Finally, to take the _third_ example, poetry proceeds through speech within the limits of a self-contained _action_, which it at the same time makes an object of its presentment, and consequently is able to ally itself closely to music, gesture, mimicry, and the dance. This is _dramatic_ art, in which man, in all that the term implies[27], creatively presents the work of art which is the product of human life. These five arts form the system of realized and actual art, essentially determined by itself and differentiated as such. In addition to them there are no doubt other incomplete arts, for example, the arts of gardening and dance. These we shall only refer to incidentally as the opportunity recurs. A philosophical investigation must perforce restrict itself entirely to distinctions referable to the notion, and develop and grasp these adequate and veritable modes of embodiment. Nature and reality is not, it is true, confined to these circumscribed limits, but is more liberal in its movement, and we not unfrequently hear it made a matter of praise that in this respect the products of genius are perforce compelled to expand themselves beyond just such limitations. In Nature, however, transitional organisms of either hybrid or amphibian type, instead of emphasizing the spontaneity and excellence of Nature, merely demonstrate its inability to hold fast to the essential differentiations of species which are rooted in that process, or to prevent their deterioration before external conditions and influences. The same thing may be affirmed in art with regard to these intermediate forms, although the same are capable of producing much, too, that delights us, is full of charm and utility, albeit not in the highest class of perfection.