It is indeed true that the very possibility of a criticism which shall judge of aesthetic excellence must stand or fall with this other question of a beauty in itself, as an objective foundation for criticism. If there is an absolute beauty, it must be possible to work out a system of principles which shall embody its laws,--an aesthetic, in other words; and on the basis of that aesthetic to deliver a well-founded critical judgment. Is there, then, a beauty in itself? And if so, in what does it consist? We can approach such an aesthetic canon in two ways: from the standpoint of philosophy, which develops the idea of beauty as a factor in the system of our absolute values, side by side with the ideas of truth and of morality, or from the standpoint of empirical science. For our present purpose, we may confine ourselves to the empirical facts of psychology and physiology. When I feel the rhythm of poetry, or of perfect prose, which is, of course, in its own way, no less rhythmical, every sensation of sound sends through me a diffusive wave of nervous energy. I am the rhythm because I imitate it in myself. I march to noble music in all my veins, even though I may be sitting decorously by my own hearthstone; and when I sweep with my eyes the outlines of a great picture, the curve of a Greek vase, the arches of a cathedral, every line is lived over again in my own frame. And when rhythm and melody and forms and colors give me pleasure, it is because the imitating impulses and movements that have arisen in me are such as suit, help, heighten my physical organization in general and in particular. It may seem somewhat trivial to say that a curved line is pleasing because the eye is so hung as to move best in it; but we may take it as one instance of the numberless conditions for healthy action which a beautiful form fulfills. A well- composed picture calls up in the spectator just such a balanced relation of impulses of attention and incipient movements as suits an organism which is also balanced--bilateral--in its own impulses to movement, and at the same time stable; and it is the correspondence of the suggested impulses with the natural movement that makes the composition good. Besides the pleasure from the tone relations,--which doubtless can be eventually reduced to something of the same kind,--it is the balance of nervous and muscular tensions and relaxations, of yearnings and satisfactions, which are the subjective side of the beauty of a strain of music. The basis, in short, of any aesthetic experience--poetry, music, painting, and the rest-- is beautiful through its harmony with the conditions offered by our senses, primarily of sight and hearing, and through the harmony of the suggestions and impulses it arouses with the whole organism.