The origin of this psychological illusion of the ideas or types of things is always to be found in the changing of the empirical classifications created for their own purposes by the natural sciences, into living realities. Thus each art has for its sphere a special category of ideas. Architecture and its derivatives, gardening (and strange to say landscape-painting is included with it), sculpture and animal-painting, historical painting and the higher forms of sculpture, etc., all possess their special ideas. Poetry's chief object is man as idea. Music, on the contrary, does not belong to the hierarchy of the other arts. Schelling had looked upon music as expressing the rhythm of the universe itself. For Schopenhauer, music does not express ideas, but the _Will itself_. The analogies between music and the world, between fundamental notes and crude matter, between the scale and the scale of species, between melody and conscious will, lead Schopenhauer to the conclusion that music is not only an arithmetic, as it appeared to Leibnitz, but indeed a metaphysic: "the occult metaphysical exercise of a soul not knowing that it philosophizes." For Schopenhauer, as for his idealist predecessors, art is beatific. It is the flower of life; he who is plunged in artistic contemplation ceases to be an individual; he is the conscious subject, pure, freed from will, from pain, and from time. Yet in Schopenhauer's system exist elements for a better and a more profound treatment of the problem of art. He could sometimes show himself to be a lucid and acute analyst. For instance, he continually remarks that the categories of space and time are not applicable to art, _but only the general form of representation_. He might have deduced from this that art is the most immediate, not the most lofty grade of consciousness, since it precedes even the ordinary perceptions of space and time. Vico had already observed that this freeing oneself from ordinary perception, this dwelling in imagination, does not really mean an ascent to the level of the Platonic Ideas, but, on the contrary, a redescending to the sphere of immediate intuition, a return to childhood. On the other hand, Schopenhauer had begun to submit the Kantian categories to impartial criticism, and finding the two forms of intuition insufficient, added a third, causality. He also drew comparisons between art and history, and was more successful here than the idealist excogitators of a philosophy of history. Schopenhauer rightly saw that history was irreducible to concepts, that it is the contemplation of the individual, and therefore not a science. Having proceeded thus far, he might have gone further, and realized that the material of history is always the particular in its particularity, that of art what is and always is identical. But he preferred to execute a variation on the general motive that was in fashion at this time.