I will select the example of weaving, or, more precisely, weaving of wool. In the first place, all possessions are either productive or preventive; of the preventive sort are spells and antidotes, divine and human, and also defences, and defences are either arms or screens, and screens are veils and also shields against heat and cold, and shields against heat and cold are shelters and coverings, and coverings are blankets or garments, and garments are in one piece or have many parts; and of these latter, some are stitched and others are fastened, and of these again some are made of fibres of plants and some of hair, and of these some are cemented with water and earth, and some are fastened with their own material; the latter are called clothes, and are made by the art of clothing, from which the art of weaving differs only in name, as the political differs from the royal science. Thus we have drawn several distinctions, but as yet have not distinguished the weaving of garments from the kindred and cooperative arts. For the first process to which the material is subjected is the opposite of weaving—I mean carding. And the art of carding, and the whole art of the fuller and the mender, are concerned with the treatment and production of clothes, as well as the art of weaving. Again, there are the arts which make the weaver’s tools. And if we say that the weaver’s art is the greatest and noblest of those which have to do with woollen garments—this, although true, is not sufficiently distinct; because these other arts require to be first cleared away. Let us proceed, then, by regular steps:—There are causal or principal, and cooperative or subordinate arts. To the causal class belong the arts of washing and mending, of carding and spinning the threads, and the other arts of working in wool; these are chiefly of two kinds, falling under the two great categories of composition and division. Carding is of the latter sort. But our concern is chiefly with that part of the art of wool-working which composes, and of which one kind twists and the other interlaces the threads, whether the firmer texture of the warp or the looser texture of the woof. These are adapted to each other, and the orderly composition of them forms a woollen garment. And the art which presides over these operations is the art of weaving.
But why did we go through this circuitous process, instead of saying at once that weaving is the art of entwining the warp and the woof? In order that our labour may not seem to be lost, I must explain the whole nature of excess and defect. There are two arts of measuring—one is concerned with relative size, and the other has reference to a mean or standard of what is meet. The difference between good and evil is the difference between a mean or measure and excess or defect. All things require to be compared, not only with one another, but with the mean, without which there would be no beauty and no art, whether the art of the statesman or the art of weaving or any other; for all the arts guard against excess or defect, which are real evils. This we must endeavour to show, if the arts are to exist; and the proof of this will be a harder piece of work than the demonstration of the existence of not-being which we proved in our discussion about the Sophist. At present I am content with the indirect proof that the existence of such a standard is necessary to the existence of the arts. The standard or measure, which we are now only applying to the arts, may be some day required with a view to the demonstration of absolute truth.
We may now divide this art of measurement into two parts; placing in the one part all the arts which measure the relative size or number of objects, and in the other all those which depend upon a mean or standard. Many accomplished men say that the art of measurement has to do with all things, but these persons, although in this notion of theirs they may very likely be right, are apt to fail in seeing the differences of classes—they jumble together in one the “more” and the “too much,” which are very different things. Whereas the right way is to find the differences of classes, and to comprehend the things which have any affinity under the same class.
I will make one more observation by the way. When a pupil at a school is asked the letters which make up a particular word, is he not asked with a view to his knowing the same letters in all words? And our enquiry about the Statesman in like manner is intended not only to improve our knowledge of politics, but our reasoning powers generally. Still less would anyone analyze the nature of weaving for its own sake. There is no difficulty in exhibiting sensible images, but the greatest and noblest truths have no outward form adapted to the eye of sense, and are only revealed in thought. And all that we are now saying is said for the sake of them. I make these remarks, because I want you to get rid of any impression that our discussion about weaving and about the reversal of the universe, and the other discussion about the Sophist and not-being, were tedious and irrelevant. Please to observe that they can only be fairly judged when compared with what is meet; and yet not
