to develop, those elements in painting or in song, which relate to our practical wants and to our speculative faculties so far as they are required for supplying them; these forming the topics of ordinary communication. Thus the emotion from which the sign had originally proceeded becomes gradually effaced; the practical object is alone thought of, and expression becomes more rapid and less emphatic. The process goes on until at last the sign is supposed to have originated in arbitrary convention; though, if this were the case, its universal and spontaneous adoption would be inexplicable. Such, then, is the sociological theory of Language, on which I shall afterwards dwell more fully. I connect it with the whole class of esthetic functions, from which in the lower animals it is not distinguished. For no animal idealizes its song or gesture so far as to rise to anything that can properly be called Art. [Classification of the arts on the principle of decreasing generality, and increasing intensity] To complete our examination of the philosophy of Art, statically viewed, we have now only to speak of the order in which the various arts should be classified. Placed as Art is, midway between Theory and Practice, it is classified on the same principle, the principle, that is of decreasing generality, which I have long ago shown to be applicable to all Positive classifications of whatever kind. We have already obtained from it a scale of the Beautiful, answering in most points to that which was first laid down for the True, and which we applied afterwards to the Good. By following it in the present instance, we shall be enabled to range the arts in the order of their conception and succession, as was done in my Treatise on Positive Philosophy for the various branches of Science and Industry. The arts, then, should be classified by the decreasing generality and the increasing intensity, which involves also increasing technicality, of their modes of expression. In its highest term the esthetic scale connects itself with the scientific scale; and in its lowest with the industrial scale. This is in conformity with the position assigned to Art intermediate between Philosophy and Practical life. Art never becomes disconnected from human interests; but as it becomes less general and more technical, its relation with our higher attributes becomes less intimate, and it is more dependent on inorganic Nature, so that at last the kind of beauty depicted by it is merely material. [Poetry]