Now the constitution of Beauty can be only the means to the end of Beauty,--that combination of qualities in the object which will bring about the end fixed by philosophical definition. The end is general; the means may be different kinds. Evidently, then, the philosophical definition cannot be applied directly to the object until the possibilities, conditions, and limitations of that object's fitness for the purpose assigned are known. We cannot ask, Does the Sistine Madonna express the Idea of Sense? until we know all possibilities and conditions of the visual for attaining that expression. But, indeed, the consideration of causes and effects suggests at once that natural science must guide further investigation. Philosophy must lay down what Beauty has to do, but since it is in our experience of Beauty that its end is accomplished, since the analysis of such experience and the study of its contributing elements is a work of the natural science of such experience--it would follow that psychology must deal with the various means through which this end is to be reached. Thus we see that Fechner's reproach is unjustified. Those concepts which are too general to apply to particular cases are not meant to do so. If a general concept expresses, as it should, the place of Beauty in the hierarchy of metaphysical values, it is for the psychologist of aesthetics to develop the means by which that end can be reached in the various realms in which works of art are found. Nor can we agree with Santayana's dictum<1> that philosophical aesthetics confuses the import of an experience with the explanation of its cause. It need not. The aesthetic experience is indeed caused by the beautiful object, but the beautiful object itself is caused by the possibility of the aesthetic experience,-- beauty as an end under the conditions of human perception. Thus the Nature of Beauty is related to its import, or meaning, or end, as means to that end; and therefore the import of an experience may well point out to us the constitution of the cause of that experience. A work of art, a piece of nature, is judged by its degree of attainment to that end; the explanation of its beauty--of its degree of attainment, that is--is found in the effect of its elements, according to psychological laws, on the aesthetic subject. <1> The Sense of Beauty, 1898. Intro.