toilsomely and at great length, for the sake of those who seek and are glad to learn, to the great honour of God and your own praise. If I then set something burning and ye all add to it with skilful furthering, a blaze may in time arise therefrom which shall shine throughout the whole world. I shall here apply to what is to be called beautiful the same touchstone as that by which we decide what is right. For as what all the world prizeth as right we hold to be right, so what all the world esteemeth beautiful that will we also hold for beautiful, and ourselves strive to produce the like. No one need blindly follow this theory of mine as though it were quite perfect, for human nature has not yet so far degenerated that another man cannot discover something better. So each may use my teaching as long as it seems good to him, or until he finds something better. Where he is not willing to accept it, he may well hold that this doctrine is not written for him, but for others who are willing. That must be a strangely dull head which never trusts itself to find out anything fresh, but only travels along the old path, simply following others and not daring to reflect for itself. For it beseems each understanding, in following another, not to despair of itself discovering something better. If that is done, there remaineth no doubt but that in time this art will again reach the perfection it attained amongst the ancients.